Constructing a human mission, a tonne at a time

SpaceNut · 2020-01-05 20:14:19

If all starships are returning that means each has there own respective ispp facility built into it cutting it the support of each payload for construction on mars.

noosfractal list of things we need

kbd512 · 2020-01-05 22:50:53

Louis,

The first jet engines wouldn't run for more than 25 hours before they were completely destroyed from the heat generated. There is no war on and getting to Mars before "the other guy" doesn't mean anything if you end up dying there or along the way from insufficient testing. Oddly enough, militaries that wage successful wars seem to be of the same opinion when it comes to using a battlefield as a test facility. In other words, you can think about, but don't do it. There's always some level of experimentation in war time, but betting your life on something working that's never been properly tested is just a really bad idea and an act of desperation, no matter when or where you do it. Furthermore, despite what you claim, cost is entirely relevant to this mission. That's another idea you've constructed in your head that doesn't even seem to agree with what Elon Musk has stated as it pertains to spending a reasonable amount of money to go to Mars.

Regarding timelines, who's timeline are we operating on, yours or the people doing all the development work?

It was about 30 years from the time the first jet engine was used in an aircraft until jet engines had TBO's comparable with the piston engines of the day. Gas turbines are significantly more powerful than piston engines for a given weight, but only at extreme operational cost. The TBO's for first generation jet engines, no matter who made them, were typically 50 hours or less, which meant you spent far more time tinkering with the engine than actually flying the aircraft. While those engines technically "worked", only militaries and major airliners could afford to operate them and catastrophic failures weren't unusual. Modern jet engines are amongst the most reliable power plants in existence, but that level of reliability required approximately a human lifetime to achieve- 70+ years from the first run until multiple technological generations later we had jet engines that would run for years with minimal maintenance (actually spends more time flying than being torn apart).

The V2, whilst being a notable technical achievement, was nowhere near as effective as bombing targets using the technology of the time, if casualties and destruction were any indication- and they were. I'm sure the V2 scared people, or maybe not since you'd never hear it or see it coming, and it even killed people and destroyed some buildings in London, yet had precisely zero practical effect on the outcome of the war. I don't think Hitler or his scientists had any idea about how to actually win against numerically superior forces. It seems more like they were just throwing ideas against the wall, hoping something would stick. That's a recurring theme with creative but disorganized people. If they had any clue about what worked well, they'd not waste a minute of their time on "vengeance weapons". Germany desperately needed effective surface to air missiles to shoot down incoming enemy bombers, which they didn't have because they squandered their limited braintrust / money / resources on ineffectual "wonder weapons", much to our good fortune. Even with as many bombers as we made during the war, there was no way we could match the economy of singular SAM's that could obliterate them. Our bombers were more than 10 times the cost of the few limited production SAM's that Germany did develop. If the enormous resource expenditures associated with the V1 and V2 programs were directed towards SAM's, it's highly probable that both the RAF and the 8th USAAF would've been forced to suspend the bombing campaign against Germany. That would've had a profound effect on the war.

I don't even want to think about what kind of living hell we would've faced if the Germans made half-way intelligent military technology development decisions regarding what tools, tactics, and strategies to spend the most time and effort on. WWII could easily have gone on for 10 years or more. Even nuclear weapons only work when you can deliver them to their targets. Between SAM's, only building survivable twin-engined aircraft, using cheap but very effective assault guns like the "Sturmgeschütz" vehicles, and assault rifles, I don't even think the Russians would've been able to stop them.

The point behind that shallow dive through part of the history of a period of rapid technological advancement is pointing out the logical fallacies that so many people hold towards newer technology, what actually matters, and what doesn't. Reliable transportation matters. Reliable energy sources matter. The advantage conferred by "better" technology is typically limited to how fast or easily something can be accomplished. No revolutionary new technology will be forthcoming in the fanciful world of "tomorrow", especially if defined as the next 5 years, even though future technology improvements could make existing problems easier to solve.

Even though we've known about the Sabatier reaction for more than a century now, we're just now developing the technology at sufficient scale to use it for this particular use case. That normally means there's not much of a practical application for the technology. I certainly hope you're right about normal commercial considerations not governing the technology developed for Mars missions, but thus far I only see governments and civilian corporations to achieve this goal and funding still appears to be as much of an issue as it ever was.

I spent so much time on Lemvig because you keep throwing out "what-if" ideas as though there aren't any practical impediments between the ideas in your head and actualization of those ideas through real engineering. You're the one who brought up Lemvig as if something they're doing is relevant to a Mars ISPP plant. I keep going wherever you want to go, but I also point out all the problems and you keep ignoring them. The V2 is toy compared to what SpaceX is trying to build, so what relevance does a war time program implemented by a country that lost the war have to do with development of the technology required for Starship to work as envisioned? They went to the moon in 10 years, so they should be able to go to Mars in 10 years. That seems to be the "visionary" logic. Then current technological reality rears its ugly head.

It took a decade of development to get Falcon 9 to where it is now and far longer to get Falcon Heavy operational than even Elon Musk thought it would take. Why? In the world of real engineering, it wasn't as simple as putting a banding strap on 3 Falcon 9 boosters and calling it a day. They ended up completely redesigning the rocket's core booster stage. They never thought about strapping 3 booster cores together when they designed it. Oops.

They played with CFRP until they figured out that there was no way for them to meet the cost and timeline targets using a technology that none of them were familiar with- precisely why they hired an independent firm to fabricate and test the giant propellant tank test article. Now they're playing with stainless steel, which once again, they clearly have little idea about how to use. Why? It's certainly not because they're not smart or capable. It's that "operational art" that GW always talks about that you studiously ignore because it's not telling you what you want to hear. Aerospace welding is almost an art form and what you'd do is very nearly as situationally-dependent as it is procedural. There's more than one "right way" to do it, but at least as many "wrong ways" as well. Unfortunately, the only way you begin to understand stuff like that is through experience that you only get after you need it.

In closing, I'm not trying to "divert" to anywhere. I simply stated what would actually be required if we actually wanted to get the ships back because, as Elon Musk has repeatedly pointed out, these things aren't exactly cheap and it's a shame to throw away perfectly good rockets after a few minutes of use.

Could we ever discuss any of these plans in a way that at least acknowledges that current technological reality matters in some small way?

kbd512 · 2020-01-05 23:36:05

Louis,

Tell you what. If we can get a single successful LOX/LCH4 ISPP demonstrator mission under our belt, no matter how much we have to scale up the technology and power to do what SpaceX wants to do, then I'll call it good to go. As of right now, I don't see any mission that doesn't bring the propellant to get home as being a viable plan. At best, it's a crap shoot. SpaceX already has the rocket technology to test this on Mars. If they have the MOXIE, then just do it. Someone needs to stop talking a good game about ISPP and start demonstrating it on Mars. A lab demonstration won't do. We're not sending people to a lab somewhere on Earth. The first crew will be farther from home than anyone has ever been. Their lives are worth the due diligence through realistic testing. I can't think of a more realistic test environment than Mars. If there's not enough money in the R&D budget to do that, then there's nowhere near enough to actually send humans there.

louis · 2020-01-06 03:53:02

Just came across this:

Musk has previously confirmed that in-house design work on a Sabatier reactor was "pretty far along" back in 2017.

https://www.teslarati.com/spacex-resear … g-on-mars/

Only words I know, but I think it's probably comments such as that which have led me to conclude Space X are probably making more progress on this than we we are necessarily aware of.

kbd512 wrote:

Louis,
Tell you what. If we can get a single successful LOX/LCH4 ISPP demonstrator mission under our belt, no matter how much we have to scale up the technology and power to do what SpaceX wants to do, then I'll call it good to go. As of right now, I don't see any mission that doesn't bring the propellant to get home as being a viable plan. At best, it's a crap shoot. SpaceX already has the rocket technology to test this on Mars. If they have the MOXIE, then just do it. Someone needs to stop talking a good game about ISPP and start demonstrating it on Mars. A lab demonstration won't do. We're not sending people to a lab somewhere on Earth. The first crew will be farther from home than anyone has ever been. Their lives are worth the due diligence through realistic testing. I can't think of a more realistic test environment than Mars. If there's not enough money in the R&D budget to do that, then there's nowhere near enough to actually send humans there.

SpaceNut · 2020-01-06 18:29:31

Not much in the article so went for a google...
we had hoped for a test upper stage but here is that status
https://www.teslarati.com/spacex-ceo-el … ouncement/

The goal is to use in-situ resource utilization to create more fuel. The teams would take water and carbon dioxide to make liquid oxygen and methane. The carbon dioxide would come from the atmosphere, and the water would come from ice reserves. The team uses electrolysis to split water into oxygen and hydrogen, and uses the Sabatier process to take carbon dioxide and hydrogen and create water and methane.

Yes that will save mass of launch for the outward journey bit also for what we can land that changes the ability to land on mars for a bfr starship.

https://www.inverse.com/article/60133-s … uel-depots

“Depends on total system efficiency & how long the propellant plant can run to refill Starship, so 1 to 10MW as a rough guess,”
Assuming an average of one megawatt over a day and night cycle, this would require a solar array measuring 40,000 square meters.

Error in wattage is what is not a day cycle...as that is the whr and that is not true for solar either as ther is the slow rise to high noon and then the slow fall until night. So no that does not calculate...

Depending on the solar panels in use, Zubrin estimates that an array may weigh around 4 kg per square meter. That would result in a mass of around 160 tons. Each Starship is estimated to carry around 150 tons of cargo, hence the need for multiple Starships.

Ya that is going to be the issue for packaging them into the cargo area as well as for selecting the efficiency of the panels as the mass does not go hand in hand with either material or efficiency as some require mass in framing to make them work as well as to align them.
I have given estimates for volume of just the panels less packaging to protect them.

Zubrin estimates that producing two tons of liquid oxygen and methane every day would need around one megawatt of power. The power figures cover carbon dioxide acquisition, electrolysis, and cryogenic liquefaction.
If the team requires 780 tons of fuel to return home, that means that it would take around 390 days to produce enough fuel to come home, or a year and a month.

Yup energy will go up for the shorter duration being used to manufacture the propellant but what he does not go into is the energys to gain co2, to harvest the ice or the heat required to make the water let alone the filtering of dust and minerals from the water.

musks-explanation-of-using-carbon-capture-to-make-rocket-fuel.png?auto=format%2Ccompress&dpr=2&w=650

Image details are:
5 million cubic km ice
https://www.aqua-calc.com/calculate/vol … lank-solid

1 cubic foot of Ice, solid weighs 57.3713 pounds [lbs] Ice, solid weighs 0.919 gram per cubic centimeter or 919 kilogram per cubic meter , i.e. density of ice, solid is equal to 919 kg/m³. In Imperial or US customary measurement system, the density is equal to 57.4 pound per cubic foot [lb/ft³], or 0.531 ounce per cubic inch [oz/inch³] .

https://www.convert-me.com/en/convert/v … ?u=km3&v=1

25 trillion metric tons co2
http://www.uigi.com/co2_conv.html

Of course none of this is a 1 mT or 2 mT for delivery and that is the issue for building up to a large vehicle.

SpaceNut · 2020-01-07 18:32:15

Conducting mission for mars with what we have will sort of be like this

Granted I think we can do better than a ton or two but the landings will be no dragon or skycrane as they are.
The skycrane is a set of canted engines like as the red dragon or crewed version. As I indicated cargo will not need the heavy pressure vessel.

SpaceNut · 2020-01-08 21:44:30

Things that we will need to do with that cooking thing...
For the processing and preparation of the plant material into acceptable
food, certain equipment is analyzed, including the following: [Parks et al., 1994]
• Extruder
• Grain/flour mill
• Soy milk machine
• Food processor
• Bread machine
• Dishwasher
• Refrigerator
• Freezer
• Dehydrator
• Press (oil extraction hydraulic)
• Pasta press
• Automatic tofu/milk machine
• Galley
• Stovetop
• Toaster oven
• Mixer
• Convection oven
• Bagel maker
• Blender

SpaceNut · 2020-01-09 20:13:13

Mars One was an attempt to build on a sort of exisitng capsule capability that when grouped would comprise a one way mission of hearty souls.

sending 6 units

with finally human crew of four in 2024

louis · 2020-01-10 20:01:22

With a Space X Mission One, you have 500 tons to play with. You might be looking at 150 tons for your energy system, maybe 50 tons for your methane manufacturing unit. Rovers, mining equipment, 3D printers and other "industrial" equipment might take another 50 tons.

You still have 250 tons left. For Mission One habs, we might be talking about two or three habs. I doubt they'd weigh in more than 5 tons a piece as units themselves. The double air locks might add a couple of tons (they don't need to be so robust as the rest of the structure, as they don't have to support permanent radiation protection). So if we had three hab spaces, maybe it would be 5 x 3 plus 2 x 3 = 21 tons.

So, even on that basis you'd have at least 225 tons remaining. Of course I think for Mission One a lot of that will be emergency food supplies, water, medicines and medical equipment.

Regarding hab mass, the only thing I can find to go on are the Bigelow units.

https://en.wikipedia.org/wiki/Bigelow_E … ity_Module

1.4 tons for 16 cubic metres of space.

I think a hab unit for 6 people might occupy 7 x 7 x 3 metres = 147 cubic metres.

Scaling up that gives you 12.9 tons but -

1. I think as you scale up the ratio of tonnage to cubic interior reduces...maybe someone who knows about these things can confirm (it's the elephant principle, they are big which means they can contain more than a smaller animal, proportionally per skin area unit). So if I am right then the 12.9 tons figure would go lower.

2. Bigelow are building for space, not planetary surfaces. On Mars we can reduce the hab mass and load on regolith to give the radiation protection.

My mass figure for a hab - 5 tons might be too low but I doubt it will be above 10 tons. Even if it was 50% more, that's still only 28.5 tons in total, I don't think the double air locks would mass any more.

Happy to have my guesstimates critiqued!

SpaceNut wrote:

Every watt for a power source or sources, mass gram to metric ton of deliverables to mars matters for survival.
So whats the mass of the safe entrance garage?
Whats the mass and energy needs to make the garage port?
What is the total add ons for a safe habitat to rover connection egress unit?
What is the EVA mass and portable energy needs for operation for the rover for clean entrance system?
For a construction or foundary module its only going to a contaminant while in operation, so we close the connecting hatch and give safe haven with in the module for if a mishap occurs. So when the shift is done the equipment is turned of and the atmosphere is check to validate it before opening the connecting hatch.

Last edited by louis (2020-01-10 20:03:26)

SpaceNut · 2020-01-10 21:50:59

The brute force solution of multiple landings of starship to do what can not be done in the first 100 mT is not a solution its what nasa had trouble with in Battlestar galatica mission designs. Each needing multiple lanchers to refill the ship is also an issue for going to mars. It just does not work for one let alone the sheer number of them to make the 5 go to mars. Then you have the power to refueling needs to be able to come home, the quantity of fuel to even get 1 ship home. Its not simple.
The 5 ship mission also has never had a starship ever land on mars and sending them all at once is not something that any mission will be designed around. As you could not risk losing even one for any reason planning it that way.

SpaceNut · 2020-01-11 13:02:31

This is how you design with a ton at a time mind set.

We need to excavate regolith soil to process for water and its got to fit into current technology landings and power requirements of that down mass payload limitations.

Pioneering Space Requires Living Off the Land in the Solar System

RASSOR 2.0, the Regolith Advanced Surface Systems Operations Robot. RASSOR excavated regolith and delivered sand and gravel to a hopper and mock oven. Making about two pounds of fuel on Mars saves about 500 pounds launching it from Earth to get it to the Red Planet.

So a reduction of launch mass of 250 lb per that we can do insitu on mars by delivering a smart sized payload of a 1 mT package.

This is something that a Falcon heavy launch cost can do now...
So for the remaining of the marco polo lander is the processing to methane all within that landers capability.

SpaceNut · 2020-01-11 23:13:15

https://www.nasa.gov/sites/default/file … 6-ADD2.pdf

of the table pg30, which has the lander mass its for 6 crewmen for a 40mT lander, 4 crewmen are in a 20mT with of course anything small thought of as being to small...

pg33 shows the payload down mass and fuel requirements for the lander sizes

The use of beam and cygnus can make for a smaller mass without sacrificing

a 2 person crew needs
Crew Consumables 2610 kg
Science 480 kg
Robotic Rovers 200 kg
Drill 250 kg
Unpressurized Rover 200 kg

wish list
Pressurized Rover 7500 kg

mass may be zero or small depending on options taken
LOX Transfer Cart 400 kg
Habitat 19870 kg
Stationary Power System 7800 kg
ISRU Plant 1230 kg

SpaceNut · 2022-04-09 16:05:48

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#76 2020-01-05 20:14:19

Re: Constructing a human mission, a tonne at a time

#77 2020-01-05 22:50:53

Re: Constructing a human mission, a tonne at a time

#78 2020-01-05 23:36:05

Re: Constructing a human mission, a tonne at a time

#79 2020-01-06 03:53:02

Re: Constructing a human mission, a tonne at a time

#80 2020-01-06 18:29:31

Re: Constructing a human mission, a tonne at a time

#81 2020-01-07 18:32:15

Re: Constructing a human mission, a tonne at a time

#82 2020-01-08 21:44:30

Re: Constructing a human mission, a tonne at a time

#83 2020-01-09 20:13:13

Re: Constructing a human mission, a tonne at a time

#84 2020-01-10 20:01:22

Re: Constructing a human mission, a tonne at a time

#85 2020-01-10 21:50:59

Re: Constructing a human mission, a tonne at a time

#86 2020-01-11 13:02:31

Re: Constructing a human mission, a tonne at a time

#87 2020-01-11 23:13:15

Re: Constructing a human mission, a tonne at a time

#88 2022-04-09 16:05:48

Re: Constructing a human mission, a tonne at a time

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