Posts by kbd512

kbd512 · Not So Free Chat

tahanson43206,

I would note that the world taken as a whole does NOT appear to be in population crisis!

I see that Calliban has already responded to this fictitious idea. The birth rate in virtually all developed countries is well below replacement rate. We're not growing. We're not even "mostly staying the same". Real population in all countries that matter at a global scale, from nations in Africa, the Americas, Asia, Europe, and the Middle East, is crashing and burning. Even the birth rate in India, which is actually the world's most populous nation, not China, is already below replacement level. We can afford to play a shell game with people a bit longer, as a nation of immigrants, but even our population won't last forever because there won't be enough people to import from elsewhere.

Sub-Saharan Africa is the world's only region with an above-replacement total fertility rate (TFR), currently estimated from 4.3 to 4.6.

Sub-Saharan Africa's crude birth rate is dropping like a rock as well. Anyone who thinks nothing is wrong is either a Malthusian or they don't pay much attention to the numbers. The stats don't paint a very pretty picture.

kbd512 · Human missions

If we produced NTO/MMH or NTO/HAN on Mars, how many kilos of N2 would we need to deliver for performance equivalent to LOX/LCH4?:

NTO/MMH
2,852.556kg of N2 in 9,368kg of NTO
2,997.44kg of N2 in 4,930kg of MMH
5,849.996kg of N2 in total

NTO/HAN
2,852.556kg of N2 in 9,368kg of NTO
1,814.148kg of N2 in 5,183.28kg of HAN (weighs a lot more than MMH but occupies 50% less tank volume for equal Delta-V)
4,666.704kg of N2 in total

Only 10.624m^3 of total tank volume is required for NTO/HAN. HAN also provides a 2% to 3% Isp improvement over NTO/MMH, but I ignored that in the propellant mass computation, and simply divided MMH propellant volume by 2 and then multiplied by HAN's bulk density of 1,840kg/m^3. Tank volume is so much smaller for a NTO/HAN powered MAV as compared to a LOX/LCO or LOX/LCH4 that it's silly.

If we're going to ship part of a propellant load to Mars, then it should be N2 so we can make NTO/HAN storable propellants. Nitrogen stored at 1,000bar of pressure in CFRP Type IV tanks (normally used to hold H2 at the same pressure), is 1,129.9kg/m^3, so 4.13m^3 of tank volume in total. We probably wouln't ship pure N2 to Mars, though, because NTO is normally made by catalytic oxidation of Ammonia. LNH3 is much easier to store at very modest pressure, and contains the Hydrogen required to make MMH or HAN.

NTO Chemical Reactions:
4NH3 + 5O2 → 4NO + 6H2O
2NO + O2 → 2NO2
2NO2 ⇌ N2O4

HAN Chemical Reactions:
Use the Ostwald process to make nitric acid (HNO3). Ammonia and air or oxygen are passed over a Platinum-Rhodium catalyst, yielding Nitric Oxide (NO). NO is further oxidized using more Oxygen or air, into Nitrogen Dioxide (NO2). NO2 is dissolved into water to create Nitric Acid (HNO3) and NO which is recycled back to the first step of the reaction.

For making the Hydroxylamine (NH2OH), apparently there's this:
A recent method involves using plasma-electrochemical cascade pathways (PECP) to synthesize hydroxylamine directly from ambient air and water at mild conditions. Direct synthesis of NH2OH ordinary air and water under mild conditions sounds good to me.

Hydroxylamine (NH2OH) is a base, and nitric acid (HNO3) is a strong acid. When these two react, they neutralize each other, forming hydroxylammonium nitrate (NH3OHNO3) and water (H2O).

After we're done processing the reactants using Mars-sourced Carbon, Oxygen, and Hydrogen, NTO/HAN no longer requires any energy input for cryogenic cooling or heating. MMH does require a modest amount of heating to prevent freezing and subsequent decomposition as it's reheated.

Relative to the massive power requirements associated with crycocooling tons of propellants for up to 5 years, this seems like we could take our Acme Chemistry Starter Set with us to Mars to whip-up a batch of storable propellants.

kbd512 · Not So Free Chat

According to Peter, all those brands were eventually going to fail if they continued doing "business as usual" until China's demographic collapse precluded meaningful participation in the global trade system as an export-led economy. American companies that moved operations overseas did so at the expense of American jobs, so if they're now history as a result, then at least everyone else will know why "fast money" comes with "slow painful problems". American and Chinese workers will not be held captive to a slow-motion train wreck over the next 20 years. The pain is here, we're all eating our slice of humble pie, and then we can move on to endeavors that are actually good for our respective countries. I hope this leads to China's government cleaning up their incredibly polluted environment so that their people can lead better lives by primarily making things for their own domestic consumption.

The warning signs that China was contracting were all over the place, but nobody wanted to see how the sausage was being made, so-to-speak. Now there's no ignoring that painfully obvious demographic decline / early stage collapse. Absent radical change, China's demographics are terminal. They vastly over-stated their population to obfuscate massive internal problems at the family unit level. Their government and corporations have never been good faith actors when it comes to intellectual property or human rights. Good riddance to that, and I sincerely hope average American and Chinese workers get a better deal from their government. We've been crapped on by these cretins for the last 40 years. I'm sick of them, and I'll bet most people who are not part of the upper butt-crust of society are equally fed up with the predatory government / major corporation manipulated form of capitalism.

kbd512 · Human missions

RobertDyck,

If the mass of the required ISPP equipment exceeds the mass of a fully fueled MAV using traditional storable propellants like NTO/MMH, then you've saved nothing. I added the mass of the ISPP lander to the mass of the MAV lander, because that's how much mass you have to ship all the way to Mars to do ISPP. The landed mass of their MAV design is already very significant with the LCH4 fuel included, plus they're sending additional landers containing KiloPower reactors and ISPP plant equipment. If the mass of both of those vehicles exceeds the mass of a MAV with NTO/MMH, and it does, then there's no delivered mass improvement associated with doing that. NASA's DRM 5 MAV design is shipping ALL of the LCH4 to Mars, inside the MAV, and keeping it cold for up to 5 years.

In short, it's a series of diversionary side quest hurdles to leap over, which are intended to act as toll booths to inhibit human exploration of Mars while spending a lot of money that accomplishes a lot of nothing relevant to exploration. At the end of the day, they'll have spent a lot of money on scientifically interesting experiments that don't contribute to real world accomplishments, such as human exploration of Mars.

ISPP will become a hard requirement for colonization, but whatever NASA is up to at the present time is solely intended to prevent human exploration of Mars or the moon while claiming the opposite. That's why there's no flight-tested hardware ready to go. Orion and SLS were more of the same. Congress never cared about actually returning to the moon, merely spending more public money in their respective districts while pointlessly yapping about how "sciency" they were.

LOX/LCO combustion temperatures and exhaust product masses would seem to indicate that 300s is possible, but there could be other factors that act to reduce Isp, such as reaction rates. We don't have a lot of experimental data for LOX/LCO. I'll accept your say-so on this, because you may very well be correct, as long as you show me that you've done basic due diligence on what NASA is proposing to do here as it pertains to the landed useful payload mass for both components necessary for minimal ISPP, in terms of landed tonnage. I think NTO/MMH results in the lightest practical MAV design, to the point that we can land 2 MAVs for the same useful delivered payload tonnage to the surface of Mars and same cost.

If the tonnage for a partial LOX-only ISPP MAV exceeds the mass of a NTO/MMH powered MAV, then arguing over how much mass ISPP could possibly save is moot, most importantly because no landed payload mass was actually saved. I'm only interested in the lowest cost / lightest / most practical design that we can build using technology we actually have, on-time and within budget.

Do you remember when we discussed this particular MAV design?:
System Design of a Mars Ascent Vehicle by Scott Alan Geels, 1990

1980s materials, engine, power, ECLSS, computer tech:
Total Landed Vehicle Wet Mass (NTO/MMH) for 3 crew: 14,093.5kg

2020s materials, engine, power, ECLSS, computer tech:
NASA DRM 5 MAV Total Landed Vehicle Wet Mass 1 sol (LCH4 only; LOX ISPP) for 4 crew: 17,078kg
NASA DRM 5 MAV Total Landed Vehicle Wet Mass 5 sols (LCH4 only; LOX ISPP) for 4 crew: 18,415kg

There's also another lander containing the ISPP equipment (reactors plus propellant plant) that weighs almost as much as their MAV for LOX-only ISPP. Therefore, no mass is ever saved. We could land a second complete MAV if we still wanted to spend the same money delivering the same tonnage.

Conclusion:
NASA's MAV is a side quest that detracts from the primary exploration mission and costs a lot of time and money to develop. It's something that will be useful for colonization, but not exploration.

kbd512 · Meta New Mars

tahanson43206,

Every crewed American spacecraft since Gemini, as well as nearly every robotic probe, has used some kind of Hydrazine-based propellant for RCS, mostly NTO/MMH, but sometimes Aerozine-50 or UDMH. I think the Mercury program used something weird like Hydrogen Peroxide monopropellant decomposition. Dragon, Orion, Starliner, and Dream Chaser all use NTO/MMH. Both stages of the Lunar Excursion Module used Hydrazine-based propellants as well. All other crewed spacecraft used by all other space-faring nations use Hydrazine-based monopropellants and bipropellants as well.

There's no serious effort to replace these oxidizers and fuels, although certain Hydrazine substitutes such as Hydroxyl-Ammonium Nitrate (HAN) or similar chemicals can serve as monopropellants with improved Specific Impulse over Hydrazines and greatly improved Density Impulse. For equal Total Impulse, HAN only requires half as much propellant tank volume as MMH. Accidentally freezing HAN does no damage to the propellant or tankage, unlike Hydrazines. HAN poses little to no danger of an accidental exothermic decomposition / thermal runaway, unlike Hydrazines. That means switching to HAN from MMH provides one of those rare all-around performance improvements. NTO/HAN only provides a modest Isp increase over NTO/MMH (2% to 3%), but HAN is far less toxic than Hydrazine, as it's only mildly acidic. No fuel line blow-down and double check valve is required using HAN. NTO (N2O4) is very toxic and very oxidizing / corrosive, but not quite as toxic to humans as Hydrazine-derivative fuels. LOX is also pretty nasty stuff to work with, just in case someone thinks pure O2 is significantly less problematic than NTO.

All things considered, we should probably make the switch from MMH as our fuel of choice to HAN because it's an improvement over MMH in every sense of the word, but keep the NTO (N2O4) oxidizer, despite its toxicity.

You can read more about HAN monopropellant here:
GPIM (Green Propellant Infusion Mission)

kbd512 · Human missions

The more I study NASA's MAV design, the more it looks like pointless complexification to keep engineers and vendors busy, or to prove that they can do some specific set of technology demonstrations that don't function in a way that minimizes the mass, cost, and development timeline of the design. I'm going to work on something that doesn't add complexity and mass for no mission benefit.

If we're going to bring the fuel all the way from Earth, then we're going to bring NTO/MMH. At least that requires no ISPP mass, no brand new engine development, and no cryocooling until ascent from Mars. We get 6,000kg of mass back by not having to bring the reactors, plus whatever mass the support equipment requires to robotically emplace the reactors without any humans present, plus the entire ISPP plant mass.

For a 5,314kg dry vehicle mass and 19,612kg wet mass at ignition, I only need 2X Aestus-II / RS-72 pump-fed NTO/MMH engines, which are used by the Ariane rocket's upper stage. That's quite literally less than half the mass of NASA's ridiculous vehicle design which still uses smaller NTO/MMH engines on the cruise stage used to deliver the MAV to Mars. If we're gonna load Hydrazine anyway, then we may as well cross-out all this pointless complexification associated wtih keeping the Methane liquid from the point in time that the vehicle is launched from Earth to the point in time when someone hits the button on Mars, up to 5 years later, robotic emplacement of the KiloPower reactors, making all the propellant before the crew lands, etc. The entire point of this mission is to explore Mars, not babysit the MAV.

9,368kg (7.807m^3) NTO, 4,930kg (5.634m^3) MMH, 13.441m^3 total propellant volume for the same Delta-V that the LOX/LCH4 provides.

That is less total propellant volume than the LCH4 tank volume for NASA's MAV, and it absolutely will weigh less than all the equipment that would otherwise be required. If we do ISPP at all for the first mission, LOX/LCO all the way. LCH4 makes no sense. Otherwise, NTO/MMH for the win.

kbd512 · Human missions

RobertDyck,

I also think we should be looking for a suitable water source during the very first mission, but "betting the farm" on finding water that we can readily use for propellant production is a bad idea. We have no clue what Martian water is mixed with because we've never even attempted to drill through the ground to obtain samples. If we knew exactly where to stick our soda straw, because we knew how far down the water table is, what was dissolved into that ice, and how much was there, then let's devise a way to obtain some of that water so we can make the best rocket fuel we can get. We need to actually do that at least once before we stake human lives on obtaining local water.

Why did we not undertake that effort already if Mars was the ultimate exploration target, as NASA has claimed since the Apollo program?

I have no idea, but it clearly wasn't a priority in the past. We need more than lip service paid to the idea.

kbd512 · Human missions

RobertDyck,

Thanks for that contribution. That bumps our power output to 103,308,870Wh per sol per 250m^2 array. From doing the math on their square 27cm^2 cells, 1m^2 of photovoltaic cells weighs 839.16g, the lowest practical weight for a T1200 composite and honeycomb backer board (2 ply per face sheet, around the Kevlar honeycomb sandwich core) is about 1kg per square meter, and the wiring, if CNT / Copper composite (~50% more electrically conductive than Copper alone and less than half the weight), would add another 1kg to get the power off the panel. A small dual-axis stand / Sun tracker for the panel would weigh another 1kg, so 4kg per 1m^2 panel, or 1,000kg per 250m^2 array.

Output will drop during the winter months, but overall the array and battery bank is about equal in weight to a 10kWe KiloPower reactor. We cannot operate the ISPP equipment without a battery bank. Heating up and cooling down MOXIE once per day is a better than average way to crack the ceramic in the solid oxide fuel cell that produces CO and O2.

From the DRM 5 addendum document provided by NASA, their state-of-the-art cryocooler consumes 1,200W of power to provide 150W of cooling capacity to remove heat from the gases undergoing liquefaction. We need to remove 2,768,975Wh of thermal energy from 47,304kg of LOX/LCO propellant to lower their temperatures from 298.15K to just below their respective boiling points, which implies 22,151,800Wh of input electrical power to the cryocoolers, for a constant power draw of 2,528.74W.

Revised Energy Inputs Total:
116,147,604Wh to obtain 47,304kg of LOX/LCO propellant.

We would thus require 2X 250m^2 arrays of those Spectrolabs cells to ensure our ISPP processing time remains below 1 year.

Each LEU-fueled 10kWe KiloPower unit is expected to weigh at least 2,000kg and NASA intended to bring 3 of them, so 6,000kg in total, which provides 262,800,000Wh over a sol. If we have a 6,000kg mass budget to work with for the power generating equipment, then I will opt for 3X of those 250m^2 arrays and 3,000kg worth of batteries in properly protected enclosures.

Amprius offers 500Wh/kg and 1,300Wh/L prismatic cell Lithium-ion batteries, rated for 1,300 full charge / discharge cycles before significant degradation occurs, for commercial sale. NASA presently uses GS Yuasa prismatic cells aboard ISS, so they're familiar with how to design enclosures for the prismatic variety. Presuming our battery pack enclosure roughly halves the stated Wh/kg value of the cells themselves, a 3,000kg battery bank can store 750kWh worth of power (46,875 Watts per hour over 16 hours, if fully discharged), which should be enough to keep that solid oxide fuel cell very very hot and the propellant very very cold during the night.

kbd512 · Interplanetary transportation

Calliban,

What you're describing sounds a lot like the M2P2 (Mini-Magnetospheric Plasma Propulsion) system proposed by Dr Winglee et al, IIRC. His group did a bit of work on refining it and developing some hardware for that concept, but it was only ever tested in a lab, so far as I know.

kbd512 · Interplanetary transportation

Moore’s Law Meet Musk’s Law: The Underappreciated Story of SpaceX and the Stunning Decline in Launch Costs - American Enterprise Institute

Here's a "Compromise and Conceit" blog posting from the user "faustusnotes", who is critical of SpaceX launch cost claims, which I've included for balanced / honest / factual reporting:

How Much do SpaceX Rocket Launches Really Cost?

Conclusion
The final conclusion of all of this is that SpaceX are lying about the price to launch stuff into space on their rockets, and the media are uncritically repeating their fabricated price without checking its validity, comparing it with other prices available on the SpaceX website, comparing it with the prices that would be implied by SpaceX’s government contracts, or looking at the evidence from actual SpaceX flight data. The true price of launching stuff into space on a SpaceX rocket is likely more like $6,000/kg, more than twice the number they are citing.
Furthermore, this price is not a revolutionary drop in the cost of launching, and is in fact entirely consistent with the historical trend in US rocket launch prices. The best prices Falcon X manages to achieve are also not unusual, being simply normal prices for a Chinese or Russian rocket. The claim that SpaceX is doing anything special to drive down rocket prices is just more Muskrat hype, with no basis in reality at all.
It is also clear that reusability has not driven down the price of launches. Reusability incurs a payload penalty, since the rocket needs to be stronger and some fuel needs to be reserved for re-entry. Reusability is also not a radical new idea: the space shuttle’s booster rockets were reusable, and SpaceX’s sole advance on this 1980s technology has been to land them on a barge rather than beside one. This likely speeds up the time to return them to use, and slightly reduces the penalty incurred for robustness (since the rockets don’t need to resist the crash into the water) but it also significantly increases the amount of reserve fuel needed for re-entry. In fact United Launch Alliance (ULA), a SpaceX competitor, analysed reusability and found that it does not necessarily deliver much cost benefit for these reasons. There are formulae for the calculation of how many re-uses are needed for a recyclable rocket to be cheaper than an expendable one, available at the documents linked in this discussion board, and they suggest that in general it only reduces costs in the long-run by about 5%. So no, SpaceX has not revolutionized anything in this regard either.
So in conclusion, SpaceX is not revolutionizing space travel, it has not driven prices down at all relative to the long-term trend, launches with SpaceX cost considerably more than their PR suggests, and SpaceX is essentially a low-quality internet service provider with a side-hustle in military contracting, being heavily propped up by murky venture capital. Elon Musk is not, and never will be, anything except a scammer, and in future decades people will look back on how he was viewed in this period with confusion, scorn and disbelief.

I feel as though the user who posted that is likely unaware of some of the minutia of government launch contracts. One aspect that greatly increases cost is the government's refusal to purchase launch insurance.

When the government doesn't indemnify for liability, launch companies need to purchase more insurance to cover potential losses. This increases their insurance premiums, which they then have to factor into their launch prices to remain profitable, according to the GAO.

As one should know, launching giant rockets is a risky business, the government expects its launches to go off without a hitch, you will be held liable if a rocket that Uncle Sam paid for fails to go into orbit, and any insurance companies concerned with self-preservation will summarily charge Acme Rocket Corp an arm and a leg in order to pay out if their rocket fails in a way that affects mission success as the government defines it. Some of the launch contracts can literally double in price as a result. Communist countries may not and probably do not operate the same way. They probably force the company that paid for a launch to eat the cost of the launch and payload if their rocket fails. We don't do that in the western world, so we're at a financial disadvantage there. However, if we can still bring launch prices into alignment with the communists, then we must be doing something right because even after those additional costs, we're becoming more and more competitive on price. That's not a reflection on the actual cost to the service provider to launch their rocket, rather government bureaucracy with zero-defect mentality.

It's notable that ULA did not lower its launch services prices until competition from SpaceX forced them to.

It's even more notable that virtually every nation that launches rockets into orbit is now developing LOX/LCH4 engines, because Methane / natural gas is the lowest cost fuel that money can buy. Everyone talked a good game about Methane rocket engine development prior to SpaceX, spent untold millions and billions on engine development, but until serious competition appeared that mandated cheaper fuels to remain competitive on price, nothing stopped "business as usual".

As this chart from the same blog post shows:

First, I will readily admit that Elon Musk is a salesman for his company. They are trying to "sell" their product to new prospective customers, after all, because that is their business. That said, their marginal cost to produce a rocket has to be lower than competitors because they don't have to make a brand new rocket from scratch for each launch. Certain Falcon boosters have now flown more than 10 times. If SpaceX chose to do so, they could easily afford to further reduce their contracted price while remaining profitable.

The poster is also engaging in quite a bit of "cherry picking" on launch services cost by way of false equivalence. For starters, many of the modes of operation of Falcon and Falcon Heavy are not even options for the other rockets on the list. He / she is quite correct about reusability being somewhat dubious as a cost savings benefit when it affects dollars spent per kilo of payload delivered to orbit. However, what rapid reusability clearly does affect is launch cadence. No other nation, let alone a specific launch services provider, comes close to matching SpaceX's launch cadence. When you need a rocket soon, SpaceX usually has something available. Furthermore, when comparing like-for-like launch options, SpaceX easily has the cheapest rocket in terms of dollars spent per kilo of payload delivered to a specified orbit. Whether they choose to charge more for specific services like "ride sharing" is something beyond the simplistic analysis of what purchasing a singular rocket launch for delivery of a singular payload, which truly requires a rocket of a given size, will actually cost the customer.

One real clear indicator that SpaceX does provide the least expensive launch services is the sheer percentage of the total global launch tonnage that SpaceX has been solely responsible for delivering to orbit over the last several years. Does anyone truly believe that someone with the tens of millions of dollars needed to launch any kind of satellite into space is not going to "shop around" to find the best launch prices? How does one imagine they became that wealthy to begin with? I can guarantee it wasn't by only selecting the most expensive option to get the same job done. If cost and schedule matters, as it frequently does, then customers who would otherwise choose to use Soyuz or Proton or Long March are now choosing to do business with SpaceX, because they can be reasonably sure that their payload is going to get into space, on-time and within budget.

Long March 5 is comparable to Falcon 9 Full Thrust (FT) in terms of payload to LEO when Falcon 9 FT is launched in expendable mode, and using Long March 5 does in fact result in a reduced launch cost in terms of dollars per kilogram. However, Falcon 9 FT has launched 454 times since 2018. Long March 5 has only launched 14 times since 2016. Regardless of how much cheaper Long March 5 is on paper, the Chinese haven't launched it more than a literal handful of times over the past 9 years. That means it either has significant technical or operational issues or they cannot mass produce it. I'm going with the former because the latter is a ridiculous proposition. The Chinese mass produce all manner of things. To launch anything into orbit, you first need a fully mission capable rocket sitting on the pad. SpaceX is going like gangbusters when it comes to having rockets ready for flight.

If it sounds like I'm tooting SpaceX's horn a little too loudly, I always have been mightily impressed by how the Soviets and Chinese have operated their space programs on comparative shoestring budgets with smaller cadres of dedicated personnel. If anything, I would assert that the communist system, whatever that is, has been more effective at containing costs over their years of being in the launch services business. Unfortunately, the same system that is so good at containing launch costs also tends to stifle innovation. Only the imposition of an unstoppable external force motivates them to pursue something better.

SpaceX's other up-and-coming competitors, far from being "stick-in-the-mud" types, are innovating their way to more competitive market positions, despite claims that nobody else can do X / Y / Z better than SpaceX. I'm genuinely looking forward to the creative solutions that other launch services providers are devising to undercut SpaceX on cost.

One final note is that everyone's prices have gone up since COVID, so using launch prices that might be 10 years old at this point is not very constructive to the discourse regarding current launch costs and cost-competitiveness within the launch services industry. What I would like to see is a drastic increase in launch cadence, because that tends to minimize costs through streamlining of operations to meet the launch schedule.

Only the Soyuz (2,000 launches prior to replacement with the heavily modified current version), Long March 2/3/4 series (492 launches), Falcon 9 (474 launches), and Proton (430 launches) have comparable flight heritage. Every other launcher is a very distant second. Atlas V is the runner-up (102 launches). All other launch vehicles have even fewer flights.

I do not consider the Kosmos, earlier versions of Atlas, Thor, or Titan derivative launch vehicles to be in the same class as purpose-built orbital launch vehicles. Yes, they provide good service in the past, but only the Titan is in the same payload class as these modern launchers, and Titan launch costs became so great that it was discontinued because it was uneconomical. I guess the Delta series and Space Shuttle also qualify as "work horse" launch vehicles, but once again those were so expensive that they were retired.

kbd512 · Human missions

Using NASA's 226:1 "gear ratio" for propellant / engines / structures masses required to land 1kg on the surface of Mars, we can see that the 8,892kg of LCH4 fuel from the "5 sols" 2019 MAV design refinement, brought all the way from Earth to the surface of Mars, results in the requirement for 2,009,592kg of (mostly propellant) mass to deliver that LCH4 to the surface of Mars. In reality, it's actually worse than that, because additional LOX/LCH4 engines which are not required for Mars ascent are used during Mars EDL to land the MAV. Some of this additional engine power is undoubtedly a result of leaving the heat shield affixed to the lander.

If I understood the document correctly, 8X 100kN LOX/LCH4 engines in total are used by their 5 sols MAV design, yet only 4 are required for ascent. The rest of the engines are not required after EDL. They show engine mass optimization charts wherein more powerful main engines save 1,000kg to 2,000kg of weight in "Figure 12". I think that's a necessary optimization, because it saves 452,000kg of launch weight. If the exploration campaign is only 6 missions, then 2,712t of launch mass is eliminated, which is creeping up on the 3,300t GLOW of a Falcon Heavy heavy lift vehicle, which costs NASA about $95M.

Keeping those LCH4 fuel tanks cold for up to 5 sols, and leak-free, is a fairly tall order. That's another advantage of making all ascent propellant on the surface of Mars, using the Martian atmosphere, at an energy cost on-par with their LOX-only ISPP solution. If you're already making a similar tonnage of LOX from atmospheric CO2, then you may as well collect and liquefy the Carbon Monoxide produced by that process as well.

The 3X 10kWe KiloPower fission reactors NASA proposes to use for their surface exploration campaign can provide 262.8MWh worth of power per year, which is more than sufficient to make enough LOX/LCO propellant from the Martian atmosphere for LOX/LCH4 equivalent Delta-V, and the MAV can be launched and landed using EDL-only propellant in its tanks, when LCO becomes the fuel of choice. The only thing we're changing is adding the energy cost of liquefaction of the Carbon Monoxide instead of dumping it overboard after we get the LOX. Either way, we have to process about as much CO2 because the LOX/LCH4 MAV requires 29,142kg of LOX.

There's not enough LOX/LCO propellant mass increase, relative to LOX/LCH4, for a low Delta-V requirement vehicle (less than half of what is required to achieve orbit here on Earth), to justify the expense and complexity of either making Methane propellant from Martian ground water or shipping Methane to Mars from Earth and keeping it cold for up to 5 years. If you're going to do ISPP for the MAV, then max out that "gear ratio" benefit through simplification of the natural resource processing requirements to only Martian atmosphere processing.

kbd512 · Human missions

NASA's updated / more detailed MAV design, circa 2019:
Update to Mars Ascent Vehicle Design for Human Exploration

kbd512 · Human missions

LOX/LCH4 vs LOX/LCO Propellant Masses and Volumes for NASA's Mars DRM 5.0 1.5-Stage-to-Orbit MAV

Go to Page #114 for an estimated mass breakdown for a LOX/LCH4 powered Mars Ascent Vehicle (MAV):
Human Exploration of Mars Design Reference Architecture 5.0 Addendum

Inert Vehicle Mass: 13,944kg

32,498kg LOX/LCH4 propellant at 369s Isp delivers 4,353.8m/s Delta-V
47,304kg LOX/LCO propellant at 300s Isp delivers 4,353.8m/s Delta-V

14,806kg propellant mass increase for LOX/LCO, as compared to LOX/LCH4

LOX/LCO Mixture Ratio is 0.57143:1
Oxidizer mass = Mixture Ratio * Fuel mass

20,273kg LOX (17.768m^3); 27,031kg LCO (25.695m^3); 43.463m^3 total propellant volume
24,956kg LOX (21.872m^3); 7,542kg LCH4 (17.838m^3); 39.71m^3 total propellant volume

3.753m^3 total propellant volume increase for LOX/LCO, as compared to LOX/LCH4, for equal Delta-V, and 9.45% volume increase over LOX/LCH4

According to Dr Robert Zubrin, liquid CO2 can be obtained from the Martian atmosphere for an energy cost of ~84kWh/1,000kg.

According to the NIST document below:
Bond Dissociation Energies in Simple Molecules

The energy cost associated with breaking one of the double-bonds between Carbon and one of the two Oxygen atoms in a CO2 molecule is 532.2kJ/mol, which yields Carbon Monoxide and an Oxygen atom.

I recall very little of my basic chemistry, so take what follows with a truck load of salt.

CO2 Molar Mass: 44.01g/mol
CO Molar Mass: 28.01g/mol
1kg of CO2 is 22.72 mol
1kg of CO is 35.70 mol

17.85 moles of CO2 is required to obtain 1kg of CO.

We need 27,301kg / 974,645.7 moles of CO, so we need 620,309.6 moles / 27,302.4kg of CO2.

620,309.6 mol of CO2 * 532,200J/mol = 330,128,769,120J / 91,702,436Wh of dissociation energy for 27,301kg of CO

84,000Wh/t for CO2 liquefaction * 27.302t = 2,293,368Wh of energy to obtain LCO2 from atmospheric CO2

From 298.15K we must remove ~191.5kJ/kg of LOX, so 3,882,279,500J / 1,078,411Wh for 20,273kg of LOX.

From 298.15K we must remove ~225.15kJ/kg of LCO, so 6,086,029,650J / 1,690,564Wh for 27,031kg of LCO.

Carnot efficiency of modern heat pumps is about 0.5, so 2,156,822Wh to liquefy 20,273kg of O2 and 3,381,128Wh to liquefy 27,031kg of CO.

This presumes we start the liquefaction process at room temperature. Thermal dissociation of CO from CO2 typically occurs around 700C, but there are also room temperature methods involving catalysts, which is what we'd likely use in a practical Mars ISRU system to split CO2.

Energy Inputs Summary:
2,293,368Wh to obtain 27,302kg of LCO2
91,702,436Wh using a thermal dissociation method (our fallback if the room temp catalyst doesn't last long enough)
2,156,822Wh for liquefaction of 20,273kg of O2
3,381,128Wh for liquefaction of 27,031kg of CO

99,533,754Wh of total input energy to obtain 47,304kg of LOX/LCO propellant for a 6 person MAV.

Even if we had to double the input energy requirement, we're not talking about that much additional energy. Over the course of 365 days, 99,533,754Wh works out to a constant input power of 11,362.3 Watts. That's roughly what a 10kWe KiloPower fission reactor delivers. I'm generally in favor of "the nuclear option" because we only need to dig a hole, place the reactor in the hole, connect the power cable, remotely command the withdrawal of its singular control rod, and then leave it the hell alone while it delivers the power.

Since the western world seems very anti-nuclear right now, we do have an alternative. It's more complex than the nuclear option because it operates intermittently and is subject to diurnal cycles / seasonality / dust storms, but it could still work for an exploration class mission where money is no object. My personal contention is that we should take both options, in case one or the other fails. The most significant penalty is the increased weight associated with a battery subsystem to store and buffer the power being generated, into the ISRU equipment. This solution won't scale-up very well to provide power to a colony, unless made from ISRU materials. That matters less here where we're conducting a science experiment in the name of "pushing boundaries", and the personnel undertaking the mission have already volunteered to be human guinea pigs for science's sake.

In the summer time, in an equatorial region of Mars, we get about 586W/m^2 for 6 hours per day. There will be some power produced outside of peak hours, which ought to be used to top-up the battery to keep it warm at night. We have 29.5% BOL efficiency triple-junction photovoltaics provided by Northrop-Grumman (previously Orbital ATK). Some of the newest cells are better than this, but 29.5% efficient cells are legacy tech with flight heritage in the actual environment where they will be used. In other words, it's proven to work across multiple missions, and we like things that have exhaustive testing and real world use to their credit. The integrated system is better known as the MegaFlex foldable / deployable photovoltaic array. MegaFlex was successfully used to power our Mars InSight Lander.

That means we should expect to convert 172.87Wh/m^2 * 6hrs = 1,037.22Wh per day under "full Sun" conditions on the surface of Mars. 250m^2 of array surface area therefore nets 259,305Wh per day, so we can make the LOX/LCO propellant over roughly 384 days under ideal power generating conditions. Our surface stay is almost 2 years, so we have some buffer to work with if things don't go precisely to plan.

Methane is a better rocket fuel than Carbon Monoxide, especially as the Delta-V requirement increases, but 100MWh per year is not asking for an inordinate amount of power. The technological hurdle to clear for an atmospheric-only ISPP solution set is far lower than it is for Methane production, which includes a Sabatier reactor and shallow surface mining machines to scoop up Martian regolith and extract whatever water it contains. We should locate a good water supply first, and then figure out how much equipment and money is required to convert that water into rocket fuel. Even if we can do that without undue effort, I will opine that washing, cooking, cleaning, and flushing are higher priorities than obtaining premium rocket fuels when a cheaper / easier to produce fuel is available.

Exploration mission 2 or 3 should introduce the Sabatier reactor and mining equipment. The first mission should simply prove that we can do atmospheric ISPP and extract as well as purify usable quantities of liquid water from the frozen Martian regolith. It's probable that the additional power and equipment mass required to make Methane is not energy or mass favorable. Liquid CO2 is easy to get, whereas liquid water is not. Whatever water a Mars colony does get is going to have a rather lengthy list of higher priority uses.

Here on Earth, apart from electric power generation, Methane is the base stock for modern synthetic lubricants, plastics and rubbers, synthetic fibers, refrigerants, and industrial chemicals such as solvents. The Hydrogen in water will also be required to make Sulfuric acid. Mars has abundant surface deposits of Sulfur, and Sulfuric acid is the basis of most industrial chemical processes. Even if Mars has Methane reservoirs buried in the ground, those "other uses" are more essential to colonization efforts than rocket fuel. We're setting up an entire human civilization from scratch, from the starting point of relative energy poverty since absolutely nothing is "human ready" on Mars. Therefore, economizing on energy and materials inputs, even for rocket fuel, is essential.

kbd512 · Not So Free Chat

Void,

We should certainly look into using geothermal power for thermal fuel conversion processes. Generating power directly may produce undesirable side-effects. Messing with the heat flows within the Earth's mantle is not something we want to experiment with. There's a major difference between pumping a batch of Carbon and Hydrogen down a bore hole and letting it "cook" within the upper mantle vs drawing the heat out of the mantle for electric power generation.

We already have lots of labor-saving machines. Whether or not AI-enabled humanoid robots add new capabilities remains to be seen. I think the idea has a lot of potential, but the real question is how much will those robots cost, how autonomous are they when it comes to critical job functions, and how much energy will making and using them require?

I don't have answers to any of those questions. If such an automaton truly does cost about $25K, as Elon Musk suggests, provides a like-kind substitute for repetitive manual labor, and lasts for 10 years before it's worn out, then it's a technological windfall. Quite a few hard labor jobs would benefit immensely from robotic workers that cannot be injured or killed. However, there's a high probability that these robots cost a lot more and take a lot longer to develop than anyone initially thought. Self-driving cars are an example that immediately comes to mind. At the present time, there are no self-driving cars. There are a few that can operate semi-autonomously. They've always been "just" 2 to 5 years away, sort of like the hype surrounding "better batteries".

kbd512 · Science, Technology, and Astronomy

tahanson43206,

Apologies for missing the meeting. I meant to send out an update. It's Mother's Day today and I took my wife out on a date.

kbd512 · Not So Free Chat

Void,

It's more along the lines of, the "flywheel effect" of large masses of spinning metal absorbs the minute frequency fluctuations and buys time to either bring additional generating capacity online or to shut it down. When nearly all of the grid was run that way, it was difficult to either drag the entire grid down or have power surges as loads dropped.

I would very much like a viable alternative to depleting coal, oil, and gas, but at the present time the most viable alternative seems to be using input electrical or thermal power to synthesize storable fuels from atmospheric or ocean-derived CO2 and Hydrogen, and to run the grid using on-demand energy turbine-based generators. That implies some combination of solar thermal, nuclear thermal, and hydrocarbon fueled gas turbines that preclude having to spend an enormous amount of energy and materials on grid upgrades and massive energy stores with very low energy density and high loss rates.

Professor Michaux's suggestion of building energy consuming machines that are not entirely dependent upon precise frequency control is another viable alternative. This would entail high-voltage DC machines that don't require the use power electronics to perform energy conversions, such as DC-to-AC-to-DC.

I'm agnostic on the ultimate solution, provided it works in the real world, and we're not constantly fed a bunch of ideological pablum about the failures (the typical "don't believe your lying eyes" silliness) and obfuscation about the underlying reasons behind those failures. I can even accept some mistakes while we figure out why something fundamentally new does or doesn't work, but only if we're actively learning from our mistakes and don't double-down on demonstrated failures. Whatever happened in Spain needs to become one of those "teachable moments" where ideology ends, accountability begins, and course correction takes place.

kbd512 · Not So Free Chat

Void,

The people who run China have caused the greatest total number of civilian deaths in the 20th century. Any government that wantonly and callously kills the very people who ultimately determine the fate of their nation is dictionary definition "stoopid". Making photovoltaic panels using coal that is otherwise too expensive to economically mine and slave laborers is ruthless and/or desperate beyond reason. Any nation that "conquers" China shall inherit a toxic waste dump filled with people too ruthless and/or desperate to make better decisions about how to power their nation. That seems like a terrible investment. Even if the Chinese government simply handed the nation over to us and said, "we give up, you fix it", I would be exceedingly reluctant to even attempt to clean up the mess they've made.

That said...

Let's enter a world of modest make-believe where photovoltaics (PV) and wind turbines cost nothing to make, require no energy (green or otherwise), nor any labor to make. We wave our magic wand and they simply materialize before us. In this same world where "magic" allows us to conjure-up PV panels and wind turbines from nothingness, all other components of an energy grid cost real money. In this world where our special little wand produces PV and wind turbines, the materials to produce all other goods and services still require energy / labor / capital inputs.

In this world of modest make-believe, physics still applies to every other aspect of energy generation and usage. Therefore, staggering quantities of Lithium-ion batteries are necessary to prevent vertical power drops measured in gigawatts, which is what happened to the Spanish power grid. These batteries still cost what they cost, still require materials / energy / labor / capital to produce, and we still have a very modest partial recycling solution attempting to recover the scarce metals from them when they eventually quit working, which is always 5 to 10 years away. In rough general terms, 10% of the energy that any battery can store over its lifetime is required to make them. We can always wave our wand to create more PV panels, but that's the extent of what we get. We still have to install them, take care of them, buffer the power they create, etc.

The recent Spanish grid technology failure highlighted what will happen whenever electronics fail to do what spinning metal does. I recently watched a podcast with an energy expert from the UK, who was talking to someone from America about where Colorado's energy grid is headed- the same ever-precarious position Spain's electric grid presently occupies. The synchronous condensers could not prevent Spain's grid collapse. What the Spanish electric grid really needed was "fast storage", something only electro-chemical batteries or super capacitors can provide.

Battery Energy Storage Systems (BESS) must be sized according to the demonstrated requirement. If a grid was primarily wind-powered and 2 week long wind doldrums were encountered with regularity, as they are, then we'd have to increase generating capacity to the point of absurdity, which also increases the cost of the grid upgrades to the point of absurdity, or else store energy sufficient to cover the periods of time when wind power generation drops to near-zero, in order to prevent a grid collapse. Here in America we burn natural gas or coal to cover those periods at the present time, which should be added to the cost of any photovoltaic (PV) or wind turbine energy generating solutions since no grid remains functional for 24 hours without them. If you "overbuild" PV or wind turbines, then you add about $1 per Watt for grid upgrades for every Watt of overbuild. This is mostly beefed-up voltage transformers and power lines, but the nameplate capacity of the Spanish PV and wind turbines is already far above their peak consumption, much as it is in Germany.

A 14-day / 2.2TWh battery sufficient to cover Colorado's energy requirements, based on Colorado's 2023 net generation of 57.5TWh, at $0.148/Wh, would cost $326B every 10 years, or about $2.45T over 75 years. 10X 1GWe nuclear reactors would cost $220B ($10B per reactor for construction, $1B for 50X fresh batches of fuel, $1B for maintenance, $10B for decommissioning / loan repayment interest / unanticipated costs) over 75 years. The entire lifecycle cost of 10 reactors is less than the initial purchase price for the first of 8 suitably large BESS. Even if BESS installed cost falls to half of what it presently is, BESS does not generate any energy, it only consumes energy, so the BESS cost is in addition to the cost of PV and/or wind turbines. If we primarily use PV, then we need a much larger BESS to cover seasonality. Pumped hydro works out to about the same cost as BESS due to losses and poor energy density, but is unable to respond rapidly enough to be of great utility as a PV or wind turbine backup, unless all power is buffered through the hydro reservoirs, in which case losses purely due to friction will be horrendous. Energy production and immediate consumption always beats storage in terms of total cost. That logical maxim is even true of hydrocarbon fuels. If you had to store much in the way of natural gas prior to feeding it into a gas turbine, your energy costs skyrocket.

Whenever equivalent hour-by-hour generation and grid stability are required, PV and wind turbines rapidly become the most expensive forms of generation as their percentage of a grid's energy mix increases, which is always reflected in electricity costs to rate payers. If any of the cost claims about PV and wind turbines were actually true, then at some point rate payers would pay less money than they do for pure coal or natural gas electricity generation, yet they never do. It's pretty obvious why they don't. A series of very costly grid upgrades, complete backup power plants, and/or battery storage are required.

This is why the vast majority of grid operators refuse to install grid storage batteries, to include Colorado, whose directors have publicly stated that they will not use BESS to any significant degree, citing cost and performance as the primary reasons not to use BESS.

If we scale-up a similar BESS to power the US during a 14 day wind doldrum, then it's 165TWh and $24.4T, every 10 years. US GDP for 1 year is about $25T to $30T. I'm not the world's foremost economist, but I don't think any nation can afford to devote 2 out of every 10 years of GDP to storing energy in batteries, merely to appease someone's "green energy" fantasies. If we primarily use PV, then we need a 28 day 330TWh battery. These devices would be scattered across the US, obviously, but the total storage capacity to deal with wind doldrums or seasonality doesn't "go away" without using that magic wand that we seem to have misplaced. This kind of energy cost should make it abundantly clear why we're unlikely to ever build a 165TWh to 330TWh battery within our lifetimes. If we bring back most of that pure Platinum asteroid to Earth as repayment, then maybe there's enough hard currency to cover the initial construction costs, but what about cost over time? What about the fact that 10% of the energy that the battery can discharge over time is required to make it? At some point, economy actually means "energy economy" (energy input to useful economic output ratio).

A sCO2 gas turbine can respond very rapidly to load and supply changes, but not in 1 second. The entire Spanish grid failure was complete in 5 seconds. Contrary to initial reporting, it was indeed a complete failure. All generation of all types briefly tripped offline to protect the grid from the energy that had nowhere to go. The power inverters and synchronous condensers couldn't respond fast enough to deal with the frequency and power throughput fluctuations. There was no issue whatsoever with the PV providing the input power demanded by the grid. The voltage and amperage supplied were more than sufficient. It had everything to do with dynamic power redirection on the grid destabilizing it to the point that the grid's only option was to disconnect the power supply to prevent irreparable damage to grid-connected equipment like transformers and peoples' personal electronics. The moral of the story? You need "fast storage". It's not optional. At a national level, you need power run through a power buffer (an electro-chemical battery bank). You cannot "blow harder" and solve this problem. The more PV and wind you have on your grid, the larger the power buffer needs to be so that second-by-second disturbances to grid frequency doesn't drag the entire grid down with it.

This is why predominantly PV and wind turbine electric grids are likely to remain a pipe dream unless sufficient fast storage is included. If what we're actually doing is pretending to quit using hydrocarbon fuels while doing nothing of the sort, then we should stop playing that valueless game. You have to descend into a fantasy world where you can ignore energy consumption economics and the practical aspects of running a stable grid for it to work. We have a lot of fairly solid tech that works acceptably well most of the time. We do not have a magic wand, nor anything close enough to a magic wand, and likely never will. The cost to procure sufficient batteries as a grid-stabilizing power buffer is what kills this PV and wind turbine electric grid fantasy. That takes us right back to thermal systems. Maybe all those electrical engineers who came before us weren't so primitive and limited in knowledge after all. Maybe they built the grid the way they did through hard-won experience, aka "the school of hard knocks".

kbd512 · Single Stage To Orbit

Dr Clark,

Tim Chen (Chief Engineer for Boeing Satellite Systems) seems to think SSTO with LOX/RP1 is impossible and SSTO with LOX/LH2 is possible but very difficult. I want to understand why that is, because there seems to be an absolute fixation on the marginal Isp differences between RP1 and LH2. The combination of Total Impulse (Total Force) generated to accelerate a vehicle with a constrained mass is what dictates whether or not that vehicle attains orbital velocity, or doesn't. You get marginally better Isp with LOX/LH2 at the expense of much larger propellant tank structures that add to SMF and detract from PMF. Materials don't get any stronger as vehicle volume increases. On top of that problem, LH2-fueled engines produce less than half as much thrust per unit engine mass, as compared to LCH4/RP1-fueled engines. Modern hydrocarbon fueled rocket engines (Merlin-1D, Raptor-3; 185:1 to 190:1 TWR), about 2.5X as much thrust per unit engine mass as LH2-fueled engines (RS-25D, J-2X, RS-68A; 47:1 to 75:1 TWR).

I can see why they think this is impossible. They act as if a LH2-fueled vehicle with more than double the internal volume of an equivalent RP1 fueled vehicle will somehow generate meaningfully more total force for a given propellant mass, but the actual mass differential due to poor vehicle acceleration (fighting gravity) and added drag makes the vehicle's mass (and thus Isp) differential trivial by the time we scale-up the PMF to a Space Shuttle mass equivalent.

My operating assumptions are that for practical SSTOs, we require structural fibers with the strength of T1200 and engines with 200:1 thrust-to-weight ratios, so as to keep SMF low and TWR high enough for the vehicle to deliver useful PMF.

Please tell me if you find any serious flaws in the figures I've presented below:

Using 90% of vacuum Isp, you get 304.2s for RP-1 (RD-180), 324.9s for LCH4 (Raptor 3; sea level model), and 382.5s for LH2 (RS-25). LH2 is clearly better than RP1 on Isp, but that figure of merit is highly misleading without understanding just how much Density Impulse affects Total Impulse for a given vehicle / structural mass fraction (SMF), by way of its propellant tank structure, and how high engine TWR is required for any SSTO concept to succeed.

Oxidizer: 2,339.2kg (1.746m^3 of LOX at 1,340kg/m^3)
Fuel: 860kg (1m^3 of RP1)
Total Propellant Volume: 2.746m^3
Engine: RD-180
Mixture Ratio: 2.72:1
Mass Flow Rate: 1,250kg/s
Thrust: 3,723,161N / 379,657kg-f (90% of vacuum thrust)
Firing Time: 2.55936s
Total Impulse from 1m^3 of fuel: 9,528,909N-s
Propellant Mass for 510s of Firing Time: 637,500kg; 1,899MN-s Total Impulse
LOX/RP1 Propellant Mixture Ratio and Total Propellant Mass and Volume for 510s of Firing Time:
1,250kg/s * (2.72/3.72) = 913.978494623655914kg/s LOX; 1,250kg/s * (1/3.72) = 336.021505376344086 RP1
466,129kg / 347.857m^3 LOX; 171,371kg / 199.269m^3 RP1; 547.126m^3 ttl propellant vol

Oxidizer: 1,606.64kg (1.2m^3 of LOX at 1,340kg/m^3)
Fuel: 422.8kg (1m^3 of LCH4)
Total Propellant Volume: 2.2m^3
Engine: Raptor 3
Mixture Ratio: 3.8:1
Mass Flow Rate: 1,160kg/s
Thrust: 2,471,276N / kg-f of thrust (90% of vacuum thrust for sea level nozzle)
Firing Time: 1.74952s
Total Impulse from 1m^3 of fuel: 4,323,540N-s
Tank Volume for RP1 Equivalent Total Impulse: 4.849m^3 (77% increase over RP1)
Propellant Mass for 510s of Firing Time: 591,600kg (92.8% of RP1); 1,260MN-s Total Impulse (66.4% of RP1)
LOX/LCH4 Propellant Mixture Ratio and Total Propellant Mass and Volume for 510s of Firing Time:
1,160kg/s * (3.8/4.8) = 918.333333333333333kg/s LOX; 1,160kg/s * (1/4.8) = 241.666666666666667kg/s LCH4
468,350kg / 349.515m^3 LOX; 123,250kg / 291.509m^3 LCH4; 641.024m^3 ttl propellant vol; 17.2% vol increase over RP1)

Oxidizer: 425.4kg (0.317m^3 LOX at 1,340kg/m^3)
Fuel: 70.9kg (1m^3 of LH2)
Total Propellant Volume: 1.317m^3
Engine: RS-25
Mixture Ratio: 6:1
Mass Flow Rate: 514.49kg/s
Thrust: 2,050,942N / 209,138kg-f of thrust (90% of vacuum thrust)
Firing Time: 0.96464s of firing time
Total Impulse from 1m^3 of fuel: 1,978,421N-s
Tank Volume for RP1 Equivalent Total Impulse: 4.816m^3 (75% increase)
Propellant Mass for 510 Seconds Firing Time: 262,390kg (41.2% of RP1); 1,046MN-s Total Impulse (55.1% of RP1)
LOX/LH2 Propellant Mixture Ratio and Total Propellant Mass and Volume for 510s of Firing Time:
514.49kg/s * (6/7) = 440.991428571428571kg/s LOX; 514.49kg/s * (1/7) = 73.498571428571429kg/s LH2
224,906kg / 167.840m^3 LOX; 37,484kg / 528.692m^3 LH2; 696.532m^3 ttl propellant vol; 27.3% vol increase over RP1)

Implications:
To deliver the same 1,898,812,110N-s (1,899MN-s) Total Impulse that LOX/RP1 delivers by firing for 510s:
Raptor 3 has to fire for 768s, which implies 705,280kg (526.328m^3) of LOX, 185,600kg (438.978m^3) of LCH4, 891,289kg (965.306m^3) in total
RS-25 has to fire for 926s, which implies 338,681kg (242.747m^3) of LOX, 56,447kg (796.148m^3) of LH2, 476,327kg (1,038.895m^3) in total

The typical response, "I'll just add more engines" doesn't work here. You increase the vehicle's SMF the moment you do that. The only valid response would be to double the TWR of the LH2-fueled engine, which we cannot seem to do. IF you could actually do that, then what's stopping you from proportionally increasing the TWR of RP1-fueled engines? The only methods we have for doing that at this point (reducing engine weight by using advanced materials and design simplification), are broadly applicable to any chemical rocket engine. For a SSTO vehicle, you cannot overcome a force-generating deficiency merely by adding more engine weight. At some point, you must improve TWR. The TWR for the RP1 and LCH4 engines is already sufficient. LH2 engines need dramatic TWR improvements.

You may or may not need to deliver 1,899MN-s to push any particular payload into orbit using lighter / higher-Isp propellants, but if that's how much force you require to deliver a heavy payload to orbit, then your propellant volume increases for equivalent total force generated, by 76.4% for LCH4 or 89.9% for LH2.

Space Shuttle Main Engines typically fired for about 520s. I used 510s, which is close enough to what I could recall from memory. Using 90% of vacuum Isp, Total Impulse equates to 1,066,489,840N-s over 520 seconds, so 3 RS-25 engines would deliver 3,199,469,520N-s. The pair of Solid Rocket Boosters delivered about 3,309,476,870N-s. All together, 6,508,946,390N-s of thrust was required to deliver a 116,120kg Space Shuttle Orbiter to LEO. Space Shuttle consumed approximately 997,904kg of APCP plus 735,601kg of LOX/LH2 to achieve orbit, 1,733,505kg in total, which is pretty darn close to LOX/RP1.

How much of each liquid bi-propellant combination do I need to generate 6,508,946,390N-s of thrust using real world engine designs?

LOX/RP1: 1,597,846kg (1,192.422m^3) of LOX; 587,443kg (683.074m^3) of RP1; 2,185,289kg (1,875.496m^3)
LOX/LCH4: 2,418,744kg (1,805.032m^3) of LOX; 636,511kg (1,505.467m^3) of LCH4; 3,055,255kg (3,310.499m^3; 177% of LOX/RP1)
LOX/LH2: 1,399,547kg (1,044.438m^3) of LOX; 233,258kg (3,289.956m^3) of LH2; 1,632,805kg (4,334.394m^3; 231% of LOX/RP1)

The propellant mass differential between LOX/RP1 and LOX/LH2 is only 552,484kg in favor of LOX/LH2 for equivalent Total Impulse, so a 33% propellant mass increase crammed into 2.3X LESS volume. The LOX tank for a RP1 fueled vehicle is 14% larger while its fuel tank is 4.8X smaller than an equivalent LH2 tank. A 43% propellant volume reduction is likely to have an outsized effect on SMF, as we're about to see.

Will that 552t of additional propellant mass for LOX/RP1 over LOX/LH2 make an actual difference to payload mass for a SSTO?

For a SSTO, the driving forces behind vehicle SMF / dry mass fraction are engine TWR and propellant tank volume and hoop stress from internal pressurization, not aero loads or acceleration loads. NASA's Composite Cryo-Tank Demonstrator Program already proved that the internal pressurization load required by the LH2 tank drove the minimum structural mass requirement, rather than the much higher mass of the LOX in the associated LOX tank, so long as vehicle acceleration was limited to 3g, as it was for the Space Shuttle. LH2 propellant tanks require the highest internal pressurization levels and are physically the largest in size across all common fuels, so this internal load problem is worse than it superficially appears to be, but let's hand-wave that for now.

We have a constrained mass-to-orbit to work with, of 116,120kg, which is equal to the Space Shuttle's max liftoff mass. This is where the pitiful TWR of the RS-25 absolutely kills our LH2-fueled SSTO concept, especially for full reusability. We need 14X RS-25s for a 1.5:1 liftoff TWR, which adds 44,478kg of engine mass to our vehicle. Unfortunately, our total mass-to-orbit won't change to accomodate that low TWR. 38% of our total mass-to-orbit cannot be the engines! We get 17,261kg as the equivalent engine mass for 200:1 TWR LOX/RP1 engines, for the same 1.5X liftoff TWR. We get 20,658kg as the propellant tank mass for LOX/LH2. That takes our SMF, for engines and propellant tanks only, up to 56% of our total PMF, for the LH2 SSTO concept. Stick a fork in that LH2 SSTO concept, because it's done! We only have 50,984kg remaining for the LH2 SSTO's heat shield, life support systems, and useful payload. We still have 72,767kg to work with after accounting for the propellant tanks, engines, and heat shielding for the RP1 SSTO concept.

The remaining PMF for a RP1 SSTO, after engine and propellant tank mass are accounted for (89,916kg / 2,185,289kg = 0.039), is 1% higher than the LH2 SSTO payload mass (50,984kg / 1,748,925kg = 0.029). Fixating on Isp, when we're discussing a practical SSTO that will be powered by RP1 or LCH4 or LH2, is an utter waste of time. Total mass to orbit is the same 116,120kg. The higher propellant mass of the RP1 SSTO gets converted into additional thrust, with the end result that usable PMF is slightly better than it is for LH2 fueled design.

The Space Shuttle Orbiter's internal volume, excluding engines and control surfaces, was about 965m^3 and total surface area was about 1,105m^2. Therefore, a SSTO Space Shuttle's internal volume for propellant is about 1.95X that of the historical Space Shuttle Orbiter when powered by LOX/RP1, 3.43X larger in terms of internal volume when powered by LOX/LCH4, or 4.49X larger when powered by LOX/LH2.

Rockwell's VTHL SSTO concept was to be powered by LOX/LH2 only, have roughly the same payload as the ultimate Space Shuttle design, so it was substantially larger than the historical Space Shuttle Orbiter as a result. They were overly-optimistic about dramatic LH2 engine TWR improvements that never materialized. The only major differences between the various Space Shuttle vehicle designs relate to how large the vehicle volume becomes and its GLOW. At this scale, a 1,000t increase in GLOW is far less concerning than a doubling of internal vehicle volume and/or surface area. My basic assertion is that the vehicle has to remain as small as possible because materials don't get any stronger or lighter or more heat-resistant as you scale-up the total internal volume and surface area. The historical Space Shuttle's GLOW was 2,029,633kg. The GLOW for my RP1 SSTO Space Shuttle concept is only 271,776kg greater.

200:1 TWR RP1 fueled engines, for a 2,301,409kg GLOW and 1.5:1 liftoff TWR, would weigh 17,261kg
185:1 TWR LCH4 fueled engines, for a 3,171,375kg GLOW and 1.5:1 liftoff TWR, would weigh 25,714kg
75:1 TWR LH2 fueled engines, for a 1,748,925 GLOW and 1.5:1 liftoff TWR, would weigh 34,979kg

Lockheed-Martin's externally box-stiffened 10m diameter composite cryogenic tank demonstrator had an internal volume of 634.297m^3 and a weight of 2,981kg, so 3 of them, sufficient to hold 1,875.496m^3 of LOX/RP1 propellant, would weigh 8,943kg. It was made with IM7 fiber (820ksi tensile strength) vs Toray T1200 fiber (1,160ksi tensile strength), a 41.5% strength improvement. I specify a stronger fiber for even more strength, not less weight.

116,120kg - 8,943kg (propellant tanks)- 17,261kg (engines) - 17,149kg (heat shield) = 72,767kg remaining (for the landing gear, pressurized cabin, payload- passengers or cargo)

The 17,149kg heat shield mass figure represents the historical Space Shuttle Orbiter's heat shield weight multiplied by 2. I presume lighter and more protective modern heat shielding materials will allow us to constrain the heat shielding mass to this value.

If we remain fixated on using LH2, then most of the mass that we actually deliver to orbit is engines, propellant tanks, and heat shields.

kbd512 · Not So Free Chat

RobertDyck,

I watched the video recording wherein Mayor Ras Baraka and his entourage attempted to break into an ICE detention facility (a federal prison by any other name) through a side gate entrance, whereupon they were summarily arrested.

I can't speak to the veracity of claims made by a website, but when interacting with the US federal government, this is my advice:

NEVER ATTEMPT TO BREAK INTO US FEDERAL PRISONS, COURT HOUSES, OR MILITARY BASES!

My advice based upon first-hand working knowledge and experience as a former member of the US federal government who was routinely assigned guard duty. If you choose to ignore my advice, then federal agents charged with defending those facilities will arrest you. It doesn't matter if you're the Mayor, the Governor, a state or federal Senator, an accredited member of the free press, or even a General Officer who is employed by the US federal government.

kbd512 · Not So Free Chat

Calliban,

Shale oil is excellent for making gasoline or lighter products. Gasoline is the most consumed refined petroleum product in the US, by a wide margin. Heavier products can be made with shale oil and coal, if necessary. America has 469 billion short tons of coal reserves. We already make most of our plastics, synthetic fibers, and lubricants from natural gas. Venezuela has at least 303 billion barrels of proven heavy crude reserves if other countries need that, but America should focus on light sweet crude and synthetic fuels production. At Venezuela's present extraction rate of 392,000bpd, their crude oil reserves should last for another 2,117 years.

We have General Motors LS platform engines that produce 1,000lb-ft of torque at 3,000rpm (571hp), running on LPG. That is a diesel-equivalent spark-ignited engine that weighs a fraction of what a typical Cummins / Caterpillar / NaviStar / Detroit Diesel semi-truck engine weighs. LS engines have a well-established reputation for durability. The Dart-branded LSNext iron block platform is more than capable of withstanding the power applied, as are the new LT iron blocks. I'm less certain about some of the new Aluminum blocks, but presumably those could work as well. Said engine was produced for a Spanish customer to meet emissions requirements that European-sourced diesels were unable to meet. Ka-Tech's LPG engine costs more than the mass-produced engines coming out of GM's Tonawanda plant, but it's not as expensive as any of the typical diesel truck engines and uses far less material. Even if it only lasts for 200,000 miles, it's far easier to completely remove from a semi-truck's frame to rebuild, so total ownership cost will be lower over time as a result.

Now that geared CVTs exist to always keep an engine in its optimal power band, I can see light hydrocarbon engines using gasoline or LPG as a "good enough" substitute for those giant diesel engines while still delivering diesel-like performance. If Ka-Tech's engine makes about 800lb-ft of torque at 1,800rpm, then it can cruise down a highway at the same rpm as much larger diesel engines from about 25 years ago while making the same power. In the early 2000s, the common semi-truck engines of that era would run near 1,500 to 1,800rpm at highway speeds. It's not ideal, obviously, but good enough.

A 15L displacement Cummins ISX 485 diesel makes 1,650lb-ft of torque at 1,200rpm, 485hp at 2,100rpm, and weighs 3,021lbs. They require just as many engine control electronics as any modern spark-ignited engine to do that. Go back about 25 years and look at the torque and power figures of the mechanical diesels, and Ka-Tech's LS engine closely resembles the performance of the last generation of mechanical diesel engines. The Ka-Tech engine doesn't have half as much displacement, weighs around 600lbs, and is small enough that it could be stuffed under the cab between the frame rails. That is wildly impressive.

All the weight savings on the nose of the chassis means these re-engined semis won't be overloaded to the point where the steering tires are approaching their structural integrity limit. Maintaining air pressure in the front tires at precisely the right value will be less of a factor in whether or not the truck blows a tire. This overload condition has become an issue over time as the front tires of semi-trucks are forced to bear more weight from heavier diesel engines. The weight saved can either be deleted or used to beef-up the frame rails to the point that they don't become bent / tweaked as often from hitting potholes.

All that is to say that I think we now have acceptable solutions for repowering semi-trucks and boats with smaller / lighter / cleaner / more powerful engines, even though it's doubtful that they'll last as long in service as the current generation of much larger and heavier diesel engines. Even so, the LS engine is something you can repair in a small shop using hand tools. An overhead gantry crane and massive tools are only required for large diesels. Cummins ISX series engines are only anticipated to go 350,000 to 500,000 miles between overhauls, because that extra power at a much lower rpm shortens their service lives as well. A complete ISX series engine overhaul runs about $30,000. A full custom LS engine with all the best parts can be had for that amount of money.

These newer / lighter / more powerful engines tend to last a long time as long as you run the engine hard every day and change the oil frequently. The vehicle itself will fall apart around an otherwise fully functional engine. Idling and low-rpm operation absolutely kills these newer engines, which were deliberately designed to deliver race car performance on a daily basis. We've made ordinary passenger vehicle engines behave a lot like aircraft engines- the worst possible thing you could do to negatively affect their longevity is to let them loaf along or use them infrequently. Our Lithium-ion batteries function the same way- use them every day and they're fine. If you stop using them or change their charge / discharge behavior, they quit functioning in short order.

kbd512 · Science, Technology, and Astronomy

Slate Auto EV Truck / SUV

Edit #2 (vehicle interior):

Edit #1 (overhead shot of the Warsaw, Indiana manufacturing facility):

Slate is set to offer EV trucks and SUVs without superfluous electronic gadgetry that drives up the price of manufacturing and maintenance. They have manual roll-up windows, no radios / infotainment systems, all federally mandated safety features, to include a backup camera, and are projected to cost $20,000 with subsidies or $27,000 to $28,000 without subsidies. Slate is opening a repurposed 1,400,000ft^2 manufacturing facility in Warsaw, Indiana, with first deliveries projected for 2027. Jeff Bezos is backing this venture.

Slate uses plastic bodies so there is no painting and less rusting on salted winter roads. No gigantic sheet metal stamping presses or painting booths are required. The vehicle comes in slate gray only, with colored plastic body wraps applied to personalize vehicles. They will have 150 to 240 miles of range. The Slate truck model (all models are based upon the same chassis) with 150 miles of range has a curb weight of 3,602lbs. Size-wise, said truck is in the same class as the ever-popular Ford Ranger. That makes this vehicle very "normal" in terms of size and weight, meaning not ridiculously overweight when compared to a gasoline or diesel engine vehicle of similar dimensions. Max bed payload is 1,433lbs and max tow payload is 1,000lbs.

Slate's truck captures the essence of what an EV was always supposed to be- a simpler / more robust / more reliable machine than an internal combustion engine vehicle with a range suitable for 95% of all real-world driving. It's not a like-kind replacement for a gasoline or diesel engine truck, but for what most people use their vehicles for most of the time, it doesn't have to be, either. Provided that Slate comes close enough to their projected MSRP, I would be willing to bet that their trucks sell like hot cakes.

kbd512 · Not So Free Chat

Further research into this topic reveals that one of the publicly proposed solutions for Spain's electric grid stability issues is connecting photovoltaic and wind turbine farms to massive flywheels (electric motor-generators) to simulate the grid frequency stability that inverter-based photovoltaics and wind turbines cannot provide.

Tahanson43206 posed this very question to me during our Sunday meeting about what solution I would pursue to address this issue. My own proposal now appears to be in good agreement with what professional electrical engineers (something I am not) have offered up as a possible solution.

A second proposed solution, which I think is highly impractical and likely to be inordinately expensive, is to convert all the grid-attached electricity consuming devices to use DC power. While this proposal would entirely eliminate the frequency control problem, I'm not clear on how this would fix the load-following problem. A slew of electrical equipment changes would be required to implement this solution.

Mostly, I think photovoltaics and wind turbines are non-solutions to energy problems at the city level or above. There is quite literally no such thing as a photovoltaic or wind turbine grid energy solution that can reliably deliver electrical power, 24/7/365. Multiple complete backup energy generating devices have to be maintained to support this Rube Goldberg "green energy" non-solution.

How Much Money Does 1 acre of Solar Panels Make?

From the article:

...
How many solar panel per acre
The number of solar panels that can fit in one acre depends on several factors, including the size and the tilt and orientation of the panel array, and any space required for access roads, fencing, and other infrastructure.
An acre of land is equivalent to 43,560 square feet. By converting the panel dimensions to square feet, we can calculate the number of panels that can fit within an acre.
For example, a 540-watt solar panel with dimensions of 2279×1134×35mm occupies approximately 27.82 square feet. Assuming no space is required for access roads or other infrastructure and that the panels are mounted in a fixed tilt orientation, approximately 1,565 solar panels can fit on one acre of land.
Note:
In reality, space is usually required for access roads and other infrastructure, and the orientation of the panels may be adjusted to maximize their efficiency. Therefore, the actual number of solar panels that can fit in one acre may be lower.
...
Solar farm income per acre
The annual income from one acre of solar panels varies based on several factors, including location, sunlight availability, tax credit for solar photovoltaics, and the efficiency of the panels.
Based on previous calculations showing a monthly solar power production of 126,765 kWh, we can estimate the income from a solar farm using the PTC valued at 2.75¢/kWh, according to information from Energy Department. The solar farm income is $3,486.04 per acre per month and $41,832.48 per acre per year.

The cost to install a utility-scale solar farm in Texas can vary, but a reasonable estimate is between $400,000 and $680,000 per acre. This includes the cost of materials, installation, and other related expenses. A one-acre solar farm can produce approximately 0.5 megawatts (or 500,000 watts).

$680,000 / $41,832.48 = 16.26 years (assumes the bank will issue a loan without interest, which will not happen)

I'm going with the higher rate per acre because there are all manner of licensing / operating fees paid by any certified grid-connected utility scale service provider responsible for equipment purchase, installation labor for the solar farm and grid connection, and maintaining their equipment. If they don't allocate some additional capital to deal with contingencies, they'll likely go bankrupt. This ought to illustrate the impossibility of $0.02/kWh being an actual rate paid by an electric power consumer who opts to use photovoltaics. The math doesn't add up at a fundamental level (equipment purchase / installation loan plus loan interest). 20 year loans with 5% interest rates result in monthly payments of $4,487.70, or $43,080 per year, which is more than the anticipated income per year from operating the solar farm.

There's one small problem here. The monthly loan to purchase the solar farming equipment greatly exceeds the total monthly income generated by the solar farm. This assumes ongoing equipment maintenance costs are essentially zero and none of the equipment fails or gets damaged by severe weather.

An acre of land in Texas is very cheap, so I've not included land purchase prices, which are negligible in this case. For all practical purposes, suitable land in Spain is not that much more expensive than it is in Texas, but it's still about 2X more expensive, on average.

An acre of land used to farm corn might produce similar results:

The net profit per acre for corn can vary significantly based on factors like yield, market price, and production costs. However, a 2023 study suggests a median net return of around $128 per acre for conventional corn, with a range from -$775 to $1,160 per acre between the bottom and top deciles. In Texas, average corn yields are around 105 bushels per acre, with a market price of $5.70 per bushel, according to the Texas Corn Producers.

Texas is pretty far from ideal for growing corn, but after 25 years of farming, growing an acre of corn will yield about $14,962.50 per acre.

The average cost to grow corn per acre is between $600 and $856, depending on factors like location, yield, and input costs. For example, in 2024, the USDA estimates the average cost to grow corn to be $856 per acre. farmdoc daily reported that total costs for corn production in central Illinois reached $579 per acre in 2023, with a projected decline to $527 in 2024. These costs include expenses like seed, fertilizer, herbicides, and fuel.

At $856/acre, growing that corn costs $21,400 over 25 years. That means the farmer is out $6,437.50 per acre after 25 years of farming.

At $41,832.48/acre, you get $1,045,812 in total income after 25 years. Total loan amount is $1,077,047.77, which means you're now $31,235.77 under water at the suggested wholesale electric power rates from the article, after 25 years, as opposed to only $6,437.50.

The rate figures that both food and solar farmers throw out there are clearly not representative of reality, or if they truly are representative, then almost nobody is making any money through these business models, except through rate / tax payer provided subsidies. The teacher at the FFA meeting for the class my daughter takes in high school told me that farmers either become masters of managing debt and making money off of side hustles, or they go bankrupt. I'm starting to think that photovoltaic farming is merely another part of the same gig, if the numbers they're throwing out are realistic, and I notice that farmers frequently have them on farmland here in the US.

All the talk about photovoltaic power only costing $0.02/kWh is either errant nonsense or a road to poverty. A company operating the panels cannot make enough money to pay off the equipment loan at that rate, unless they get a sweetheart deal on the loan rate. In reality, true cost to the consumer is about $0.30/kWh for wind turbines, $0.20/kWh for photovoltaics, $0.15/kWh for new nuclear, $0.10/kWh for natural gas, and $0.05/kWh for coal. You can get some variation within those pricing tiers dependent upon how ideal any given location is for the specific type of power plant you're building. Wind is cheaper in very windy areas, solar is cheaper in deserts, and natural gas can be very cheap here in America because we have a large surplus and highly optimized infrastructure to transport and use it for electric power generation.

What I see here is that the total taxable income, per acre, from operating utility scale photovoltaics is very small, relative to the loan cost, which does not include any of the necessary grid upgrades, which must be paid by the consumer. It takes more than half the rated service life of the photovoltaics to pay off the small business loan, assuming said small business sells power into a pool managed by a conglomerate or larger service provider responsible for managing the grid infrastructure. That's a typical operating model here in America, but I readily admit I understand little to nothing about grid operations in Europe because it's outside of my experience. This is a big bright flashing warning indicator that the power being generated per unit of land area is almost irrelevant to the national economy in terms of net economic value added merely from operating the power plant, apart from all the debt incurred by the solar farm operator to supply power to their consumers. The panels themselves probably represent 50% to 60% of the total cost, at $200 to $250 per panel, but the rest of the labor, equipment, and materials costs are significant.

kbd512 · Not So Free Chat

This is what output from Spain's near-100% renewable electric grid looked like on the day of their grid crash:

This same type of event has happened on green energy grids before, with less catastrophic consequences because the total percentage of "green energy" generating capacity was lower:

The vertical drop in the load seen in the first chart for the Spain / Portugal grid crash event wasn't because 12.5GW of generating capacity was suddenly "not required" mid-day. Spain was undoubtedly voraciously consuming electricity to power AC units, businesses, industry / manufacturing, home appliances, and computers. It was automatically removed by computerized control systems scrambling to avert widespread destruction of attached electrical and electronic equipment, because that might take months to recover from. I can promise you that the photovoltaics themselves didn't malfunction, nor did any weather-induced event cause them to quit producing power. There is zero evidence supporting either of those possible causes. Red Electrica cannot find any cyber intrusion or human error event preceding the grid crash, either. In point of fact, both the wind turbines and photovoltaics were humming along quite nicely. That wasn't the issue. The issue is that the generating machinery is only one part of a much larger electric grid machine. Electric energy grids are in fact the largest and most complex types of machines humanity currently produces.

The automatically commanded load shedding caused a frequency instability and subsequent cascading failure because Spain's grid has insufficient inertia to overcome perturbations from load-shedding of the magnitude possible as a result of the selected energy sources, namely wind turbines and photovoltaics. Using power inverters connected to the wind turbines or photovoltaics is like balancing a jello block on a wet noodle. The only way that works at all is if a computer is instantly deciding when and how to load and unload the grid to stave off a catastrophic failure. Good job to whomever implemented those control systems, because otherwise Spain still wouldn't have a functional electric grid, but whomever designed the portion of the machinery responsible for frequency control seriously underestimated the magnitude of power buffer required. Spain's green energy grid failure was complete inside of 5 seconds, after which the power was out "coast-to-coast", so-to-speak, while the interconnected portions of Europe's electric grid scrambled to prevent the failure in Spain from spreading to the rest of the grid.

At the time of the failure the weather over Spain was ideal for wind turbines and photovoltaics to generate electrical power, there was no wild fluctuation in supply or demand prior to the grid crash, and yet, Spain's "green energy" still failed miserably at delivering reliable and stable power output. If this same energy system was implemented on Mars without the reliable baseload nuclear power that was so clearly missing from Spain's energy grid, because the Spanish authorities deliberately forced the nuclear power operators to shut down their reactors, in a misguided attempt to prove that their "green energy" fantasy works, then everybody in the Mars colony would be DEAD!

Whenever objective physical reality disagrees with the ideology of the left, they fall back on their ideology, because they're a religious cult. The left has become the very thing they incessantly attack Christianity for being. The left is no different and no better. The left has become profoundly anti-scientific and anti-evidence-based thinking.

France's electric grid, which is primarily powered by nuclear reactors, experienced no similar power disruption over the same time period. The only part of France's electric grid which was disrupted, was the portion of their grid which receives electricity from Spain's electric grid. Whether Spain's electric grid was somehow affected by ideal weather for "green energy" or by some defect with the grid itself, somehow the people who predominantly rely upon nuclear power experienced no power disruption while the people who predominantly rely upon wind turbines and photovoltaics were plunged into darkness for an entire day. The estimated cost of the power disruption to Spain and Portugal would pay for a brand new nuclear reactor. Either way, the outcome points to incompetence on the part of our green energy advocates. They clearly don't know what's required to run a reliable green energy grid, or they refuse spend other peoples' money on the systems and services required to ensure its reliability. Actual experts have warned them about what would and did happen if they continued along their present course of action.

Closer to home, our own leftists are attempting the same insanity:
Spain’s Blackout Raises Massachusetts Energy Grid Fears

The definition of insanity is trying the same thing over and over again, while expecting different results.

This is precisely how and why communism fails. There's an obvious fundamental problem that the ideologically-captured are trying to ignore with all their might, the exact problem and prescribed solution has been outlined by real experts who are simply making evidence-based observations about objective reality, those making decisions about what to do or buy or execute on pretend that the problem and the evidence isn't real because it runs afoul of the ideology, and then disaster inevitably occurs when, not "if", ugly objective reality asserts itself with full force, just as it always has and always will. You do not have to be an "expert" to understand why an electric grid that cannot control voltage, amperage, or frequency is likely to fail. A child who has ever used a battery operated toy knows that if a toy has space in the battery compartment for 4 batteries, that 3 is too few and 5 is too many, because that's how the toy was designed to work. It's not an ideological judgement on the relative to merit of using one energy source over another, nor 3 vs 4 vs 5 batteries, it's acquiescence to the practical aspects of making sure that the electric grid machine remains functional.

The same kind of judgement could be rendered on the RBMK nuclear reactor designs that the Soviet Union used. They were repeatedly warned about potential catastrophic consequences from design flaws from both western and eastern nuclear physicists who understood reactor design principles. Those in charge ignored the serious technical defects because addressing them required spending a lot of money, so then it was only a matter of time before disaster struck. In retrospect, not putting Graphite tips on Boron control rods to "save a little money", was a comparatively incredibly cheap concession to objective technological reality. Nobody would've died, no nuclear power reactor would've exploded, a second RBMK reactor would not have been damaged, and according to Secretary General Gorbachev, the Soviet Union would not have been bankrupted. My gosh, but a little extra Boron seems like a very very small price to pay for a reactor that couldn't "run away". Even if they wanted to "go with the cheaper option", they ought to have told their reactor operators, "Hey, fellas, don't withdraw or insert all of the control rods at the same time, or your reactor is going to run away and explode." Even that solution, which required no money but involved not hiding the RBMK's serious potential intrinsic design defect, was "too much to ask", because the state had to pretend that their flawed reactor design was somehow "superior" to the PWRs used by the West.

Real "green energy" of the reliable and stable variety starts with a massive amount of inertia created by fundamental forces- flowing water, a large mass of very hot material, or spinning metal. That is how stable electric grids work. You cannot easily turn them on and off, because they have a massive amount of inertia preventing them from becoming unstable, and the underlying mechanism providing said stability tends to automatically push the system back into stability. All the people who built the electric grid before computers were invented were not simpletons who were "behind the times" when it came to their understanding of technological advancements. They learned the hard way, and then made appropriate changes to prevent future problems. Now we have this group of people in charge who are ignorant of history, who think a highly precise and fast-acting computer control system can be an acceptable substitute for the energy buffering that was deliberately built into traditional steam-turbine based energy generating systems. Unfortunately, that's not working out very well. Maybe it does work most of the time, but the standard is "working all of the time". If a national level electric grid is only functional for 364 days out of 365 days, that's unacceptable.

kbd512 · Not So Free Chat

What caused Spain and Portugal's power cut? | BBC News

Spanish power company Red Eléctrica has ruled out a cyber-attack as the cause of Monday's mass blackouts, that left millions across Spain and Portugal without power.
Portuguese Prime Minister Luis Montenegro also said there was no indication that a cyber-attack was behind the outages.
Electric grids suffered two "disconnection events" - systems recovered from the first, but the second triggered the power cuts in both Spain and Portugal, with no indication of human error.
Power has now been fully restored in Spain and Portugal but travel disruption continues.

The PM doesn't want to "jump to conclusions", but doesn't believe any kind of cyber attack or computer-related interference is involved, and it does not appear that "human error" was involved, either.

Two "disconnect events" took place mere seconds before the blackout, wherein the country's solar power fields either quit delivering power to the grid or producing power. Either way, there were widespread blackouts in the most populous cities of Spain and Portugal.

My favorite comment from the comments section:

"we rushed to install renewable generation but didn't beef up the grid to handle a more volatile power input....but we don't want to admit that"

Fact check: Did solar power cause the Iberian blackout? - Jan D. Walter

The grid operators needed more than a day to fully restore the power supply in Spain and Portugal. One of the circulating theories is that excessive solar power caused the blackout. Is that true?
As soon as the lights went out in Spain and Portugal, the speculating about the cause of the blackout began. Was it a cyberattack? Atmospheric interference? Aliens?Though the Spanish government is looking into the possibility of a cyberattack on the Spanish electricity grid, the head of the Spanish electricity transmission system operator Red Electrica (REE), Eduardo Prieto, has ruled this out already.
Extreme frequency fluctuation
According to Prieto, two apparently separate incidents that happened within 1.5 seconds of each other in southwestern Spain threw the grid frequency off balance. He said that this caused the outage of power plants with a capacity of 15 gigawatts (GW) — almost half of the active power plant capacity at the time.
Very large and sudden deviations can cause a cascading failure, whereby extreme frequency fluctuations trigger elements and mechanisms in other power plants (and large consumers), which then automatically take these plants off the grid.
Prieto described it as quite possible that this domino effect may have been triggered by solar power plants.
Does that mean critics of renewable energies are right when they say that an oversupply of solar power triggered the blackout?
Claim: "Renewables, in this case solar, have just caused the first major #power outage in Spain, specifically due to an oversupply of solar," an alleged physicist with a German account, posted on X, formerly Twitter, garnering almost 100,000 views (as of 30.04.2025, 16:40).
The user refered to Fritz Vahrenholt, a German chemistry professor and manager, who is critical of energy transition efforts and had explained in another post on X, which attracted more than 400,000 views, that before the grid failure in Spain, the production of renewable energies, especially solar, had increased more than demand.
DW fact check: Unproven
The cause of the power outage has not been conclusively clarified. It is correct that at the time of the blackout, solar energy provided around 60% (19.3 GW) of the power available in the Spanish grid. Moreover, it appears that solar power plants dominated electricity production in the southwest of Spain.
Did all PV systems suddenly switch off?
For energy transition critic Fritz Vahrenholt, there is no doubt that the surplus of photovoltaic (PV) power in the Spanish grid was the "primary cause," as he told DW by email. He said that Spain had been forced to export electricity to France as a result.
The "secondary cause" was the loss of this transmission line and as a result "all" the PV systems had then "abruptly" disconnected from the grid, he said.
However, PV systems are not supposed to shut down abruptly. because standardized regulations for electricity producers have been in force in the EU since 2016.
These regulations stipulate that PV systems have to gradually reduce their feed-in if the grid frequency exceeds the limit value of 50.2 hertz (Hz) due to a power surplus.
"In Spain, corresponding grid connection guidelines were introduced at the end of the 2000s to ensure that PV systems do not simply disconnect from the grid in the event of a sudden grid fault," said Sönke Rogalla, a researcher at the German Fraunhofer Institute ISE, Europe's largest solar research institute. He explained that these properties were verified prior to operation as part of certification procedures.
Furthermore, data avaiable so far also contradict Vahrenholt's thesis. Even if all solar plants had been taken off the grid at the same time, there would not have been a shortfall of 15 GW, but at least of 20.4 GW as the PV output at the time of the blackout was at least 17 GW.
However, also nuclear power plants, which supplied 3.4 GW, were taken off the grid as a precautionary measure.
Is high PV power a problem for electricity grids?
It is documented that Spain's power grid connections to France and Portugal were capped during the blackout. However, it is still unclear whether this was the cause of the blackout in Spain or one of the domino effects.
What is certain is that Spain exported a net total of 3 GW shortly before the grid disconnection. As a result of the interruption to the power lines, this surplus was suddenly available in Spain. Such an incident would undoubtedly be a major burden for any electricity grid.
Vahrenholt believes that the low number of coal and nuclear power plants in Spain was an additional problem, as the turbines of such power plants can serve to smooth frequencies.
This stabilizing effect, known as instantaneous reserve, was probably lacking in Spain, wrote Enrique Garralaga, a managing director at a subsidiary of the German PV component manufacturer SMA, in a LinkedIn post.
"Technical solutions are available"
Fraunhofer researcher Rogalla confirmed that this could have contributed to the blackout but he had a different perspective: "The blackout in Spain was not a PV failure, but probably a system failure," he said, adding that "in this respect, I see it as an urgent reminder that the restructuring of the energy system poses major challenges."
With the systems installed today, it is not possible to operate an electricity grid with solar and wind power alone, he said. He also rejected the claim that a high proportion of renewable energies was an unsolvable problem. "We are constantly learning. The technical solutions are now available, now we have to set about implementing them."
The outgoing German government outlined a possible way forward in a roadmap. The regulatory authority, the European Union Agency for the Cooperation of Energy Regulators, or ACER, has already submitted
a proposal for the implementation of new solutions at EU level.
Conclusion: The theory that 'an oversupply of solar (power)' was the reason for the blackout cannot be substantiated. Although a high proportion of renewable electricity in the grid is one of the major challenges of the energy transition, it is not an unsolvable problem.
This article was originally published in German.

After claiming that Vahrenholt's claim was "unproven", the article then goes on to explicitly state that the grid instability was directly caused by the photovoltaics.

Let's perform a "real fact check" on Jan D. Walter's "net zero ideology check":

The person writing the article attempting to "fact-check" Vahrenholt's central claim explicitly stated that the photovoltaics were factually at-fault for the power trip that took down most of the nation's grid, and that 3GW of power from photovoltaics was suddenly "dumped" onto Spain's over-capacity electric grid at a time when it could not be locally consumed.

Walter admitted this right here:

What is certain is that Spain exported a net total of 3 GW shortly before the grid disconnection. As a result of the interruption to the power lines, this surplus was suddenly available in Spain. Such an incident would undoubtedly be a major burden for any electricity grid.

To protect itself from a near-instant "grid overload" directly caused by Spain's photovoltaic power source, the automated computerized systems controlling Spain's electrical grid disconnected from their photovoltaic power source to prevent widespread grid infrastructure damage or destruction, as well as potential damage or destruction of all connected electrical and electronic devices, because Spain's grid was designed in such a way that it had no ability to "dump" that much excess power into the ground.

17GW of power was being consumed in Spain at the time of the disconnect. Suddenly, another 3GW of power "showed up" on Spain's electric grid without a load to consume it.

Q: Can you deliver 15% more total power than all grid-attached electrical / electronic infrastructure is presently consuming without "blowing stuff up"?
A: Hell, no!

If you supply 15% more voltage and/or amperage to a computer than whatever it's rated to accept as input, then you will cease to have a functional computer within one second. This is what Spain's photovoltaic power source directly caused when (quite obviously) there was no ability to consume the generated power in France through their grid-interconnect, nor Spain and Portugal.

When Professor Simon Michaux says grid supply and demand have to be almost perfectly balanced to within a millionth of a second, he's not over-hyping objective physical reality. It's a simple "state of truth" about what awaits if ever electrical power supply and demand fail to match. Spain and Portugal only got a little taste of this part of objective physical reality, as it relates to widespread deployment of photovoltaic and wind turbine power, without an electrical grid capable of handling the wild power fluctuations that are "baked-in" to any grid primarily relying upon highly variable and intermittent photovoltaic and wind turbine power output.

kbd512 · Not So Free Chat

Yuri,

There is only one correct approach to US involvement in the war in Ukraine. If our Congress thinks defending Ukraine from Russia's military assault is in our national interest, then they should declare war on Russia. Congress and the President should articulate to the American people why declaring war against Russia is the only viable option. After the explanation has been given, American troops should be sent to Ukraine to fight should-to-shoulder with the Ukrainian troops.

I'm no longer the young man that I once was during the six years I spent in the US Navy, but if I was drafted following an actual declaration of war, I would go and fight for what my nation's leadership has determined is the correct course of action. I will do that because I believe freedom from tyrants is worth fighting for. I think that way because I have morals. Basic morality says you cannot stand there while your friend is being attacked, merely because you were not also attacked. That's like pretending your friend is not actually your friend. No true friend who has basic morality can act that way. We've supplied billions of dollars of weapons to Ukraine, and have sent our special forces into Ukraine, but have no formal declaration of war. We need to be clear and truthful about what we're doing.

The United States of America has two reasons to continue to exist:
1. America is a beacon of freedom and prosperity for people who wish to create a better life. Only the possibility of a better life is offered. It's not a promise. Whether or not freedom and prosperity is achieved is purely a function of our willingness, as Americans, to work towards that goal.
2. America is a bulwark against the worst humanity has to offer. We're willing to make difficult decisions when others will not.

If America doesn't stand up for those principles, then nobody else will. Worse than that, America has no reason to exist. The title "Leader of the Free World" is not a pleasantry. It comes with certain duties and responsibilities that cannot be ignored for sake of convenience.

Whether or not the Russians decide to use nuclear weapons is up to Russia's leadership. In practical terms, there's nothing anyone else can do about that. I don't fear Russia or their nuclear weapons, in much the same way that I don't fear hostile space aliens or a giant asteroid headed towards Earth. I know that the threat is real, but there's little anyone can do about it. If any of those scenarios occur, there's no practical response using our existing technology. We can only grit our teeth and take the hit, as painful as that may be. The survivors pick up the pieces and try to soldier on, because that's all they can do.

New Mars Forums

Announcement

#151 Re: Not So Free Chat » Peter Zeihan again: and also other thinkers: » 2025-05-15 17:27:24

#152 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-15 13:35:04

#153 Re: Not So Free Chat » Peter Zeihan again: and also other thinkers: » 2025-05-15 12:23:33

#154 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-15 11:54:50

#155 Re: Meta New Mars » kbd512 Postings » 2025-05-15 09:35:02

#156 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-15 03:19:49

#157 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-14 19:19:29

#158 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-14 17:23:23

#159 Re: Interplanetary transportation » Universal Ion Propulsion » 2025-05-14 16:24:23

#160 Interplanetary transportation » SpaceX's Effect on Launch Services Cost / Availability » 2025-05-14 16:18:51

#161 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-14 12:25:30

#162 Re: Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-14 10:05:52

#163 Human missions » Mars Ascent Vehicle - LOX/LCO vs LOX/LCH4 » 2025-05-14 02:35:42

#164 Re: Not So Free Chat » Oil, Peak Oil, etc. » 2025-05-12 09:06:20

#165 Re: Science, Technology, and Astronomy » Google Meet Collaboration - Meetings Plus Followup Discussion » 2025-05-11 19:20:49

#166 Re: Not So Free Chat » Oil, Peak Oil, etc. » 2025-05-11 16:19:22

#167 Re: Not So Free Chat » Oil, Peak Oil, etc. » 2025-05-11 12:30:53

#168 Re: Single Stage To Orbit » SSTO Engine Technology » 2025-05-10 15:46:08

#169 Re: Not So Free Chat » Politics » 2025-05-10 11:11:54

#170 Re: Not So Free Chat » Oil, Peak Oil, etc. » 2025-05-10 08:49:30

#171 Re: Science, Technology, and Astronomy » Plastic Car Automobile Truck Diamond Carbon No Metals » 2025-05-07 11:05:34

#172 Re: Not So Free Chat » When Science climate change becomes perverted by Politics. » 2025-05-05 17:01:19

#173 Re: Not So Free Chat » When Science climate change becomes perverted by Politics. » 2025-05-05 12:11:00

#174 Re: Not So Free Chat » When Science climate change becomes perverted by Politics. » 2025-05-03 14:55:01

#175 Re: Not So Free Chat » Politics » 2025-05-01 08:34:57

Board footer