How to Fix the US moon program

The Trump administration has said America should return to the Moon and build permanent bases. Robert Zubrin points out (in an article at New Atlantis) that this stated goal has not received any meaningful funding. The New Atlantis article by Robert Zubrin has an updated write up of his Moon Direct program proposal.

The Lunar Orbital Platform-Gateway (formerly known as the Deep Space Gateway) is receiving some money. The gatewate will be a waste.

The gateway is a planned space station that will orbit the Moon, supposedly serving as an outpost for human explorations to the Moon, Mars, and deep space.

NASA says Orion would take its first crew around the Moon by 2023. Vice President Pence has recently stated a goal of putting astronauts on the gateway by the end of 2024.

The lunar gateway idea is silly. There is no need to have a space station circling the Moon in order to go to the Moon or Mars or anywhere else. And there is not much research worth doing in lunar orbit that can’t already be done on the International Space Station, in Earth orbit, or with lunar probes and robots.

NASA claims the gateway would create an opportunity
* to test state-of-the-art propulsion, communication, and other technologies at a greater distance from Earth
* tele-operated rovers could be sent from the gateway to the Moon
* planets and stars could be observed from a different vantage than from the ISS or current telescopes.

None of these activities requires human presence in lunar orbit. These are not reasons for having a gateway, but rationalizations.

We don’t need a space station in lunar orbit — but we could use a base on the Moon itself. A Moon base would be much more than a stopping point; it could also be a site for producing hydrogen–oxygen rocket propellant from water on the Moon. This is a powerful propellant that has been a mainstay of rockets for decades, used by the Saturn V and the space shuttle.

Some areas on the moon have water ice concentrations of 30 percent by weight in the topmost layer of soil.

PNAS – Direct evidence of surface exposed water ice in the lunar polar regions

The moon is a world with a surface area larger than the continent of Africa. Its terrain is rough, roadless, and riverless, so astronauts cannot effectively explore it using surface vehicles. Lunar explorers are going to need to fly.

It is theoretically possible that multitudes of locations on the Moon could be visited by launching scores of missions directly from Earth, the cost of doing this would be astronomical. We need to create a base that can produce propellant on the Moon. Moon missions need to fueled and operated on the moon. Only occasional missions from Earth are needed to resupply consumables and switch out crews.

Where should such a base be located? The Moon’s poles are ideal not only because they have nearby permanently shadowed craters with water, but because they also feature near-permanently illuminated highlands offering reliable access to solar energy. The poles are thus the clear favorites for a base, as they provide both the raw material and the energy source necessary to manufacture hydrogen–oxygen rocket propellant.

Producing water and fuel on the moon

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.

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. We can estimate that water could be vaporized at the same rate using beamed microwaves with about 26 kilowatts of power. 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.

Moon Direct

Moon Direct requires relatively little launch mass and largely uses existing technologies.

Following our assumption that launch costs and non-launch costs will be roughly equal, we could execute our setup missions (two flights for Phase 1 and two Phase 2 missions) for about $1.5 billion. Recurring missions will cost $420 million per year. This is two percent of NASA’s current budget. This is very inexpensive by the standards of human space programs. NASA’s human spaceflight program total budget is currently around $10 billion per year with little clear purpose.

44 thoughts on “How to Fix the US moon program”

  1. Seriously, you’re going to have to get better about quotation marks and attribution, or one of these days you’re going to lose a lawsuit over plagiarism.

    Reply
  2. It is theoretically possible that multitudes of locations on the Moon could be visited by launching scores of missions directly from Earth, the cost of doing this would be astronomical. “Well yes. By definition.

    Reply
  3. You have to look at this in terms of the technology needed for each solution. If you have:1) Ability to launch cryogenic prop from Earth.2) Moderately long cryogenic stage life (5-14 days).3) On-orbit refueling and assembly technology….then you have what’s needed for distributed launch from LEO. That’s plenty to get to the Moon.To make an NRHO station worth building, you also need:4) ISRU water mining from the Moon.5) Robust water launch to NRHO, with the ability to land the empty water tanker back on the Moon.6) Ability to electrolyze water to hydrolox.7) Much longer cryogenic storage life (SWAG: 3 months?)The problem with LOP-G isn’t that it’s useless forever, it’s just that it’s not very useful in the early parts of a lunar campaign. The proper approach is to develop on-orbit refueling of long-life stages in LEO and use that to get your lunar surface infrastructure built. After that, we can look at LOP-G. But building it first is silly (and only is being proposed because it gives SLS something plausible to do).

    Reply
  4. You have to look at this in terms of the technology needed for each solution. If you have:

    1) Ability to launch cryogenic prop from Earth.
    2) Moderately long cryogenic stage life (5-14 days).
    3) On-orbit refueling and assembly technology.

    …then you have what’s needed for distributed launch from LEO. That’s plenty to get to the Moon.

    To make an NRHO station worth building, you also need:

    4) ISRU water mining from the Moon.
    5) Robust water launch to NRHO, with the ability to land the empty water tanker back on the Moon.
    6) Ability to electrolyze water to hydrolox.
    7) Much longer cryogenic storage life (SWAG: 3 months?)

    The problem with LOP-G isn’t that it’s useless forever, it’s just that it’s not very useful in the early parts of a lunar campaign. The proper approach is to develop on-orbit refueling of long-life stages in LEO and use that to get your lunar surface infrastructure built. After that, we can look at LOP-G. But building it first is silly (and only is being proposed because it gives SLS something plausible to do).

    Reply
  5. I think that as long as NASA stays out of the launch business, that happens pretty naturally.Ten years ago, this would have been impossible, because a huge chunk of the value in NASA missions was tied up in launch services. But, as a percentage of mission cost, launch has already declined precipitously, and is obviously set to decline still further.

    Reply
  6. I like this idea but give the big 4 the contracts to inspace infrastructure such as tugs depots and habitats and fund spacex via the postal service. Buy 100 BFR per year prepurchased for a decade at a time.

    Reply
  7. The problem with this is that “fixing” the lunar program is more of a political task than a technical one.My preferred strategy here is to offer the Big 4 (Boeing, Lockmart, Northrup-Grumman, and Aerojet-Rocketdyne) about the same amount of pork they’re getting from SLS and Orion, but targeted at a reasonable distributed launch capability.The biggest problem with the Zubrin plan isn’t technical. Its problem is that it requires putting a gun to the head of the Big 4 and blowing their brains out, just to give the keys to the kingdom to SpaceX. That’s simply not going to happen.Furthermore, if you gave the keys to the kingdom to SpaceX, they’d soon be a nasty and inefficient as the Big 4 are. There’s really a very large advantage to divvying this stuff up amongst the various players, because they will compete viciously with each other. The competition isn’t so much for the NASA chunks of the architecture, but for the huge land-rush that will occur once the NASA infrastructure is in place enough to facilitate all the commercial guys coming in to exploit it.

    Reply
  8. Find an economical reason to go to the moon. Send a high resolution ore prospector to map the lunar surface from a very low orbit. Then send a few rover to validated its findings. Finding high concentrations of platinum metal ore should be enough economical incentive.

    Reply
  9. Bingo. The Gateway doesn’t have an essential purpose until you can send water from the lunar surface to it. Then it has very nice properties in terms of the orbital economics.

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  10. 1. Propellant depots orbiting at LEO and NRHO can be continuously supplied with propellant or water, for the production of propellant, from commercial launches from Earth from both large and small vehicles. Any commercial launch vehicle that was capable of deploying a satellite to geosynchronous orbit could easily deploy water or propellant to an NRHO depot. 2. Reusable LOX/LH2 spacecraft such as Lockheed Martin’s notional reusable lunar crew lander or the ULA’s reusable ACES derived lunar landers could transport crews from NRHO to the lunar surface in just 12 hours. And such vehicles would be able to return to an NRHO outpost within 12 hours. 3. Such reusable vehicles could also transport crews from LEO to NRHO and from NRHO and back. So only the simplest commercial launch vehicles would be required to transport crews to LEO ( the Falcon 9, Vulcan, and New Glenn) in order to to reach the the lunar surface. 4. For interplanetary travel, an NRHO departure shaves off about 2.7 km/s of delta v requirement relative to LEO departures.5. LEO departures for interplanetary space travel not only requires the supply of propellant from the Earth’s deep gravity well but also a substantial tonnage of water for drinking, food preparation, hygiene, air production, and radiation shielding requiring a delta-v of at least 9.3 km/s. 6. NRHO departures for interplanetary space would only require the supply of propellant and water from the Moon’s gravity well, requiring a delta-v of only about 2.52 km/s. Water and propellant requirements for interplanetary journeys would be substantially more massive than the dry weight of the vehicle— especially when departing from LEO. 7. NRHO is probably a good place to test simple rotating artificial gravity habitats needed to safely transport humans on interplanetary journeys that will probably take at least several months to a few years to complete. The station keeping requirement at NRHO are similar to those at LEO and short duration test flights to Sun Earth Lagrange points should be relatively easy to conduct from there. The only problem with a NRHO gateway, IMO, will be the temptation by NASA to make the habitat a lot more expensive and complex than it should be. The NRHO gateway simply needs to be a radiation shielded docking port for reusable vehicles traveling between the lunar surface and NRHO and traveling between LEO and NRHO. If its derived from the SLS propellant tank architecture, it would be easy to appropriately shield such a gateway from the heavy nuclei component of cosmic radiation and from major solar events with just twenty to thirty centimeters of water.

    Reply
  11. It’s a great location for a refilling station, but you want to build that station *after* you have access to (comparatively) cheap mass from the Moon for shielding. The Moon comes first. Otherwise the complaint about unnecessary radiation exposure is valid.And LEO, within the Earth’s magnetic protection, is the place to do the initial rotating habitat work. No need to deal with the radiation issue at the same time, and we want that work done before we build the lunar orbital.

    Reply
  12. A Lunar Orbital Gateway is also a good spot for testing, especially components and systems that will need to support life in the path of cosmic rays/solar particle events for months/years with minimal maintenance.

    Reply
  13. I think that as long as NASA stays out of the launch business, that happens pretty naturally.

    Ten years ago, this would have been impossible, because a huge chunk of the value in NASA missions was tied up in launch services. But, as a percentage of mission cost, launch has already declined precipitously, and is obviously set to decline still further.

    Reply
  14. I like this idea but give the big 4 the contracts to inspace infrastructure such as tugs depots and habitats and fund spacex via the postal service. Buy 100 BFR per year prepurchased for a decade at a time.

    Reply
  15. The problem with this is that “fixing” the lunar program is more of a political task than a technical one.

    My preferred strategy here is to offer the Big 4 (Boeing, Lockmart, Northrup-Grumman, and Aerojet-Rocketdyne) about the same amount of pork they’re getting from SLS and Orion, but targeted at a reasonable distributed launch capability.

    The biggest problem with the Zubrin plan isn’t technical. Its problem is that it requires putting a gun to the head of the Big 4 and blowing their brains out, just to give the keys to the kingdom to SpaceX. That’s simply not going to happen.

    Furthermore, if you gave the keys to the kingdom to SpaceX, they’d soon be a nasty and inefficient as the Big 4 are. There’s really a very large advantage to divvying this stuff up amongst the various players, because they will compete viciously with each other. The competition isn’t so much for the NASA chunks of the architecture, but for the huge land-rush that will occur once the NASA infrastructure is in place enough to facilitate all the commercial guys coming in to exploit it.

    Reply
  16. Find an economical reason to go to the moon. Send a high resolution ore prospector to map the lunar surface from a very low orbit. Then send a few rover to validated its findings. Finding high concentrations of platinum metal ore should be enough economical incentive.

    Reply
  17. 1. Propellant depots orbiting at LEO and NRHO can be continuously supplied with propellant or water, for the production of propellant, from commercial launches from Earth from both large and small vehicles. Any commercial launch vehicle that was capable of deploying a satellite to geosynchronous orbit could easily deploy water or propellant to an NRHO depot.

    2. Reusable LOX/LH2 spacecraft such as Lockheed Martin’s notional reusable lunar crew lander or the ULA’s reusable ACES derived lunar landers could transport crews from NRHO to the lunar surface in just 12 hours. And such vehicles would be able to return to an NRHO outpost within 12 hours.

    3. Such reusable vehicles could also transport crews from LEO to NRHO and from NRHO and back. So only the simplest commercial launch vehicles would be required to transport crews to LEO ( the Falcon 9, Vulcan, and New Glenn) in order to to reach the the lunar surface.

    4. For interplanetary travel, an NRHO departure shaves off about 2.7 km/s of delta v requirement relative to LEO departures.

    5. LEO departures for interplanetary space travel not only requires the supply of propellant from the Earth’s deep gravity well but also a substantial tonnage of water for drinking, food preparation, hygiene, air production, and radiation shielding requiring a delta-v of at least 9.3 km/s.
    6. NRHO departures for interplanetary space would only require the supply of propellant and water from the Moon’s gravity well, requiring a delta-v of only about 2.52 km/s. Water and propellant requirements for interplanetary journeys would be substantially more massive than the dry weight of the vehicle— especially when departing from LEO.

    7. NRHO is probably a good place to test simple rotating artificial gravity habitats needed to safely transport humans on interplanetary journeys that will probably take at least several months to a few years to complete. The station keeping requirement at NRHO are similar to those at LEO and short duration test flights to Sun Earth Lagrange points should be relatively easy to conduct from there.

    The only problem with a NRHO gateway, IMO, will be the temptation by NASA to make the habitat a lot more expensive and complex than it should be. The NRHO gateway simply needs to be a radiation shielded docking port for reusable vehicles traveling between the lunar surface and NRHO and traveling between LEO and NRHO. If its derived from the SLS propellant tank architecture, it would be easy to appropriately shield such a gateway from the heavy nuclei component of cosmic radiation and from major solar events with just twenty to thirty centimeters of water.

    Reply
  18. It’s a great location for a refilling station, but you want to build that station *after* you have access to (comparatively) cheap mass from the Moon for shielding. The Moon comes first. Otherwise the complaint about unnecessary radiation exposure is valid.

    And LEO, within the Earth’s magnetic protection, is the place to do the initial rotating habitat work. No need to deal with the radiation issue at the same time, and we want that work done before we build the lunar orbital.

    Reply
  19. A Lunar Orbital Gateway is also a good spot for testing, especially components and systems that will need to support life in the path of cosmic rays/solar particle events for months/years with minimal maintenance.

    Reply
  20. Surely a Luna:Earth internet relay does not need permanent staff. And we could do zero-G and centripetally induced gravity work/experiments in Earth LEO far cheaper and maybe using the ISS for crew habitat.Does a fuel depot need to have a human crew? Maybe, for maintenance, especially if it is producing the fuel. It ought to make sense to launch lunar water ice to a fuel production station in orbit – simpler than transporting cryogenic liquids, and I believe water ice is denser than the average density of LOX and LH2 fuel. Water can be stored at the depot more easily then cryo-liquids, with fuel produced ‘just in time’.And if you have to make Methane for a BFR ship, you don’t want to ship the carbon to the lunar surface just to haul it back up as fuel. Make just enough fuel on the moon to re-launch the ship to the fuel depot.

    Reply
  21. to get a different perspective on the stars and planets”I interpreted this as meaning having space telescopes set up in Earth and Lunar orbit to get a decent sized baseline in operation.After the concept of a large baseline for telescopes is passed through 3 layers of PR editing before reaching the press release it comes out sounding rather trite.

    Reply
  22. I guess the Trump administration lunar base will happen soon after they have completed the wall and they have forced Iran to give up their nuclear program. He he..

    Reply
  23. To me this seems like a “tough cupcake” article. The authors voices are casting a “NASA is nuts, bone headed and dumb” attitude. Myself, I think that having a really awesome bivouac waystation somewhere between Earth and The Planets is an awesome idea. Not for dumb things like “to get a different perspective on the stars and planets” (what tripe!), or equally foetid from a technical perspective: “to test out engines in different gravitational environments” (paraphrased, both) … that’s just dumb. Mathematically, interplanetary pinball is almost boringly elementary. Seriously… it is. I didn’t say that it was simple. This it is not. But the underlying formulæ that model the real-time motions of bodies in an N-body gravitational environment are WELL worked out. Everything — velocity, momentum, kinetic energy, 1/r² gravitational influence, conservation of momentum as well as surprisingly accurate confinement of energy. It is ALL well worked out. So well in fact, that if one of these purported farther-from-Earth studies were to show even 25 parts per million deviation from what present day double-precision CODE predicts, that’d be a reason to rewrite some parts of Physics. No, those are bad reasons. MUCH better reasons actually exist, but they aren’t palatable (or palpable) by the public generally. Its hard to arrange a sell-job on needing a significant station rotating around the Moon at say +500 km. In fact, it might be interesting to determine what an optimal cis-:Lunar orbit. WHY would it be a decent technological site for an international stronghold?Triple obvious… • (1) a GREAT fuel depot location. • (2) an AWESOME relay for a Luna:Earth internet relay.• (3) An awfully convenient spot to do both gravity-less and centripetally induced gravity work.The idea of having a waystation at each noteworthy (and of-interest) planetary body like Mars, the Moon, Jupiter, Io, or Ceres … is that one can ‘jet’ across the void using up a fairly minimal amount of fuel-oxidizer, then change vehicles to a kind and format which is much better suited to actually landing (or doing other scientific work) on the target orb in question. Likewise, if — in the case of Luna — there is a competitive international effort to manufacture rocket fuels, well … what better than to cryogenically store them on a perilunar space station? Do the splitting, liquifying, chilling and heavy lifting (from Luna to space station) asynchronously from all the operations and needs. The incoming and outgoing spacecraft in turn don’t have to have near the reaction mass to get “there” AND “back”. Just there. Then refuel. Then back. The refuel. Repeat… While that’s about as sexy as envisioning an interplanetary network of British Petroleum filling stations, for something that quite realistically will cost 1 plus 11 zeroes … well … that is for politicians to do.Just saying,GoatGuy

    Reply
  24. I’m happy finally someone pointing out that an lunar orbiting station will be a waste of money and “time”. I always thought that a lunar base should be right way for all reasons stated in this article.

    Reply
  25. It is theoretically possible that multitudes of locations on the Moon could be visited by launching scores of missions directly from Earth, the cost of doing this would be astronomical. “Well yes. By definition.

    Reply
  26. Surely a Luna:Earth internet relay does not need permanent staff. And we could do zero-G and centripetally induced gravity work/experiments in Earth LEO far cheaper and maybe using the ISS for crew habitat.

    Does a fuel depot need to have a human crew? Maybe, for maintenance, especially if it is producing the fuel. It ought to make sense to launch lunar water ice to a fuel production station in orbit – simpler than transporting cryogenic liquids, and I believe water ice is denser than the average density of LOX and LH2 fuel. Water can be stored at the depot more easily then cryo-liquids, with fuel produced ‘just in time’.

    And if you have to make Methane for a BFR ship, you don’t want to ship the carbon to the lunar surface just to haul it back up as fuel. Make just enough fuel on the moon to re-launch the ship to the fuel depot.

    Reply
  27. “to get a different perspective on the stars and planets”

    I interpreted this as meaning having space telescopes set up in Earth and Lunar orbit to get a decent sized baseline in operation.

    After the concept of a large baseline for telescopes is passed through 3 layers of PR editing before reaching the press release it comes out sounding rather trite.

    Reply
  28. Seriously, you’re going to have to get better about quotation marks and attribution, or one of these days you’re going to lose a lawsuit over plagiarism.

    Reply
  29. To me this seems like a “tough cupcake” article. The authors voices are casting a “NASA is nuts, bone headed and dumb” attitude.

    Myself, I think that having a really awesome bivouac waystation somewhere between Earth and The Planets is an awesome idea. Not for dumb things like “to get a different perspective on the stars and planets” (what tripe!), or equally foetid from a technical perspective: “to test out engines in different gravitational environments” (paraphrased, both) … that’s just dumb.

    Mathematically, interplanetary pinball is almost boringly elementary.
    Seriously… it is.

    I didn’t say that it was simple.
    This it is not.

    But the underlying formulæ that model the real-time motions of bodies in an N-body gravitational environment are WELL worked out. Everything — velocity, momentum, kinetic energy, 1/r² gravitational influence, conservation of momentum as well as surprisingly accurate confinement of energy. It is ALL well worked out. So well in fact, that if one of these purported farther-from-Earth studies were to show even 25 parts per million deviation from what present day double-precision CODE predicts, that’d be a reason to rewrite some parts of Physics.

    No, those are bad reasons.

    MUCH better reasons actually exist, but they aren’t palatable (or palpable) by the public generally. Its hard to arrange a sell-job on needing a significant station rotating around the Moon at say +500 km. In fact, it might be interesting to determine what an optimal cis-:Lunar orbit.

    WHY would it be a decent technological site for an international stronghold?

    Triple obvious…

    • (1) a GREAT fuel depot location.
    • (2) an AWESOME relay for a Luna:Earth internet relay.
    • (3) An awfully convenient spot to do both gravity-less and centripetally induced gravity work.

    The idea of having a waystation at each noteworthy (and of-interest) planetary body like Mars, the Moon, Jupiter, Io, or Ceres … is that one can ‘jet’ across the void using up a fairly minimal amount of fuel-oxidizer, then change vehicles to a kind and format which is much better suited to actually landing (or doing other scientific work) on the target orb in question.

    Likewise, if — in the case of Luna — there is a competitive international effort to manufacture rocket fuels, well … what better than to cryogenically store them on a perilunar space station? Do the splitting, liquifying, chilling and heavy lifting (from Luna to space station) asynchronously from all the operations and needs.

    The incoming and outgoing spacecraft in turn don’t have to have near the reaction mass to get “there” AND “back”. Just there. Then refuel. Then back. The refuel. Repeat…

    While that’s about as sexy as envisioning an interplanetary network of British Petroleum filling stations, for something that quite realistically will cost 1 plus 11 zeroes … well … that is for politicians to do.

    Just saying,
    GoatGuy

    Reply
  30. “It is theoretically possible that multitudes of locations on the Moon could be visited by launching scores of missions directly from Earth, the cost of doing this would be astronomical. ”

    Well yes. By definition.

    Reply

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