Campaign '08, NASA

More criticism, more studies

Yet another critic of NASA’s exploration architecture has emerged: Apollo 11 astronaut Buzz Aldrin. The Orlando Sentinel reports today that Aldrin wants to convene a “panel of experts” to study whether Constellation is the right approach to implementing the Vision for Space Exploration. “We need to stick with the mission but rethink some of the ways we implement it,” he told the paper. “It doesn’t pay to stick with a bad idea.”

Aldrin has won over some prominent individuals and organizations, including former senator Jake Garn and the Center for Strategic and International Studies. Aldrin may also have the ear of the campaign of Democratic presidential candidate Barack Obama: a campaign spokesman told the Sentinel that there have been discussions between the campaign and the former astronaut, and that “we are expecting a more detailed proposal from him soon”.

This is not the only effort that is reexamining either the Vision or its implementation. The article also notes that National Academy of Sciences is putting together its own panel to study “the goals and rationale” of the space program. In addition, The Planetary Society is apparently drafting its own recommendations, including the possibility of bypassing a human return to the Moon in favor of exploration of near Earth asteroids.

It would seem that, while the major presidential candidates may be vague about the directions they would pursue in space policy, the winner will have no shortage of suggestions.

30 comments to More criticism, more studies

  • Wasn’t it the Planetary Society that sponsored the current plan? While I am not a particular fan of Dr. Griffin’s approach, we do have to pick some approach and stick to it, and I find myself dismayed on several levels that the Planetary Society has changed their tune and now want another approach. That said, I do think that a set of asteroid missions (if they are planned in such a way to lead to a future of exploration and eventually resource extraction) could be just as scientifically and (eventually) industrially valuable as a lunar base.

    — Donald

  • A mission to an asteroid would be useful as a precursor to sending a crew to Mars because it would give us the ability to test and prove our long distance flight hardware and systems before committing to Mars. If something goes wrong, it is easier to abort and get back home than it would be once committed to a destination like Mars; not “easy”, but “easier”.

    Having said that, I don’t think an asteroid mission INSTEAD of going to the moon is a good idea, provided that the lunar missions are in accordance with the original goal, which was to use the moon as a test bed and a stepping stone to Mars. An asteroid mission would let us test and prove our flight hardware, but we need to also test and prove our surface hardware, and that’s where the moon comes in. We still need to go to the moon.

    To sum up, I think an asteroid mission would be good to be used in conjunction with lunar surface operations, both before going to Mars. Neither one should be THE goal, but both should be viewed, and used, as stepping stones along the way.

  • Craig Ballew

    I can think of two reasons that the Planetary Society might be considering changing their tune. First, due to the fact that the current design of the Ares launch vehicles has deviated from the original proposals that reused existing shuttle components to the point of where they should be considered as completelely new designs. Next is the fact that the anticipated yearly costs of the Ares program are going to eat up so much of NASA’s budget which will leave much less available for the types of unmanned science missions that the Planetary Society wants NASA to perform.

  • spector

    Whilst I usually don’t like the constant changing of plans with NASA, I do think a change to asteroids makes sense. Especially as it could also be a chance to develop hardware/experience for a Phobos/Deimos precursor mission.

    From a funding perspective, not developing Altair and avoiding the very expensive (in development and life cycle costs) lunar base may be the only way to save the VSE politically. The Orion, plus heavy-lifter and asteroid/Phobos-Deimos experience might just get us to Mars sooner.

  • sad to see the mythical Buzz Aldrin help the Direct-lobby of losers

  • Chuck, I agree, and would expand one point. Much of the technology required to return to the moon would be more-or-less directly applicable to an asteroid mission, but not necessarily the reverse. If I am correct, than it would make more sense to go back to the moon, then adapt the infrastruction to asteroid (and PhD) missions.

    — Donald

  • sc220

    If I am correct, than it would make more sense to go back to the moon, then adapt the infrastruction to asteroid (and PhD) missions.

    Actually it would be much less in terms of both energy and systems development. Lunar or Mars surface missions require considerable development of landers and support systems that one would not require for PhD or asteroid missions. However, the interplanetary spacecraft/habitat/laboratory would still be relevant.

  • anonymous

    The Ares architecture is deeply flawed, and is already showing the
    strains years ahead of any hardware construction.

    The program was started with zero margin and with ridiculous goals
    of retaining the entire workforce.

    Had NASA used the assets of teh EELV and the ISS, they could make it
    work, but that they poured billions into this mess of a project

  • Al Fansome

    DONALD: If I am correct, than it would make more sense to go back to the moon, then adapt the infrastruction to asteroid (and PhD) missions.


    If it “would make more sense”, this suggests you could make a clear & compelling argument for focusing on the Moon before the asteroids.

    I can make a clear & compelling case for the opposite — focusing first on asteroids. Such a focus would be much more “sustainable” and “affordable”. Let me make a summary case for focusing first on the asteroids.

    1) Sending humans to asteroids, and using them, is a lot easier than establishing a lunar base, and using the materials on the Moon for the benefit of people on Earth..

    Because the cost is substantially lower, it increases the chance of success, and shrinks the schedule between now and success (increasing political sustainability).

    2) It focuses NASA, and the nation, on a mission that is undeniably important (and therefore politically sustainable).

    The benefits of a focus on asteroids are obvious, compelling and easy to explain to the average American (as opposed to the current program, which NASA has never figured out how to sell.) It is called Planetary Defense, and it is obvious to the average Joe and Jane that our nation should be doing something about this. This means it is easier to sell the mission. (It is also more inspirational.)

    A lot of posters here like to complain that the politicians don’t support funding for NASA. Guess what!? This program will sell a lot better than the current program.

    3) Part of the NASA mission could be to capture & return a *small* platinum-group metal (PGM) asteroid to Earth orbit, or part of a small PGM asteroid. Perhaps to one of the Lagrange points. The U.S. Government would then license U.S. companies to mine the asteroid for commercial utilization. (This would directly addressing the economic benefit argument, which would further increase public support).

    By small, I mean less than 50 meters, perhaps as small as 25 meters. Keeping it small has several benefits — it is easier to move and control. It is also much safer. (You keep it small enough so that it would safely burn up in the atmosphere if you lost control.)

    Such a focus would also require a telescopic survey mission to discover asteroids down to this size, and to assess their type. This search is totally within our capability. In fact, Mike Griffin has testified to Congress on how to do this (before he became NASA Administrator.)
    The Testimony of Dr. Michael Griffin, Head of the Space Department, John Hopkins University Applied Physics Lab

    Mister Chairman and members of the subcommittee, thank you for giving me this opportunity to comment on the greatest natural threat to the long-term survivability of mankind, an asteroid impact with the Earth.

    An infrared telescope in, or near, the Venus orbit, looking outward is all that we need. Imagine what we might find if we built a second copy of the James Webb Space Telescope, and placed it in that orbit.


    – Al

    “Politics is not rocket science, which is why rocket scientists do not understand politics.”

  • Charles In Houston

    The reply that addressed the intent of the original post, and was technically correct as well, was “anonymous” when he said:

    The Ares architecture is deeply flawed, and is already showing the
    strains years ahead of any hardware construction.

    The program was started with zero margin and with ridiculous goals
    of retaining the entire workforce.

    The Ares project appears to have been started as an attempt to recreate the glories of Apollo and now they are designing as they go along.

    The program appears to have been designed assuming a steep increase in funding, with a 65 percent chance of making it’s milestones assuming that increase in funding. Reality was that the funding would, at best, stay level. And by designing to a 65 percent chance of making milestones – aren’t most big programs designed with an 85 percent chance, I gotta go back and find my original reference – we accepted much greater than normal slips.

    So we are committing ourselves to a program that cannot succeed as designed and we will have to continue designing and trying to justify funding at the same time – getting money for a shifting, slipping design.

    With that as the reality of our situation this is certainly a good time to step back and look at our situation and see what alternatives we have.

    Then see who is elected and what they want to do.

    Fasten your seat belts, put your tray tables in the upright and locked position. The next couple of years will provide a rough landing for someone.

    The idea of going to asteroids, the Moon, etc is wonderful but will we (any country on Earth) have any vehicle available that can get there? We might only have Soyuz, and I would not think that anyone wants to ride a Soyuz anywhere except to the Space Station.

  • Bob Mahoney

    ‘Round and ’round
    The debate still festers,
    Amid an ever-expanding
    Cavalcade of jesters.

    Where will it end,
    Does anybody know?
    Around the next bend,
    Perhaps nobody will go.

    All this talk about switching destinations (e.g., asteroids vs the Moon) ignores the original underlying premise of the VSE, which was to give NASA (and the nation) a guiding, forward-looking purpose that could justify the pursuit of something as expensive & risky as human spaceflight. Inherent in the formulation of this goal was a desire to avoid the programmatic ‘mistakes’ of the past (e.g., the self-limiting one-shot flags & footprints objective of Apollo, the seemingly aimless cornucopia of low-earth orbit utility that was shuttle & ISS).

    That purpose wasn’t to pick a particular place to go or even necessarily to develop this or that specific rocket or spacecraft. It was to develop a sustainable, affordable space operations architecture that would eventually enable extended, long-term solar system exploration and exploitation. In other words, the point of the VSE was to lay the groundwork for opening up ALL possible destinations.

    The Moon was originally chosen as destination #1 because it holds strong potential as a nearby training & development ground. Mastering long-term, comprehensive lunar exploration (itself a significant set of serious challenges promising significant science return) offers the opportunity to flatten out the learning curves on multiple “exploration-necessary” technologies & procedures within a few days’ travel and near-real-time communications range of Earth. The Moon also holds the possibility of serving as a resources reservoir that may ultimately lessen how much material must be lifted out of Earth’s deep gravity well to support longer-range travels. That we already possess significant knowledge and some on-site experience with the Moon obviously serves as a strong foundation that will increase safety margins while we expand our exploration operating envelope “within sight of home.” No other single destination in space offers all these near-term advantages.

    The most important questions regarding Constellation’s current designs shouldn’t focus on whether or not we’re going to the Moon; that was always a logical part of the long-term strategy. More critical is whether or not those designs, by being focused so tightly on subsequently defined lunar (or Congressionally mandated) constraints, are potentially excluding eventual trips to other destinations. By focusing on the nuts & bolts of getting boots back on the Moon, is NASA losing sight of the longer-term capabilities that Project Constellation is supposed to enable? The Crew Exploration Vehicle was very intentionally tagged with a generic name, not a lunar-specific one.

    That some here are suggesting that this or that destination offers better ‘sales potential’ to the public only highlights how badly NASA’s own public relations efforts have been, and brings into question whether or not NASA itself has lost sight of the proper context of our return to the Moon. Lunar return was always and should remain a fundamental steppingstone that will enable trips to those further locations and should never be portrayed as anything less. ALL those destinations, and potential activities, should be part of the comprehensive ‘sales pitch.’ Otherwise Project Constellation really will become (if it even gets that far) nothing more than “Apollo on Steroids.”

    Scientifically and engineering-wise, it makes sense to restart our exploration of the greater solar system on the Moon, both for what we will learn there about how to explore and for its resource potential. If only NASA could get this bigger picture across to the public (and assuming their designs reflect this strategy), perhaps they would have a little less debate on their hands.

  • me

    ford aka gm aka gaetanomarano,

    “sad to see the mythical Buzz Aldrin help the Direct-lobby of losers”

    It just chaps your ass that Direct is getting publicity. Why don’t you stop your senseless and obnoxious comments so that the good readers of this forum don’t have to read past them to ignore them. The only benefit of you continuing to post here would be that it would lead to you being banned from yet another forum.

    With regard to your comment, you are wrong on many counts.
    1. Buzz is real, he is not mythical
    2. It is sad to only you since you are jealous of Direct
    3. It is a great thing that Buzz is questions the ESAS.
    4. With regard to “mythical”, that is a perfect description of FAST-SLV and your insistence that Direct came from it.

  • Paul F. Dietz

    Recently, the risk premium on federal debt instruments began rising. It is now on the same level as Britain and Japan, and above that of German debt.

    This suggests the US is beginning to approach a boundary beyond which continued federal deficits will become increasingly difficult to finance. In such an environment, struggling programs like NASA’s manned space effort are particularly vulnerable.

  • Dhum Mhurken

    The US is in debt?

    Haven’t heard a word.

    How can that be? Tell US it isn’t so :

    There must be some mistake, you’d think that CNN would be covering it.

  • RayGun

    Nice call me.
    From the Orlando Sentinel comment section.

    gaetano marano
    Cosenza, Italy Reply »
    |Report Abuse |#31 Friday Jul 25
    sad to see the mythical Buzz Aldrin help the Direct-lobby of losers

  • spectator

    Buzz is a very bright guy but this is coulda, shoulda, woulda. Direct X.0 didn’t make it, its not going to happen. If the current incarnation of the vehicles to support VSE are scrapped because Nasa didn’t do its math right, there is little chance that McCain or Obama will want to pour additional billions into Direct on top of what Nasa has already spent on Constellation. The best outcome for everyone is that the pro’s at Nasa did there sums correctly, Constellation comes online within 1 year of 2015 and it delivers the needed tonnage to LEO. Its what we all want right?

  • Its what we all want right?

    No, some of us want affordable access, and sustainability.

  • Norm Hartnett

    Well said, Bob Mahoney, but lets take a closer look at the NASA ESAS response to the VSE.

    It’s obvious that any mission to anywhere other than LEO will require the assembly of a space craft in LEO, mankind as used four architectures for doing such assembly;
    1) FGB, each module is sent to orbit with built in maneuvering, rendezvous and, docking capabilities and assemble themselves.
    2) Progress tug, modules are sent to orbit with an attached tug that performs maneuvering, rendezvous and, docking and then the tug is disposed of.
    3) Apollo, manned capsule provides maneuvering, rendezvous and, docking.
    4) Shuttle, provides maneuvering and rendezvous and assists in docking.

    ESAS selected the Apollo method to address the VSE but that approach is limited to two modules, a manned segment and a second segment with fuel, engines, and Lander. So far as I can tell nothing in the ESAS discusses how multiple modules would be assembled for any missions beyond the moon. Using the Apollo method also means that once a mission is complete the total infrastructure in place would be an expended Lander and some payload on the moon, one used capsule and three SRBs on Earth requiring extensive refurbishment. This doesn’t appear to be a sustainable architecture to me.

    I believe it is well past time to reexamine the ESAS study and an independent group is the preferred method to conduct a new study, in fact I’ve been advocating such a reevaluation since it was discovered that the SSME would not be usable in the Ares I.

  • Space Place

    The SSME is perfectly usable in the Ares I, certainly in a sustainable space program where spacecraft are assembled in orbit and nothing is expended.

    You’ll have to get rid of the first stage, though.

  • Bob Mahoney

    Mr. Hartnett,

    Thanks for the positive comment.

    While I agree with your conclusion, I believe your implied reduction of the trade study (intended or not) to only 4 architectures (see comments on those, below) may set up a fall into the same trap that the ESAS team did: making unnecessarily restrictive assumptions up front that exclude (or at a minimum severely hamper) pursuit of a robust, flexible, and sustainable architecture that will bring multiple destinations into our sphere of operations.

    Regarding your four examples:
    O you neglected to include,
    – from history: Agena/Gemini (crew-involved rendezvous & docking
    with an uncrewed disposable propulsive stage);
    – from numerous design studies: the multiple alternatives made
    available via aerobraking OTVs, in-space assembly/refueling
    depots, Lagrangian Point rendezvous, or space tethers.
    O Progress isn’t launched with the modules it maneuvers.
    O Apollo was cislunar, not LEO, assembly following joint launch on a single booster, followed by crew-involved LOR.
    O Shuttle-assisted includes both teleoperation (RMS work) and EVA-assisted (e.g., Intelsat VI/STS 49).

    Again, I agree with your conclusion, and your highlighting the disposability of the ESAS architecture elements as a serious flaw in its sustainability is a vital observation. But I fear dangerous shoals ahead if we start restricting the design options with arbitrary categorizations that aren’t necessarily warranted, or may be incomplete or inaccurate.

    Warmest regards.

  • Norm Hartnett

    Mr. Mahoney thanks for your response. You are correct I did limit the trade space. I attempted to limit it to what we have actually accomplished

    WRT Agena/Gemini and Apollo I believe they use the same general assembly method in different locations. More or less the same method proposed for Constellation.

    WRT Progress, I was referring specifically to the Progress M service module used in M-SO1 to deliver the Pirs module and that was launched with and used with several modules during MIR assembly.

    I probably made an error when using program/ship names to classify the various assembly architectures used to date.

    Perhaps this would be better.

    1) Modules with integrated maneuver, rendezvous, and docking capabilities.
    2) Modules using tugs with some portion of the maneuver, rendezvous, and docking capabilities disposed of after assembly.
    3) Using a manned ship to assemble modules by stacking.
    4) Using a manned ship with RMS and EVA capability to assemble modules.

    In any case I have difficulty believing that the CEV would be capable of performing assembly of a multi-module Mars transport vehicle. This means that over and above all the issues that the Constellation program faces now they will still have to develop some form of module assembly for Mars and beyond.

  • Norm Hartnett

    Note that when the HTV successfully completes their first mission we will have a new possible assembly technique. Maneuver and rendezvous performed by the module and docking performed by the station.

    Constellation/ESAS architecture is simply not sustainable for much the same reasons that the Apollo architecture was not sustainable.

    I personally advocate that NASA maintain and utilize the current shuttle architecture, developing, if necessary, one or more robust new shuttles based on the current infrastructure. At the same time NASA should invest heavily in CRS and COTS D and expand that to include delivery of modules. NASA’s current CRS method of paying by the Kg. delivered could be an excellent way to motivate development of cost effective LEO access if stringently applied to the procurement criteria and should be carried over to COTS D and follow on programs. Once those assets come online the shuttle should be retired or redesigned as an experimental craft of exploring the RLV envelope. The ISS should be partially repurposed for interplanetary vehicle assembly, maintence, and refueling. And finally the development of a robust, long lifetime reusable vehicle for access to the moon, the asteroids, and Mars should be begun.

    That’s what I would hope an independent review of the current NASA mission/architecture would select. Something sustainable, long term, and that would grow both our commercial capabilities and have space for our international partners.

  • Bob Mahoney

    Mr. Hartnett,

    Your clarifications were helpful but again I view them as too narrowly defined; they speak only of the mechanics of the linking of modules once delivered. This is a significant driver but not the only important one.

    I must admit I had forgotten about the Pirs delivery.

    I disagree that Agena/Gemini, with the propulsion module launched separately from the chaser, is fundamentally the same as Apollo. I consider it very important to include the launch architecture (among many other factors) as part of the overall picture because it is a fundamental driver of feasibility both technically and economically. (Just as important is the location of your rendezvous & docking/link-up.)

    Continuing to fly Shuttle is likely not a viable option, primarily because of its operating cost. $3B+ per year just to get to and from LEO is a crippling expense. [Not that it’s looking like Ares I/V will be any cheaper…] The time to have evolved its design was post-Challenger; another lost opportunity born of shortsightedness. [But I’m still waiting for someone to explain why we can’t develop an ET insulation that doesn’t fall off; SO WHAT if we take a payload hit?]

    This is why I believe the time for your suggestion to pursue a robust, reusable vehicle (or vehicles) for access to the Moon, asteroids, and Mars has come. This was the idea behind the CEV; let’s not confuse the current lunar-centric ESAS/Constellation implementation with the original VSE intent.

    ISS’s current config & orbit make it a very expensive choice for use in interplanetary (or lunar) mission support. Even if we could move it gradually (perhaps with long-term electric ion thrusters and/or an electrodynamic tether) to an inclination closer to the ecliptic, it’s current design is that of an orbiting laboratory, not a vehicle assembly hanger. By the time it might be called on to support such operations, we’re going to be talking about the same lifetime and upgrade issues that are plaguing Shuttle today.

    I heartily concur that development of commercial alternatives to replace the shuttle’s up & down capabilities is vital. If NASA were to get serious about this instead of building its own version to compete, it just might bring about a revolution that could change the entire picture.

    Thanks for your thoughts.

  • […] Space Politics » More criticism, more studies […]

  • Me

    “ISS’s current config & orbit make it a very expensive choice for use in interplanetary (or lunar) mission support”

    Common misconception. It is only a 6% payload hit

    “to an inclination closer to the ecliptic”

    makes it unusable for the Russians. Their vehicles can’t access it

  • makes it unusable for the Russians. Their vehicles can’t access it

    They will when they start launching out of Kourou.

  • Bob Mahoney

    Me: (Is that as in, Windows Me? Ugh. Watch out for those ‘blue screens of death’…)

    ONLY a 6% payload hit? From where to where, exactly?

    If Earth-based, each piece of hardware and each pound of propellant lofted into orbit from KSC will lose some delta V advantage by not launching directly east to 28.5 (which is only 5-degrees above the ecliptic). [And impose the ~5-minute planar constraint to the launch window, but I digress.] THEN all that same hardware, now assembled in the 51.6 degree inclination orbit, would ultimately have to get itself back down to 28.5-18.5 (the range of the Moon’s orbit plane) for lunar operations or 23.5 (i.e., the ecliptic) for interplanetary missions. [This of course assumes you don’t want to constrain your arrivals at your ultimate destination to the 51.6 deg departure plane.]

    If we advance ourselves along to being able to bring material (propellant and/or h/w) from the Moon for incorporation in an interplanetary mission to be assembled at ISS (eventually we hope this level of technological maturity will come to pass even if the utility of doing so doesn’t become apparent), then we have to climb off the 5-deg inclination lunar orbit plane to reach ISS at 51.6, transfer/assemble the parts, and then climb back down into the ecliptic plane at 23.5.

    For any long-term set of operations (meriting nonterrestrial COMSATS, ongoing deliveries of supplies & crew, etc), even if you break up and optimize the planar changes for all these transfers or fold in Libration Point rendezvous options, 6% (assuming this number does account for all the plane changes required or desired), stolen from EVERY payload pound destined for an outbound (or in-bound) trajectory, is going to add up.

    And all this complexity (=operational cost) is just in the realm of the repeating underlying dynamics and consequent propellant consumption concerns. You also must factor in the cost of modifying the ISS to accommodate interplanetary vehicle assembly, checkout, and servicing. By the time we’re ready to develop such a capability, the current ISS hardware will be 20+ years old. How many SARJ-like breakdowns will have occurred by then across the entire structure/vehicle?

    Yes, you CAN accommodate the ISS in a long-term architecture, but I doubt the benefits of doing so will outweigh the cost—both in dollars and operational complexity. For good or ill, this particular die was cast when we shifted from Freedom to ISS in the 90s.

    If we need a LEO assembly base for interplanetary vehicles or lunar base OTV support (a very big if, but the radiation protection afforded by being below the VA belts is but one advantage), I believe it makes more sense to gracefully retire the ISS National Lab in two or so decades, from its current orbit, and put any lessons learned toward a 28.5-degree inclination facility. Unlike JSC in Houston, KSC was put where it was for legitimate technical reasons along with the political and economic ones: its latitude skirts the top of the Moon’s orbit plane and is only 5 degrees away from the ecliptic.

    Regarding the Russians, they will be launching Soyuz vehicles from Guyana (at 4 degrees latitude) soon. If they so desire, they can build launch pads for other vehicles there as well. Imposing such a constraint (a 51.6 degree inclination) on an entire solar system exploration architecture merely to accommodate one partner’s geographic history is just the sort of short-sighted “engineering assumption” that we must avoid.

    We’ve had too many of those imposed already.


  • Al, while I don’t think you analysis of asteroid missions obviates my point that doing the harder task first makes the easier one, well, still easier, I fully agree with your every word. I would add that asteroid exploration gives you early experience in interplanetary deep space, and gives you early experience with the kinds of bodies that dominate the inner Solar System. It also sets you up for Mars via PhD-type missions.

    Charles, the Soyuz was initially designed for flights into lunar space, then adapted to LEO. Further adoption, with suitable upper stages, should recreate that capability. Near earth asteroids may involve slightly higher reentry speeds, and will certainly require better life support and / or supplies, and better radiation protection during long flight times, but I agree with Al that the requirements (with the possible exception of the last one) should be easily within reach.

    Unfortunately, Paul is entirely correct about future budget difficulties, and this all may be academic.

    Bob: I am agnostic on using the ISS itself for assembly — though I think assembly is an essential skill — however, it’s my understanding that vehicles returning from a lunar polar base will reenter over the terrestrial poles. If so, it should be possible to aerobrake into the ISS orbit, which might make it appropriate to support a reusable infrastructure optimized for the lunar poles. Any thoughts?

    — Donald

  • Bob Mahoney


    I didn’t realize we were expressing our religious views here. : )

    One of the original viewgraph selling points of placing the lunar outpost at a pole was “minimum delta V.” I am STILL waiting for someone to explain this, because it runs counter to every ounce of space mission design training I received. I think someone somewhere did some pretty fancy hand-waving to come up with that ‘advantage.’ All I see, coupled to the chosen EOR-LOR architecture, is another layer of lunar-focused constraints that inhibit flexibility and applicability to supporting other destinations, such as the E-M L4/L5 points, asteroids, and Mars. I personally think it’s a little presumptuous to plan on placing a base at a pole before we put anything down there to assess the ground truth.

    As for aerobraking from 85-95 degree inclination lunar-return trajectories down to 51.6, I don’t recall ever seeing specific analyses indicating how many degrees might be accommodated with a given lunar-return trajectory pass. My gut tells me that it would require quite a few dips into the atmosphere to bend a full 45-55 degrees without vaporizing the vehicle. That was one of those things that the Aeroassist Flight Experiment might have taught us (you know, that relatively inexpensive forward-looking project that was cancelled during the 90s to help us afford the “much-less-expensive-now-that-the-Russians-are-onboard” ISS?). I suspect that such a multi-pass operation, necessary for every returning vehicle, would add significant complexity to the logistics train for minimum benefit. I still hold that building a new purpose-built servicing facility (if it is in fact required) at 28.5 makes more sense in terms of enabling trips to ALL possible destinations.

  • Bob Mahoney

    Donald et al:

    I should correct my moment of snide bitterness above. The Russians were not yet part of the space station program when AFE was cancelled in 1991. AFE went away (mothballed & shelved might be a better description) more properly on the tail end of the evaporation of the SEI. The agreement to have Russia come on board was signed during 1993, even as NASA was executing its orders from the White House to downsize Freedom into the less-expensive ‘Alpha’ configuration.


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