Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

SpaceNut · 2018-08-12 16:03:51

Dr. Robert Zubrin on March 30, 2018
http://newmars.com/2018/03/moon-direct- … our-years/

Reposted from Space News

The recent amazing success of the Falcon Heavy launch offers America an unprecedented opportunity to break the stagnation that has afflicted its human spaceflight program for decades. In short, the moon is now within reach.

Here’s how the mission plan could work. The Falcon Heavy can lift 60 tons to low Earth orbit (LEO). Starting from that point, a hydrogen/oxygen rocket-propelled cargo lander could deliver 12 tons of payload to the lunar surface.

We therefore proceed by sending two such landers to our planned base location. The best place for it would be at one of the poles, because there are spots at both lunar poles where sunlight is accessible all the time, as well as permanently shadowed craters nearby where water ice has accumulated. Such ice could be electrolyzed to make hydrogen-oxygen rocket propellant, to fuel both Earth-return vehicles as well as flying rocket vehicles that would provide the lunar base’s crew with exploratory access to most of the rest of the moon.

The first cargo lander carries a load of equipment, including a solar panel array, high-data-rate communications gear, a microwave power-beaming set up with a range of 100 kilometers, an electrolysis/refrigeration unit, two crew vehicles, a trailer, and a group of tele-operated robotic rovers. After landing, some of the rovers are used to set up the solar array and communications system, while others are used to scout out the landing area in detail, putting down radio beacons on the precise target locations for the landings to follow.

The second cargo lander brings out a 12-ton habitation module, loaded with food, spare spacesuits, scientific equipment, tools, and other supplies. This will serve as the astronauts’ house, laboratory, and workshop of the moon. Once it has landed, the rovers hook it up to the power supply and all systems are checked out. This done, the rovers are redeployed to do detailed photography of the base area and its surroundings. All this data is sent back to Earth, to aid mission planners and the science and engineering support teams, and ultimately forming the basis of a virtual reality program that will allow millions of members of the public to participate in the missions as well.

The base now being operational, it is time to send the first crew. A Falcon Heavy is used to deliver another cargo lander to orbit, whose payload consists of a fully fueled Lunar Excursion Vehicle (LEV). This craft consists of a two-ton cabin like that used by the Apollo-era Lunar Excursion Module mounted on a one-ton hydrogen/oxygen propulsion system filled with nine tons of propellant, capable of delivering it from the lunar surface to Earth orbit. A human-rated Falcon 9 rocket then lifts the crew in a Dragon capsule to LEO where they transfer to the LEV. Then the cargo lander takes the LEV, with the crew aboard, to the moon, while the Dragon remains behind in LEO.

After landing at the moon base, the crew completes any necessary set up operations and begins exploration. A key goal will be to travel to a permanently shadowed crater and, making use of power beamed to them from the base, use telerobots to mine water ice. Hauling this treasure back to the base in their trailer, the astronauts will feed the water into the electrolysis/refrigeration unit, which will transform it into liquid hydrogen and oxygen. These products will then be stored in the empty tanks of the cargo landers for future use — primarily as rocket propellant but also as a power supply for fuel cells and a copious source of life-support consumables.

Having spent a couple of months initiating such operations and engaging in additional forms of resource prospecting and scientific exploration, the astronauts will enter the LEV, take off and return to Earth orbit. There they will be met by a Dragon — either the one that took them to orbit in the first place or another that has just been launched to lift the crew following them — which will serve as their reentry capsule for the final leg of the journey back home.

Thus, each mission that follows will require just one $100 million Falcon Heavy launch and one $60 million Falcon 9 launch to accomplish. Once the base is well-established, there will be little reason not to extend surface stays to six months.

Assuming that cost of the mission hardware will roughly equal the cost to launch it, we should be able to create and sustain a permanently occupied lunar base at an ongoing yearly cost of less than $700 million. This is less than four percent of NASA’s current budget — or about a quarter of what is being spent yearly on the agency’s now obsolete Space Launch System program which has been going on for over a decade without producing a rocket.

The astronauts will not be limited to exploring the local region around the base. Refueled with hydrogen and oxygen, the same LEV spacecraft used to travel to the moon and back can be used to fly from the base to anywhere else on the moon, land, provide on-site housing for an exploration sortie crew, and then return them to the base. We won’t just be getting a local outpost: we’ll be getting complete global access to an entire world.

Currently, NASA has no such plan. Instead it is proposing the build a lunar orbiting space station dubbed the Deep Space Gateway. This boondoggle will cost several tens of billions of dollars, at least, and serve no useful purpose whatsoever – except perhaps to provide a launch manifest for the Space Launch System. We do not need a lunar-orbiting station to go to the moon. We do not need such a station to go to Mars. We do not need it to go to near-Earth asteroids. We do not need it to go anywhere. If we do waste our time and money building it, we won’t go anywhere.

If you want to get to the moon, you need to go to the moon. We now have it in our power to do so. Let’s seize the time.

Robert Zubrin is president of Pioneer Astronautics and the Mars Society. An updated edition of his book, “The Case for Mars: The Plan to Settle the Red Planet and Why We Must,” was recently published by the Free Press

louis · 2018-08-12 16:18:46

A microwave power-beaming set up with a range of 100 kilometers??? We're nowhere near that are we?

SpaceNut · 2018-08-12 16:46:14

https://spacenews.com/op-ed-moon-direct … our-years/

I believe the staging to LEO is 63 mT for the falcon heavy but what is the direct to the moon throw?

https://www.reddit.com/r/spacex/comment … con_heavy/

As brought up in that topic the throw to orbit if not reusueable is quite a bit more as we saw with the falcon 9.

So guesstimates (using 65% of GTO throw mass) are:
Falcon 9 - 3,152.5 kg to TLI
Falcon 9 Heavy - 13,780 kg to TLI

Of course the question is Could SpaceX Get People to the Moon in 2018?

The private launch company must overcome several hurdles to meet its aggressive schedule for an ambitious lunar mission and we would all be quite happy to say yes they can..

Space x did sell tickets for a lunar mission sells first tickets for moon launch

There's room aboard the Falcon 9 for another 240 pounds of additional cargo. Astrobotic Technology is selling the space for $700,000 per pound, plus a $250,000-per-payload fee for integration, communications and other support services.
But a Falcon 9 heavy would do a lot better....

But it will not happen Space X delays tourist trip around the moon

RobertDyck · 2018-08-12 18:34:50

According to SpaceX website as of today. Falcon Heavy to LEO 63,800kg, to GTO 26,700kg, to Mars 16,800kg.

SpaceNut · 2018-08-12 19:00:04

https://www.thenewatlantis.com/publications/moon-direct

Phase 1
For delivering the base modules to the Moon — both for habitation and for propellant production — we need a separate cargo lander system. In Table 1 (see appendix), we can see how much cargo could be delivered to the Moon with a single launch of a variety of launch vehicles, plus a cargo lander system. This lander takes the cargo from a staging orbit — where the lander separates from the launcher — to the lunar surface.
The Falcon Heavy rocket can deliver over 8 tons of cargo to the lunar surface with any of the four options considered. We know that we will eventually need a launcher that can deliver at least 8 tons so that we can deliver the fueled LEV. The New Glenn and the Vulcan cannot deliver 8 tons. New Glenn can come close, however, and its large fairing — the cargo compartment at the top of the rocket — could make it attractive for delivering high-volume, low-mass payloads. The SLS can deliver more than what is required, and the BFR much more. But SLS, BFR, New Glenn, and Vulcan are not yet available. We will therefore plan to use the Falcon Heavy, which has a launch cost of $150 million.
To establish our base near the Moon’s south pole, we will deliver our initial cargo using two Falcon Heavy launches, which gives us a mass budget of 16 tons. The first cargo lander will deliver the equipment needed for setting up the propellant production site. This includes solar panels, communications gear, equipment for microwave power-beaming, a unit for electrolysis and refrigeration (hydrogen and oxygen are cryogenics, requiring very low temperatures to liquefy), rovers for the crew, robotic rovers, and a trailer for hauling raw materials. The second cargo lander will deliver the habitation module in which the crew will live and work, and will include food, tools, research equipment, extra spacesuits, and so forth.
After the cargo lands, tele-operated rovers will set up the solar and communications systems, connect the solar array to equipment that needs power, and install radio beacons for later missions. They will then be sent out to survey the area, taking detailed photographs that mission planners, scientists, and engineers back on Earth will use to plan the crewed missions, and that can be used to create a virtual reality environment on Earth that will allow millions of citizens to participate in the program, exploring alongside the astronauts as “ghost assistants.”
These two Falcon Heavy launches, costing $150 million each, will likely be all that is needed for transporting the base, as we will later show. But even if we have to add another launch or two, this only adds to the initial setup costs of Moon Direct and does not affect the recurring costs, which is where the overwhelming majority of an ongoing program’s expenses are incurred.

louis wrote:

A microwave power-beaming set up with a range of 100 kilometers??? We're nowhere near that are we?

LLO would be that distance but the panels are said to be on the surface. Ice is found at the bottom of craters but I think at the poles only...

Day time heating which lasts 2 weeks and would make it hard to cool the hydrogen but then again the lunar night will last 2 weeks as well to make it cold through with surface solar then you do not have power..

SpaceNut · 2018-08-12 19:07:20

Phase 2
Phase 2 will again require two launches. In the first launch, a Falcon Heavy takes another cargo lander, this time containing a fully fueled LEV, to low Earth orbit. In the second launch, a Falcon 9 delivers a crew to low Earth orbit in a Dragon 2 capsule to rendezvous with the LEV. The crew transfers into the LEV, and the cargo lander then takes the crew and the LEV to the Moon base. The Dragon 2 stays behind in low Earth orbit, and the LEV arrives on the Moon still fully fueled.
Once the crew arrives at the base, they finish setting it up and testing all its functions. The base relies on solar power, which needs to be beamed to the water mining site in a permanently shadowed crater (see illustration below). The main mission is to establish this site, to begin the mining operation with the help of rovers, and to transport the water in a trailer back to the base. There the crew will use the electrolysis and refrigeration unit to separate the water into hydrogen and oxygen and to liquefy the gases, then store them in tanks. (The tanks of previously delivered cargo landers would provide ample storage capacity.) The hydrogen and oxygen will later be used for rocket propellant and to supply fuel cells and oxygen for breathing, while unelectrolyzed water can be used to support other life support functions.
TNA56 - Zubrin ice mining 676w
Lunar Ice Mining
Microwaves, powered by solar arrays, are beamed from the top of the crater on the left through the transparent side of a half-aluminized tent at the bottom of the crater. The crater is permanently shadowed, and contains frozen water deposits in the soil. The microwaves are reflected into the soil, the microwaves heat up the soil, the water evaporates, and the vapor is extracted into a tank on a trailer, where it freezes.
After a few months of initial mining, exploring, and resource prospecting, the crew boards the LEV, still fueled from when it was delivered by the cargo lander, and returns to low Earth orbit, where it will rendezvous with a Dragon 2. This can either be the Dragon that took the crew to Earth orbit, or it can be another one that has been launched with a Falcon 9 to bring a replacement crew. Either way, the returning crew will transfer into the Dragon 2, which will serve as their re-entry capsule for the final leg of the journey back home.
The launch cost of each Phase 2 mission, requiring one Falcon 9 and one Falcon Heavy, will be $220 million. We will assume that two of these Phase 2 missions will be required to resolve the technical issues with getting lunar propellant production fully online. But we could easily plan for additional Phase 2 missions as needed.

RobertDyck wrote:

According to SpaceX website as of today. Falcon Heavy to LEO 63,800kg, to GTO 26,700kg, to Mars 16,800kg.

Not sure what to think of the space x numbers for the moon but that does not mean much if the tonnage is eaten up by the payloads and not giving it any ability to land.

GW ran the retropropulsion numbers for the crewed dragon (super Draco engines) and the fuel (2 T I think) was just able to land that capsule and truck but did not have any mass yet for landing legs.
The capsule was fully loaded and would total something close to the 12 ton mark.

SpaceNut · 2018-08-12 19:24:07

Phase 3
Once propellant production on the Moon is operational, the LEV can be reused. When a crew returns in the LEV to low Earth orbit, they can refuel the LEV and exchange with a new crew, which can use the LEV for the trip back to the Moon. Because refueling will now be available on the Moon, we will no longer need to launch fuel for the LEV to travel from the lunar surface to Earth, or a cargo lander system to deliver the LEV. The only mass that will need to be launched from Earth will be the crew in their capsule, and a tank to refuel the LEV just for the trip back to the Moon. Moreover, with propellant now available on the Moon, the LEV can be used not only to take crews back to Earth, but to explore the lunar surface itself.
Recall that the LEV requires 6 tons of propellant to perform its 6.1 km/s delta-V. SpaceX’s Falcon 9 launcher is capable of lifting 23 tons to low Earth orbit. This is more than enough to deliver a tank with enough propellant to refuel the LEV, plus a Dragon 2 capsule with a replacement crew. Thus, the recurring Moon mission could be done by means of a single Falcon 9 launch, which costs only about $70 million.
Furthermore, once the base is well established, there will be little reason not to extend lunar stays to four months or more. Again, if we use a common planning assumption that our mission’s total costs aside from the launcher — that is, the cost of the refueling tank, crew, cargo, and so on — will be roughly equal to the launch cost, we should be able to sustain a permanently occupied lunar base with just three $140-million missions annually. This is an ongoing yearly cost of around $420 million, or two percent of NASA’s current budget of about $20 billion.
We have focused on the Falcon 9 and Dragon 2 capsule, as these are the cheapest equipment and are already available or likely to be so soon. However, we should keep in mind that for recurring missions, if the Falcon 9 were to become unavailable, we could use the Atlas V, the Delta IV (not to be confused with delta-V), or the soon-to-be-built New Glenn or Vulcan. Also, if the Dragon needs to stand down, it could be replaced with the soon-to-be-built Orion (which would probably require a more powerful launcher than the Falcon 9), Boeing Starliner, or Sierra Nevada Dream Chaser. The architecture of our Moon transportation system is thus extremely versatile and robust.

Here are the 2 topics that are close to this topic and has the GW numbers with in them and or his website with them.

Apollo 8 redux which is the flyby mission

Apollo 11 redux go land sortie repeat

Once we have done the lifting and landing numbers we need to look at the remaining support items...

louis · 2018-08-12 21:42:13

Back in 2015 I think the record for microwave power-beaming was around half a kilometre...I don't think we've made that much progress in the last three years to beam energy over 100 kms. Not sure why Zubrin would be proposing this solution given the technology is not mature.

SpaceNut wrote:

louis wrote:
A microwave power-beaming set up with a range of 100 kilometers??? We're nowhere near that are we?
LLO would be that distance but the panels are said to be on the surface. Ice is found at the bottom of craters but I think at the poles only...
Day time heating which lasts 2 weeks and would make it hard to cool the hydrogen but then again the lunar night will last 2 weeks as well to make it cold through with surface solar then you do not have power..

RobertDyck · 2018-08-13 00:50:57

louis wrote:

Back in 2015 I think the record for microwave power-beaming was around half a kilometre...I don't think we've made that much progress in the last three years to beam energy over 100 kms. Not sure why Zubrin would be proposing this solution given the technology is not mature.

Dr. Zubrin pursued his life-long dream of becoming an aerospace engineer. He landed his dream job, worked for Martin-Marietta. Then the president ordered NASA to go to Mars. NASA blew that up with 90-Day-Report. Then he got a second chance, his employer ordered all engineers to come up with a practical plan for Mars. He did. He pitched it to NASA, lobbied NASA, got some influential individuals to support it. But Congress shot it down because they still suffered sticker-shock from the 90-Day-Report. He spent his entire life since trying to push this. Like Sisyphus, eternally pushing a bolder uphill, only to have it roll down when he nears the top. So perhaps Dr Zubrin decided to take a step back, to look at aerospace engineering again. The goal of Mars was chosen by President George H. W. Bush (#41). Perhaps he needs to stop pushing that goal, and choose something that has current support. Dr. Zubrin had argued against the Moon, but that was because the 90-Day-Report cost so much that Congress of 1989 and the '90s wouldn't pay that. If current Congress will, then let's do that. Besides, one argument against the Moon was lack of water. But they found water ice. Not much, arguably not concentrated enough to harvest, but if Congress and NASA are willing to pay to pursue that, then go with it. And Dr. Zubrin argued against solar power satellites, one big argument was microwave beaming doesn't work. But if he's going to stop pushing the bolder up hill, then go with that too. Embrace everything he previously argued against. After all, one major problem with microwave beaming is moisture in air either absorbing the beam or diffusing it. Another issue is particulates in air diffusing the beam. But the Moon has no atmosphere, so perhaps (just maybe) long distance microwave beaming could work. Again, the key feature is vacuum. Maybe. Maybe.
hE2F6E4E5

kbd512 · 2018-08-13 15:44:14

Does it strike anyone else as noteworthy that NASA has actually spent all the money requested in the 90 day report and more since that time and we still haven't gone anywhere outside of LEO?

louis · 2018-08-13 16:10:54

Yep, I've often thought about that. Add up the cost of all the robot missions outside LEO, you'd definitely have enough money to get to Mars. I've said before and will say again that within one year of getting humans on Mars we will learn more about the planet than in the previous 50 years of missions.

kbd512 wrote:

Does it strike anyone else as noteworthy that NASA has actually spent all the money requested in the 90 day report and more since that time and we still haven't gone anywhere outside of LEO?

louis · 2018-08-13 16:50:06

Helpful discussion of microwave/laser power beaming...

https://space.stackexchange.com/questio … ough-space

It doesn't seem this technology is anywhere near to close to being able to transfer power reliably over 100 Kms.

Why is that solution required? You can produce plenty of power during the 14 days of continuous sunlight with PV panels on the lunar surface.

With perhaps 100 tonnes or more of supplies being delivered to the lunar surface, you don't really need to source water for your lunar mission (this is the difference from Mars, since there is no need to produce propellant on the surface). 10 tonnes of water would provide for all the needs of a 10 crew mission for a year without any water recycling - but of course, you can have water recycling, to ensure that water lasts even longer.

20 tonnes of battery storage at 250 Whs per Kg would give you about 15Kws of continuous power during the 14 days of darkness.

That could be supplemented by an emergency hydrocarbon/oxygen system.

A lightweight PV panel system that would meet the needs of a 10 person colony would probably weigh in at less than a couple of tonnes.

Here's a BFR Lunar simulation.

https://www.youtube.com/watch?v=4yC3LjKfrUM

Once you've got your base established and more supplies come in, you can then set up a robot mining mission at the poles, even if your base is hundreds of miles away - the solution is to have a continuous "conveyor belt" of automated rovers shuttling between the base and the ice mine. PV powered rovers, recharging at solar power stations along the way could easily bring in a couple of tonnes of ice per journey.

For me a lunar base will primarily have a commercial tourism role to play, coupled with science research. There is not much need or point in attempting to set up a complex industrial infrastructure on the Moon, given how very close it is to Earth.

SpaceNut · 2018-08-13 18:31:57

Production Requirements
We will next consider the crucial question of whether a crew could produce enough propellant, oxygen, and electricity on the Moon at a fast enough rate to sustain the recurring Phase 3 missions. We need to produce liquid hydrogen and oxygen for propellant; oxygen for crew consumption; and power for extracting water from lunar soil, splitting it into hydrogen and oxygen, and cooling these gases into liquids. Additional water can be used for life support, supplementing water recycled from consumables.
First we will consider propellant production. Each Moon Direct mission requires 6 metric tons of propellant to be made on the Moon for the LEV’s flight back to Earth orbit. It also requires 6 tons of propellant for each long-distance surface sortie from the base to a distant location on the Moon and back. For purposes of analysis, we will assume that once the base is operational, every fourth month there will be a round-trip mission from the Moon to Earth to exchange crew, and in each other month there will be one long-range exploration flight. The propellant manufacturing requirement will therefore be 6 tons per month, or 200 kilograms per day.
Engines running on liquid hydrogen and liquid oxygen use a higher ratio of hydrogen to oxygen than what is found in water. To get our 200 kilograms of propellant, we would need to electrolyze around 260 kilograms of water (about 70 gallons) per day. The happy side effect is that this would leave about 60 kg of leftover oxygen every day, which could be used for crew breathing supply.[5]
The dominant power requirement will be for vaporizing and electrolyzing the water. To electrolyze 260 kg of water per day will require 56 kilowatts of power.[6] We can estimate that water could be vaporized at the same rate using beamed microwaves with about 26 kilowatts of power.[7] Cryogenic liquefaction of the hydrogen and oxygen products — aided by the extremely cold temperatures on the Moon — will add about 25 kilowatts, and life support and other equipment will also add another 13 kilowatts to the power needs, so we can estimate 120 kilowatts for our total power requirement. This could be supplied by either a solar array or a nuclear reactor; for either alternative we estimate a mass of around 4 tons using proposed technologies.[8]
Learning about how easily we can harvest resources on the Moon is a central reason for creating a human exploration program in the first place. It will be the task of the first crew members on the Moon to discover some of the details about water extraction and electrolysis that we don’t yet fully know — especially the precise concentrations of water present in the soil of the permanently shadowed craters.
But we already know that water is fairly plentiful in lunar craters, enough so to make propellant production feasible. A 2015 study in Icarus estimates that water ice is present in concentrations of 0.1 to 1 percent in the visible surface layer (the first few millimeters of soil) of craters near the south pole. Higher concentrations may also be available beneath the surface. When NASA’s 2009 LCROSS mission crashed a projectile into a crater near the south pole, spectral analysis on the resulting dust plume found water ice concentrations of 3 to 9 percent in soil just a few meters below the surface. Most strikingly, in August, just as this article went to publication, a study published in the Proceedings of the National Academy of Sciences offered the most reliable evidence to date by using measurement techniques definitively able to distinguish water from similar molecules. The study, which measured the visible surface of polar craters, found that in some areas water concentration reaches 30 percent by weight.
There are uncertainties in the total mass required for operating lunar ice harvesting end to end. But we won’t know until we go. Perfecting the techniques for finding, extracting, and electrolyzing ice to produce fuel and oxygen will be a significant but surmountable challenge for the first lunar explorers. Although there are already promising schemes for lunar resource utilization, some trial and error under the actual conditions will inevitably be needed to work out the kinks. This is the reason to send human explorers and not robots. The water is there. The light from the Sun is there to power the transformation of water into breathable oxygen and usable rocket fuel. What isn’t there yet is the most valuable resource of all: human ingenuity.

BFR is not part of this discussion, lets stay focussed on inital post please and I would also add that Nasa constellation work would also not be as they were looking at a nuclear powering option.

Mission 1
Batteries on the moon swelter in the heat and then in the cold so they will need to be burried in order to keep them climate controled.
Much like the batteries the electrolysis process and liquification will need to be underground as well to climate control what happens. Its one thing to make use of heat exchanges and radiators that can be switched on and off as required to make use of the lunar cycle but its that distance between each that makes it harder for man to do.

Solar panel materials will need to be proved out that they can withstand the temperature swings.

High speed communication not truely defined enough as to type.

The telerobotic rovers and the trailers need more details of tonnage plus power capacity.

The end round up of features are about planning for a future landing.

Mission 2 & 3 should be co-missions as you want the food and supplies to be with the crew to keep it fresh for eating and not needing more water for freezed dried...

SpaceNut · 2018-08-13 19:02:04

Comparison of Mission Modes
Now that we know that Moon Direct is possible and sustainable, we can compare it to alternative plans for a lunar base. We have already discussed some of the advantages of Moon Direct over NASA’s Lunar Orbital Platform-Gateway, and we can now look at the numbers to confirm this, assuming the gateway were used as a base for lunar exploration. We will consider five different mission modes, including Moon Direct. For the sake of getting an overall sense of our program, we will assume that each mode, after bringing propellant production online, will include twenty recurring crewed missions — about seven years’ worth. The most important points of comparison are the total mass that has to be lifted into low Earth orbit — a good indicator of a program’s overall costs — and the portion of the lunar surface we can explore with round trips of a lunar lander once propellant production is operational (see Table 2, appendix).
Our first option is an applied version of the current NASA program of record. It requires setting up the Lunar Orbital Platform-Gateway prior to any human-piloted missions to the surface of the Moon. Since the gateway actually serves no useful function, it is not surprising that this bizarre plan turns out to be the worst for sustaining a lunar base. The total mass to be lifted into low Earth orbit would be 2,750 tons, and only about 3 percent of the Moon’s surface would be available in a round trip mission of a lunar lander.
The next two options are progressively more rational, if less imaginative. Essentially, they duplicate the lunar orbit rendezvous mission plan that provided the basis of the Apollo program, but they execute it mostly with current hardware. The only difference between these two plans is that, to stay in lunar orbit, one plan uses the massively overweight Orion capsule to take the place of the Apollo Command and Service Module or the lunar gateway, while the other plan employs the much lighter Dragon. (NASA designed the Orion too heavy to launch to orbit on an Atlas V, thereby creating the need for its hoped-for Ares I launch vehicle. This was not a good idea. It resulted in a wildly suboptimal Orion, and President Obama canceled the Ares I anyway.)
So, if you wish to copy Apollo’s lunar orbit rendezvous plan, using a Dragon is the way to go. But, as noted earlier, while lunar orbit rendezvous is quite serviceable for Apollo sortie missions, it has issues when applied to the operation of a permanent lunar base. The Orion-based plan requires lifting over 2,300 tons to low Earth orbit, an improvement over using the gateway, but still unattractive. The Dragon-based plan requires just under 1,000 tons. Both options still give you access to only 3 percent of the Moon’s surface on round-trip sorties.
For supporting a Moon base, a mission mode based on direct return from the surface to Earth would be preferable. There are two ways this could be done. The simplest, which is our fourth option, would be to take off from the lunar surface in a capsule, fly straight back to Earth, directly enter the atmosphere, pop a parachute, and land. The problem with this plan, however — and the reason it was not employed in Apollo — is that it requires taking a heavy capsule all the way to the Moon, landing it there, and then lifting it again to shoot it back home. Attempting this with an ultra-heavy Orion would be absurd. Even doing it with a much lighter Dragon, as presented in our fourth option, requires 1,600 tons, significantly more than using the Dragon for lunar orbit rendezvous — although the difference becomes modest for the recurring mission. It would also make less than 1 percent of the lunar surface available for exploration.
But there is, of course, another way to do a direct-return mission. Our final option is Moon Direct, in which we leave the Dragon capsule in low Earth orbit and only go to the Moon and back in a much lighter Lunar Excursion Vehicle. Because it has no heat shield and can’t use the atmosphere as a brake, the LEV needs to use its propulsion system to slow it down to enter into low Earth orbit, so its return delta-V is 6.1 km/s instead of the 3 km/s required for the other mission modes. But because its dry mass is just a quarter of the Dragon’s, total mass requirements for this mode turn out to be much lower than a Dragon direct return or any other mode — a little over 500 tons.
Furthermore, the LEV’s delta-V provides an entirely new capability that all the other mission options lack: global mobility on the Moon. To put this in perspective, if you land at the North Pole on Earth and can travel to a quarter of the global surface, you could get to Houston, Shanghai, or Cairo and back. At three or one percent of the surface, you’d only make it part of the way to the Arctic circle.

Mission 2 the habitat we do not have let alone a means to land it on the moon.
Quick disconnect connect feature to power should not be much of a design issue.
The habitat science lab equipment and what we will do with it needs more information.

Mission 3 we still need to either revive the lunar lander or design a new means to get a crew to the surface and back to orbit.

Mission return home seems to have no means to return home as there is nothing in orbit and a lunar lander can not do so back to the waiting dragon inLEO.

https://www.teslarati.com/spacex-crew-d … t-gallery/

louis · 2018-08-14 04:39:17

I was just critiquing some of the mission assumptions:

1. Why choose an unproven and immature technology like microwave power beam transmission for such a crucial part of the mission (energy)?

2. Why is water sourcing so important when you don't need produce propellant on the Moon and you can ship it in and preserve much of it through water recycling?

3. The moon is close by - just 4 days away, less time than it took people to get from Europe to the USA in pre-aviation days.

I am really struggling to believe there would be any problem with operating PV panels or batteries on the moon. With reflective material and use of materials like aerogel, plus aircon plus simple regolith cover I doubt we would have any problem with temperature insulation. There is no atmosphere to conduct heat on Mars is there?

SpaceNut wrote:

BFR is not part of this discussion, lets stay focussed on inital post please and I would also add that Nasa constellation work would also not be as they were looking at a nuclear powering option.
Mission 1
Batteries on the moon swelter in the heat and then in the cold so they will need to be burried in order to keep them climate controled.
Much like the batteries the electrolysis process and liquification will need to be underground as well to climate control what happens. Its one thing to make use of heat exchanges and radiators that can be switched on and off as required to make use of the lunar cycle but its that distance between each that makes it harder for man to do.
Solar panel materials will need to be proved out that they can withstand the temperature swings.
High speed communication not truely defined enough as to type.
The telerobotic rovers and the trailers need more details of tonnage plus power capacity.
The end round up of features are about planning for a future landing.
Mission 2 & 3 should be co-missions as you want the food and supplies to be with the crew to keep it fresh for eating and not needing more water for freezed dried...

SpaceNut · 2018-08-14 21:19:22

Range and Fraction of Moon Accessible with LEV
If we assume, as is typically the case, that there are 10% delta-V losses incurred fighting gravity during takeoff or landing on each burn,[9] the real velocity V per burn achievable for a LEV with a total delta-V capability D that is divided among four burns is given by:[10]
V = 0.9 D / 4
The maximum range of a projectile fired with velocity V, on a spherical airless planet with radius R, where the velocity of a zero-altitude orbit around that planet is W, is given by:
Maximum range = 2R sin-1 [ (V2/W2) / (2 – V2/W2) ]
On the Moon, W = 1680 m/s and R = 1737 km.[11] Combining the two equations, the range of the LEV used as an excursion vehicle is shown in Figure 1. We can see that a LEV with a delta-V capability of 6.1 km/s provides substantial global access on round trip missions — a range of 1,823 km, or 25% of the surface. And it provides 100% global access on one-way missions, with substantial fuel to spare.[12] One-way trips would allow the LEV to, for example, go from one polar base to another base on the opposite pole.

Daytime on one side of the moon lasts about 13 and a half days, followed by 13 and a half nights of darkness. When the sunlight hits the moon's surface, the temperature can reach 253 degrees F (123 C). The "dark side of the moon" can have temperatures dipping to minus 243 F (minus 153 C).

https://www.forbes.com/sites/brucedormi … 4c83d57439

http://blogs.discovermagazine.com/crux/ … 3OXZDVIrGg

louis · 2018-08-15 08:17:51

Well - the Apollo landers haven't melted yet...

I don't think the temperature range is a serious impediment to setting up a base.

SpaceNut wrote:

Daytime on one side of the moon lasts about 13 and a half days, followed by 13 and a half nights of darkness. When the sunlight hits the moon's surface, the temperature can reach 253 degrees F (123 C). The "dark side of the moon" can have temperatures dipping to minus 243 F (minus 153 C).
https://www.forbes.com/sites/brucedormi … 4c83d57439
http://blogs.discovermagazine.com/crux/ … 3OXZDVIrGg

GW Johnson · 2018-08-15 13:22:20

There is no ambient temperature on the moon (or any airless world) any more than in airless space. There are only the temperatures of objects being bathed in sunlight or shadow, and radiating to some combination of the materials around them, and space.

It is rocks with a certain range of visible reflectance and infrared emissivity that reach 250-ish F in sunlight or -240-ish F in shadow on the moon.

The spectral reflectivity and emissivity of aluminum is different from rocks, which is why the Apollo landers did not get that all hot or cold on the moon, and so were not weakened by over-hot material temperatures in the portions exposed to sunlight, or excessive cold brittleness in the shaded portions.

Very special attention must be paid to spectral characteristics of surface materials and coatings, in order to achieve this result. It is not a trivial design issue.

These thermal equilibria usually obtain within a few hours at most. The day/night length on the moon is quite long in comparison. Solar panels must accommodate the same thermal equilibria, but you are without generating capability for 13+ days worth of continuous night, meaning you need either gigantic batteries, some sort of fuel-based power, or else atomic power.

THAT is why the Apollo landing zones were all situated in daylight only. That is also what the Kilopower nuclear Stirling generator developments are all about.

Mars does indeed have an atmosphere so that there really is an ambient temperature. But it is a very thin one, first cousin to the vacuum of space at 0.007 times Earth sea level density. Heat transfer coefficients for convection scale roughly as density raised to the 0.8 power. So, conduction and radiation heat transfer dominate the Martian picture far more than convection, unlike here on Earth. But, it's not zero convection, either, the way it is in space or on the moon.

GW

SpaceNut · 2018-08-15 19:34:54

Mass and Payload of LEV
In Figure 2 we show the LEV’s required wet mass (or total mass), propellant mass, and inert mass (tanks, engines, and other propulsion structures), and the available payload mass, as a function of its total delta-V capability.
The LEV’s liquid oxygen/hydrogen (LOX/H2) propulsion system is assumed to have a specific impulse of 450 seconds. Informally, specific impulse is a measure of a propulsion system’s efficiency — its “gas mileage.” Formally, the specific impulse measures how much change in momentum (or how much impulse) a rocket system can attain for a given amount of propellant, usually calibrated assuming the rocket is operating in a vacuum. For example, a rocket system that required 2,500 pounds of propellant to deliver 10,000 pounds-force of thrust for 100 seconds would have a specific impulse of 10,000 pounds-force * 100 seconds / 2,500 pounds = 400 seconds. (A pound-force is the amount of force exerted by Earth’s gravity on a pound of mass.) One way of understanding why the unit of specific impulse is seconds is that it measures for how many seconds the rocket system can use a pound of propellant to deliver a pound-force of thrust.
As shown by Russian space pioneer Konstantin Tsiolkovsky in 1903, we can derive a rocket’s required wet mass (Mwet) from its dry mass (Mdry), its specific impulse (Isp), its delta-V capability, and standard gravity (g0, a constant value required for unit conversion, calibrated by using Earth’s gravitational constant, 9.8 m/s2, as standard). The equation is as follows:
Mwet = Mdry exp ( delta-V / Isp g0 )
The dry mass of the LEV, which we have assumed will be 2 metric tons, will be divided between the payload and the various structures directly required for propulsion — the engines, fuel tanks, rocket structure, and various other supporting equipment. These latter structures are collectively called the inert mass, since they are neither propellant nor payload, but must come along for the ride. The required inert mass will increase as we need to carry more propellant. We will assume that the inert mass will increase proportionally to the mass of the propellant, requiring a mass equal to 11% of the propellant mass. With a denser propellant such as LOX/CH4, the ratio might be about 7%.[13]
Here is an example of how we’d calculate our required wet mass, propellant mass, and inert mass, and finally our available payload mass, at a delta-V of 6.1 km/s:
First, we use Tsiolkovsky’s equation to calculate our required wet mass:
Mwet = (2,000 kg) * exp ( 6100 m/s / (450 s * 9.80665 m/s2) ) = 2,000 kg * 3.984 = 7,968 kg
Of this total mass, we have assumed that 2 tons will be dry mass, leaving 5,968 kg of required propellant.
If we assume the tanks, engines, and other propulsion structures have a combined mass equal to 11 percent of the propellant, then 656 kg of the 2,000-kg dry mass must be employed for such purposes, leaving us 1,344 kg for the crew compartment and cabin payload.
Examining Figure 2, we see that the critical 6.1 km/s delta-V performance point, needed to achieve either direct return from the Moon to LEO or global mobility on the Moon, is readily achievable with 8 tons of total mass.

This seems to have also been over looked in that Space Radiation Devastated the Lives of Apollo Astronauts. 07/28/16 New research points to serious concerns about human survival during deep space travel.

The study compared the mortality rates of lunar astronauts who have passed away to astronauts who never flew and to those who have only made it to orbit.
The number of cardiovascular disease-related deaths among the deep space astronauts were significantly higher.
The rate among astronauts who never flew is 9%. Among low-Earth orbiting astronauts, its 11%. For the men who travelled to the Moon, a staggering 43%, or 4-5 times higher than their less-travelled colleagues.The one exception to the study was Apollo 14 astronaut Edgar Mitchell, who passed away after the study’s data had already been collected.
Researchers also exposed mice to a similar type of radiation and after six months, the mice demonstrated sustained cellular breakdown and impairment of the arteries—which, in the human body, leads to cardiovascular disease. “What the mouse data show is that deep space radiation is harmful to vascular health,” said Delp.
These revelations pose tough questions for NASA and the firms from the agency’s NextSTEP program that are bidding to build a habitat that can protect humans during long-duration spaceflight.

I recall seeing images ofan astronauts foot and the big toe that had seen a bit of what appeared to be frostbite from the outing on the moon but could not seem to find them...

http://www.spiegel.de/international/wor … 37327.html

https://www.satra.com/bulletin/article.php?id=1746]The first steps on Mars?

Exploring the requirements for boots that may be worn on future missions to one of our closest neighbours.

Void · 2018-08-15 20:25:58

I would ask that we be considering other factors in such a measurement. Sure radiation is almost completely bad, except for the spectrum that works for us.

However, these Men were selected to be of a certain type. The candle which burns brightest, might burn out sooner.

Not sure that that is part of the answer, radiation damage is bad, but this other aspect perhaps should be considered.

https://www.youtube.com/watch?v=wRxHYHPzs7s

https://www.goodreads.com/quotes/90347- … ns-half-as

But we must consider magnetic and mass methods of blocking radiation.

Also genetic engineering.
https://www.indiatimes.com/technology/s … 76002.html

Done and fun.

Last edited by Void (2018-08-15 20:32:27)

GW Johnson · 2018-08-15 20:37:47

GCR varies more-or-less sinusoidally from a min of 24 REM in a year to a max of 60 REM in a year, on a roughly 11 year period (matching the solar activity cycle). Max GCR occurs during solar activity minimum. For comparison, the max limit for astronauts is 50 REM in a year, 25 REM max in any one month, and a career limit that varies with age and gender, but maxes out at 400 REM in a lifetime. Those limits are roughly twice the limits for an Earthly nuclear worker.

The astronaut exposure limits were calculated for an estimated cancer risk increase of 3% over civilians. Maybe that calculation is no good, and maybe it really is good. You can find articles and papers that say pretty much anything. I got the quoted numbers off the NASA radiation website. They list lots of references, not just a few. So I tend to think they are fairly reliable.

However, the link between radiation and circulatory disease is a surprise. I had not heard that before.

It is the GCR (and to a small extent the exposure crossing the Van Allen belts) that the lunar astronauts were exposed to. I do not know if they saw 24 vs 60 REM/year rates. What they were NOT exposed to was a solar flare event. If such had occurred, they would have died in a matter of hours. Such can range from 100's to 10,000's of REM per HOUR. The nominal figure of merit for a fatal dose is 50-to-100 REM in a "short time" (minutes to hours).

The GCR is the really high-energy radiation type, but it is a very slow drizzle. Solar flare radiation is far lower energy and less penetrating, but there is typically a truly enormous flood of it during any given event.

According to the NASA radiation site, the same 15-20 cm of water that makes a big flare survivable also cuts the GCR by a significant fraction (from 60 REM/yr down to nearer 50 REM/year). Thicknesses vary for water vs aluminum vs hydrogen, but all three are in the same general thickness class: near 15-20 cm. A spacecraft hull at 0.05 to 0.10 inch thick aluminum might as well not be there at all, radiationally speaking.

GW

Last edited by GW Johnson (2018-08-15 20:45:39)

louis · 2018-08-16 03:13:20

I think if you read Tom Wolfe's wonderful book "The Right Stuff" you can see that the astronauts who got chosen for the toughest missions were amongst the most hard-living, hard-drinking, most driven types...

Void wrote:

I would ask that we be considering other factors in such a measurement. Sure radiation is almost completely bad, except for the spectrum that works for us.
However, these Men were selected to be of a certain type. The candle which burns brightest, might burn out sooner.
Not sure that that is part of the answer, radiation damage is bad, but this other aspect perhaps should be considered.
https://www.youtube.com/watch?v=wRxHYHPzs7s
https://www.goodreads.com/quotes/90347- … ns-half-as
But we must consider magnetic and mass methods of blocking radiation.
Also genetic engineering.
https://www.indiatimes.com/technology/s … 76002.html
Done and fun.

Last edited by louis (2018-08-16 14:17:12)

louis · 2018-08-16 03:22:20

Wasn't the lunar module little better than a tin can? I would hope we could seriously improve on radiation protection offered on Apollo Missions. Another area to look at is lunar dust inhalation...wasn't that a serious issue ie dust contamination within the module.

SpaceNut wrote:

This seems to have also been over looked in that Space Radiation Devastated the Lives of Apollo Astronauts. 07/28/16 New research points to serious concerns about human survival during deep space travel.
The study compared the mortality rates of lunar astronauts who have passed away to astronauts who never flew and to those who have only made it to orbit.
The number of cardiovascular disease-related deaths among the deep space astronauts were significantly higher.
The rate among astronauts who never flew is 9%. Among low-Earth orbiting astronauts, its 11%. For the men who travelled to the Moon, a staggering 43%, or 4-5 times higher than their less-travelled colleagues.The one exception to the study was Apollo 14 astronaut Edgar Mitchell, who passed away after the study’s data had already been collected.
Researchers also exposed mice to a similar type of radiation and after six months, the mice demonstrated sustained cellular breakdown and impairment of the arteries—which, in the human body, leads to cardiovascular disease. “What the mouse data show is that deep space radiation is harmful to vascular health,” said Delp.
These revelations pose tough questions for NASA and the firms from the agency’s NextSTEP program that are bidding to build a habitat that can protect humans during long-duration spaceflight.
I recall seeing images ofan astronauts foot and the big toe that had seen a bit of what appeared to be frostbite from the outing on the moon but could not seem to find them...
http://www.spiegel.de/international/wor … 37327.html
https://www.satra.com/bulletin/article.php?id=1746]The first steps on Mars?
Exploring the requirements for boots that may be worn on future missions to one of our closest neighbours.

GW Johnson · 2018-08-16 10:39:44

I think the astronaut pressure cabin on the Apollo LM was something like 0.020 inch think aluminum sheet. Parts of it were covered with a blanket that had an aluminum foil outer layer for reflectance, plus some insulation.

GW

Oldfart1939 · 2018-08-16 12:19:05

The LEM would be envious of a well-constructed tin can.

New Mars Forums

Announcement

#1 2018-08-12 16:03:51

Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#2 2018-08-12 16:18:46

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#3 2018-08-12 16:46:14

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#4 2018-08-12 18:34:50

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#5 2018-08-12 19:00:04

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#6 2018-08-12 19:07:20

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#7 2018-08-12 19:24:07

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#8 2018-08-12 21:42:13

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#9 2018-08-13 00:50:57

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#10 2018-08-13 15:44:14

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#11 2018-08-13 16:10:54

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#12 2018-08-13 16:50:06

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#13 2018-08-13 18:31:57

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#14 2018-08-13 19:02:04

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#15 2018-08-14 04:39:17

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#16 2018-08-14 21:19:22

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#17 2018-08-15 08:17:51

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#18 2018-08-15 13:22:20

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#19 2018-08-15 19:34:54

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#20 2018-08-15 20:25:58

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#21 2018-08-15 20:37:47

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#22 2018-08-16 03:13:20

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#23 2018-08-16 03:22:20

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#24 2018-08-16 10:39:44

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

#25 2018-08-16 12:19:05

Re: Dr. Robert Zubrin Moon Direct: How to build a moonbase in four years

Board footer