Lunar Surface Rendezvous and Light Scout Outpost Missions

Lunar Surface Rendezvous
One of the ideas I liked from the TeamVision paper (though I think it could and should be taken farther) was Lunar Surface Rendezvous. Now, this term has been used in several different ways, so I’ll define it as a mission architecture where multiple mission elements are landed separately at the same location, instead of all at once. Lunar Surface Rendezvous (LSR) came up several times during the Apollo program, first as a direct competitor to LOR, EOR, and Direct Ascent, and later as a way of enhancing the existing Apollo architecture. One of the ways that Apollo was originally going to be extended (had funding not been cut due to how unaffordable the transportation was) was to use LSR to preland some extra cargo before a manned landing, thus giving the astronauts a lot more tools, a spare rover, additional life support spares and supplies, and other various odds and ends. This would’ve allowed a lot more to be done in a given mission.

TeamVision suggested a form of LSR using prelanded robotic lunar rovers that would work in conjunction with a 2-man landing team to more thoroughly investigate the area of interest. Basically, the robotic rovers would scout out the area in advance, help the astronauts find the areas of most interest, and generally greatly enhance the capabilities of just the astronauts alone. One of the guys who was involved with the Bay Area Moon Society (David Bushman I think?) had given us a presentation about some of the work he was doing with human/robotic exploration teams, and he made a pretty solid case that humans and robots can accomplish a lot more working together than just humans or just robots could.

ESAS plans to use LSR for its base-buildup and operations missions. Basically, once they’re past the sortie phase of exploration (and with the cost of their architecture, that will probably be a very short phase indeed), and have found a base site, the base will be built up over multiple launches. Some landers will bring habitat equipment, others construction equipment, or ISRU stuff, or crews, or what have you. Even the most dyed-in-the-wool HLV fan has to admit that there’s just no way you could launch a complete lunar outpost in one piece. But once you’re down on the surface, deploying stuff, hooking things up, loading and unloading, fitting out hab modules, and all that other stuff becomes a lot easier. Especially if a lot of the work can be done inside. Being on a planetary surface, under the influence of some gravity makes a lot of those construction tasks a lot more similar to terrestrial operations than trying to do similar tasks in zero-g.

But taking the idea further has some merit too. Doug Stanley, in one of his replies on the Q&A thread previously mentioned, explained that the “4 people for 7 days” requirement came mostly from some NASA studies that had been done pre-ESAS on lunar surface operations. As I pointed out in my previous post on 2-man architectures, there’s no reason that all 4 of those people (and all the facilities to support them for 7 days) have to be landed on the same lander.

Why doesn’t NASA land enough stuff to support 4 people for 6 months on a single lander? Or 6 people for a year? Because it would require much too big of a lander, which would cost too much to develop, and way too much to operate. By making the lander smaller, and less capable, but using LSR, ESAS provides a much cheaper approach than trying to do a Battlestar Gallactica scale lunar lander. However, you could see where that logic goes…

And Doug Stanley more or less admitted it. He said that had the 4 people for 7 days edict not been “blessed” by Mike Griffin as one of the ground rules, that EELV based architectures would have traded a lot better compared to the chosen ESAS architecture. And he’s right. All the numbers I’ve run show that you could probably do a reasonable 2-man lunar architecture using stock, or nearly stock EELVs (or EELV equivalents like Falcon IX if it becomes available).

Light Scout Outpost Missions
The numbers I found show that a lander capable of shuttling a two-person capsule from LUNO to the surface and back is also capable of landing (one-way) a fully loaded Sundancer module. By changing the loadout of the Sundancer a bit (and removing non-lunar useful stuff like ACS systems and propulsion systems, etc), and reorienting it towards a two-person setup, you could probably stock enough supplies and equipment to allow those two explorers to stay around for 14 days, or even possibly overnight if you have the right equipment. In other words, you could probably increase the amount of man-days on the lunar surface, while giving yourself more flexibility.

You could call these missions “Light Scout Outpost Missions” (LSO missions?), because they could still be temporary, would cost a lot less than a full-blown 4-man lander, but would still allow enough time to thoroughly explore the nearby environs without having to commit all the money and resources needed to setup a full-scale base. It would be possible to do a lot more of these, even during base build-up, which would allow for a much more thorough exploration of the moon.

Right now with the existing architecture, there’ll likely only be enough money to try checking out 2-3 locales before you have to settle down into a large-scale base. But with LSO missions, you could probably afford not only to scout out more places before setting down too much infrastructure, but you could also afford to continue such LSO sorties during base buildup, and even better, each LSO mission provides some of the seed infrastructure for future bases if economically interesting resources are discovered (like say if Reiner Gamma turns out to have a nickel iron meteorite core left at the bottom of it, or if an area that had Lunar Transient Phenomena turns out to have subselenian gas pockets, or any of a number of other potentially itneresting features that we just don’t know about yet).

And if a sortie site turns out to be very interesting, its easy to incrementally resupply and send crew rotations there to continue exploration. Or you could use the longer time on the surface to do early precursor work on debugging ISRU processes or testing out construction equipment or processes before you commit to larger scale equipment.

The more you look at it, the more you realize that Lunar Surface Rendezvous is not only the way you eventually have to go for serious lunar development and exploration, but that if taken to its logical conclusion, it ends up also being cheaper, more capable, and more flexible than the alternatives.

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Jonathan Goff

Jonathan Goff

President/CEO at Altius Space Machines
Jonathan Goff is a space technologist, inventor, and serial space entrepreneur who created the Selenian Boondocks blog. Jon was a co-founder of Masten Space Systems, and is the founder and CEO of Altius Space Machines, a space robotics startup in Broomfield, CO. His family includes his wife, Tiffany, and five boys: Jarom (deceased), Jonathan, James, Peter, and Andrew. Jon has a BS in Manufacturing Engineering (1999) and an MS in Mechanical Engineering (2007) from Brigham Young University, and served an LDS proselytizing mission in Olongapo, Philippines from 2000-2002.
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11 Responses to Lunar Surface Rendezvous and Light Scout Outpost Missions

  1. Anonymous says:

    I would guess that the appeal of these can be increased (and the cost lowered) if you go with the ‘Lunar Hostel’ idea that someone over at the Moon Society came up with. Basically, cram a pressurized rover with all your communications and life-support equipment; then have it attach to Big Dumb Volume (BDV) modules which are buried under the regolith. The BDVs don’t have much other than strong airtight walls; but they provide workshop and living space while the rover is docked there.

    Not having much inside (inflatable chairs and tables?), they’re very lightweight, and you can drop them all over the lunar surface comparatively cheaply. Maybe drag them to a suitable site with robots, inflate, then cover with regolith.

    Explorers in their pressurized rover come along, use the ‘hostel’ for a while (possibly as a stopover or storm shelter on their way to another site), then move on, taking most of their gear with them, thus maximizing its utility.

    If desired, they’re easy to convert into a more permanent base; and if they’re abandoned, a comparatively small amount of money is lost, and they may be useful again in the future.

    –Carl.

  2. Robert says:

    Why not use a spacecraft powered by oxygen and aluminum, while the ISP might be lower than a hydrogen oxygen spacecraft.

    First build a spacestation in L1, then you use an inflatable spacecraft to travel from LEO to L1. The spacecraft should have an inner wall and an outer, in between the inner wall and outer you fill that area with dirt and rocks from the Moon.

  3. brian d says:

    Along the same line here’s another way to support LSR

    A Solar Electric Propulsion Cargo Vehicle to Support NASA Lunar Exploration Program
    IEPC-2005-320
    Mission analysis is presented showing the significant advantages of using solar electric propulsion to haul non-time critical mass from low-earth orbit (LEO) to the lunar surface. Results show that a high power SEP system is capable of delivering over twice the mass to the lunar surface when compared to a chemical system and since the SEP system can be reused for multiple missions, the economic advantages over a pure chemical system are substantial.

    Surface cargo delivery ~20,000kg

  4. Anonymous says:

    You’re only one person. NASA has far more information resources than you do, plus they have far more people than you do. So what makes you right and them wrong? How do we know that there are not a hundred other factors that NASA has taken into account that have driven them to their conclusion? For instance, what if they have determined that a two-man crew on a single vehicle is too small due to safety, maintenance, or other reasons? You are assuming that the 4-person requirement was for the most part arbitrary, but you don’t know that.

    Why not publish your calculations here? After all, right now you are asking us to take your word for it that you have come to these conclusions. But only if you put your figures out there can people check them and conclude that you are indeed correct.

  5. Anonymous says:

    Jon

    I actually vastly prefer a four man crew simply because you can get more work done.

    When you design a lander for a two man vs a four man mission the DDT&E really is not that much different so everything is tied up in the launch vehicle costs. There are several variants out there that can be used for launch, including MAX, Direct, or even Ares V.

    The real issue is what are we going to do when we get to the moon. For that we need people as well as advanced telepresence operations. If we have four people there is a good chance that in the future one of them can be a commercial person.

    If you have a SEP stage delivering cargo you still want four people. Two people simply is not enough
    to do useful work on the surface.

    Dennis

  6. Big D says:

    Personally, I think non-LEO rendevous–whether L1 or LSR–is more of a savings than splitting the crew. By using a “slow boat to China” for the base, and a “normal” capsule for the crew, you leverage the same efficiencies that make a Bigelow hab and EELV/F9 more useful for the money than flying a shuttle for two-week science missions once a year (per shuttle).

    Heck, the current wave of Mars plans pretty much all rely on MSR. Why not do the same for the moon?

  7. kert says:

    Any longer exploration plan will inevitably have to be a “surface rendevouz” in one form or another. In case of current ESAS plan, they call for it for base buildup.
    But, if you are going to do it anyway, why not use it from the get-go to reduce initial mission costs ?

  8. tankmodeler says:

    >>How do we know that there are not a hundred other factors that NASA has taken into account that have driven them to their conclusion?

    There certainly are other factors that NASA has taken into account. Unfortunately a lot of them are biased towards keeping the marching army fully employed and are not, necessarily, driven by any real science. Several parts of the ESAS were imposed, as Stanley discussed. That being said, if the clean sheet of paper were entirely clean, other options do become more viable.

    >>For instance, what if they have determined that a two-man crew on a single vehicle is too small due to safety, maintenance, or other reasons?
    Two men seemed perfectly OK for Apollo.

    If you decide that 4 is a better crew size to work ont he moon for a number of weeks, then you can send a second 2-man crew up. You also have the option of lunar base resupply, which you don’t have in the take everything-at-once nor do you have the option of extending missions past the lift capacity of the everything-at-once lander. With LSR you just send more supplies.

  9. Anonymous says:

    As Jon has said in several different places, the primary goal of this architecture is to use, to the maximum extent possible, existing hardware, thus enabling manned missions to the moon in just a few years from now. Obviously, he is working from requirements that differ greatly from the requirements that NASA is working from.

    Although these plans are based primarily on back-of-the-envelope calculations, they still show there are a great many possibilities for performing manned lunar missions than have been considered by NASA. Jon may be doing these calculations to satisfy his own curiosity, but I appreciate the fact that he is willing to share them with the rest of us.

    In the end, even if NASA does not end up using anything even remotely resembling this architecture, it is still of use to know that it is within the realm of possibility. And who knows, perhaps SpaceX or Lockheed-Martin will take a similar approach and find a way to make commercial lunar missions a practical reality.

    Keep up the good posts, Jon.

    Ad astra per aspera

  10. Anonymous says:

    “Although these plans are based primarily on back-of-the-envelope calculations, they still show there are a great many possibilities for performing manned lunar missions than have been considered by NASA. Jon may be doing these calculations to satisfy his own curiosity, but I appreciate the fact that he is willing to share them with the rest of us.”

    But he _hasn’t_ really shared his calculations. He has simply made assertions that he is right and NASA is wrong, without providing sufficient details for us to determine that he is correct.

    History is filled with proposals that looked great to one or two people, but that fell apart once a team of experts were involved to make them real. There’s no guarantee that Jon didn’t forget to dot an i or carry a zero. So far, what we have is him asserting that he’s right, and a large organization, with access to much greater resources and data, saying that he’s wrong.

  11. Jon Goff says:

    Anonymous,
    But he _hasn’t_ really shared his calculations. He has simply made assertions that he is right and NASA is wrong, without providing sufficient details for us to determine that he is correct.

    What do mean “hasn’t shared his calculations”? Did you read my latest post where I provided a link to the spreadsheet (and a list of the assumptions that went into the spreadsheet)? And the following discussion and addenda? Sure, I didn’t make CAD models, FEA and Bills of Material for the design, but I’m not exactly getting paid to do this either. I’ve been perfectly willing to put ideas and numbers and calculations out there for others to look at and debate.

    History is filled with proposals that looked great to one or two people, but that fell apart once a team of experts were involved to make them real. There’s no guarantee that Jon didn’t forget to dot an i or carry a zero. So far, what we have is him asserting that he’s right, and a large organization, with access to much greater resources and data, saying that he’s wrong.

    The history of that organization is also full of large groups of smart people making dumb mistakes. It happens. Just assuming that because one person supports something and a lot of people support something else that the larger group is right is, well kind of silly. In spite of being a large group of smart people, NASA has still managed to kill over a dozen astronauts, build a lunar architecture once that was so expensive it couldn’t be sustained, and generally blow billions of dollars on technical systems that have been admittedly fundamentally flawed from the outset.

    I’ve published some numbers. If you have a beef with them, or think I’ve made mistakes, point them out. Arguments by authority don’t hold much water with me.

    ~Jon

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