The NASA Budget

Eric Berger has looked at it, and (unsurprisingly) the Trump administration seems to be in no hurry to get back to the moon. The NASA budget is going to become increasingly irrelevant in the next few years.

[Update a while later]

Dick Eagleson wonders not only if SLS’s days are numbered, but just how low the number is?

SLS, as currently envisioned, is a farce. Its development has been glacial and insanely expensive. It plows absolutely no significant new technological ground. It will be slow and insanely expensive to build. It is entirely expendable. Its associated spacecraft, Orion, is, at best, a Moon-craft, lacking heat shielding sufficient to withstand an Earth return from any significantly more distant point and, in any case, having life support capability for only 12 person-weeks of continuous occupancy.

But other than that, it’s great.

Last week’s launch was a major temblor, I think.

[Update early afternoon]

Here‘s Christian Davenport’s story (I saw him at the launch last week).

[Tuesday-morning update]

Katherine Mangu-Ward: It’s not a crazy idea to privatize the ISS.

40 thoughts on “The NASA Budget”

  1. The budget to be proposed for NASA later today will offer some preliminary support for a lunar exploration program but has no specific timelines for when humans might return to the surface of the Moon—nor funding to make such an ambitious undertaking happen.

    All governments really need to do is get out of the way.

  2. Some of this NASA budget will be DOA on the Hill, obviously.

    But what will remain essentially intact is the HSF ledgers, save probably for some congressional insistence that NASA work to keep ISS up through 2028. Most of Congress has no more interest than Trump does in lunar exploration, but plenty have an interest in keeping certain workforces intact.

    It’s sad, but not a terribly inaccurate representation of what the American public wants, to the extent that it thinks about space at all.

    1. Some of this NASA budget will be DOA on the Hill, obviously.

      Didn’t look like there was anything too objectionable in the article about it except for a couple small cuts to two departments. And wouldn’t a cut to astrophysics represent winding down some missions that have, or are, ending?

      1. The plan to scuttle ISS in 2025, the Earth science sats, and WFIRST are the obvious objection points.

        I expect that some of the sats will be saved. WFIRST is a harder call. A lot of unhappiness on the Hill with how badly JWST went over budget, fears that WFIRST is turning into the sequel. But WFIRST has a lot of supporters. Perhaps it might end up getting reconfigured.

        1. ISS has survived the past two administrations’ attempts to end it, so maybe it will this time too. The difference this time, is that there could be physical alternatives to look at by the time 2025 rolls around. NASA might even have astronauts on them.

  3. “For example, under a table titled “Lunar Exploration Campaign,” the agency will fund small- to medium-sized landers between now and 2023 (up to 1,000kg to the surface of the Moon), before finally beginning work on a human-rated lander in late 2023 or 2024.”

    Sound good to me.
    I think NASA should start with robotic missions to lunar pole and about 8 year into program start the crew lunar landing part. So, 2018 + 8 is is 2026.
    But need to start depot near beginning and have robotic lunar missions use LOX from the depot in LEO. And eventually crew mission will also use LEO depot. As will Mars exploration program, which should start around 2028. Or only give a couple years for the lunar crewed landing and their lunar sample returns.
    Anyhow, I having heard anything lately about a depot, and it should be about 1 billion dollar program- depending how you do the accounting.
    Or if count all the operational years and it’s refueling it could be a lot more. Or I have no clear idea of how that program would last- depends on how it goes and whether or when it becomes a commercial operation- and then it’s buying fuel and then that’s part of whatever mission budget uses it.

    1. Anyhow I looked and didn’t see anything new, but looking at older paper:

      –“Boiloff Sensitivity
      There is currently no standardized method
      to model cryogenic propellant boiloff while a
      vehicle is in space. Additionally, the choice
      of the propellant boiloff rates in this study
      may seem somewhat arbitrary despite their
      traceability from the ESAS Final Report.”
      “Given the data above, the LH2 boiloff rate is
      widely varied from 0% per day (zero-boiloff
      case) to 1.0% per day. Similarly, the LOX
      boiloff rate is widely varied from 0% per day
      to 0.1% per day. ”

      Table 13 summarizes the total fixed costs
      for both depot options. The PRM cost is the
      DDT&E cost associated with a Delta IV
      Heavy-sized PRM; the aerocapture cost
      represents its associated DDT&E cost. All
      costs are in $M FY2006 USD.

      Aerocapture Propulsive Difference
      Depot $2,092 $4,897 $2,8

      the fairing would have to be lengthened slightly in order to
      contain the depot.
      Depot Diameter 7.8 m
      Depot Length 17.59 m
      Dry Mass 13.6 MT
      LH2 Storage Capacity 11.9 MT
      LOX Storage Capacity 66.3 MT
      O/F Ratio @ Capacity
      Total Wet Mass
      94.0 MT —

      So I say forget about LH2.
      I think depot for LH2 in High Obrit- Ie, Earth/moon L-1,
      might be good. But I think NASA should focus on LEO and
      most of the mass of the rocket fuel- LOX.
      Or I think including LH2 would cost more, and what think is
      important is all operational aspect connected to a depot is
      what is needed.
      Or get a LOX depot working- other stuff can be later.
      I think one can start with small storage capacity.
      LOX has less volume needed, but I mean don’t need 60 tons or more.
      Or again it’s not how much rocket fuel a depot can hold, the focus
      is making it operational.
      Roughly having 60 tons of LOX in depot, is “like” added 60 tons
      that rocket can lift to LEO. Or Making SLS with 70 tons to LEO
      be 70 + 60 = rocket able to lift 130 tons to LEO.
      Now one could argue you need that for Mars, don’t need it for robotic
      lunar missions and not even for crew lunar mission.
      And after getting LOX depot operational. And another depot could be
      put in high orbit [same depot] and it would like adding say 180 tons to
      amount rocket could launch from Earth- or 250 tons to lEO rocket is more than need for Mars. And second depot would be cheaper and probably be better than than first depot- though one might add LH2 and be more expensive.

      1. “So I say forget about LH2.”

        Or maybe… do some engineering test missions to get real data?

        Cheap launch means you can be empirical rather than doing endless analysis.

        1. “Paul D.
          February 13, 2018 at 6:44 AM

          “So I say forget about LH2.”

          Or maybe… do some engineering test missions to get real data?”

          Yes. NASA depot should be considered experimental, just as shuttle program would been better if the shuttle was regarded as experimental.
          Or don’t imagine that this NASA depot going to be cheap way to transfer rocket fuel, we can assume NASA can’t make cheap launch or cheap depot. NASA can make mistakes, and one can learn from mistakes and get “real data”.
          An experimental shuttle could fly payloads, and experimental depot could transfer rocket fuel. But was mistake to think Shuttle could fly military payloads and I think it’s a mistake make to make depot store LH2.
          I also don’t NASA should plan on Lunar base, if after NASA explores the lunar poles and get real data- and one gets investment dollar spent because real date shows it could be minable lunar water, AND Congress is throwing money at NASA to build a lunar base while its in the middle of a Mars exploration program- then with the extra funding given, NASA can build the congressional lunar base.
          Likewise, a LOX depot could lead to storing LH2

    1. It is good to see deficits finally becoming an issue for the media and the Democrats but any attempt to lower spending will be fought tooth and nail by both. Too bad it comes with collective amnesia of the last 18 years.

      I suspect we will see things like any cut to NASA portrayed as horrible but any proposed spending increase as not enough.

      I’m not certain that a “serious stab” or “giant leap” is the right path to take. People have nostalgia for Apollo but small incremental steps that allow for building knowledge and taking advantage of rapidly changing capabilities of the private sector is a better way to go. What concerns me is that it isn’t clear if the proposed lunar missions will be in the mold of COTS and CCDEV. The private sector has the ability to do both crewed landers and robotic rovers and some of these companies even have a business case.

      1. The disaster will occur if interest rates spike a lot. The built up national debt will become very difficult to sustain. Hyperinflation is not out of the question at some point.

        1. No Western nation seriously intends to pay its debts. They will simply be eliminated, either through default, or hyperinflation.

          Assuming that AI and automation doesn’t eliminate the economy first, of course.

        2. Yes, and every time the Fed has tried to raise interest rates, it caused the market to drop. This shows the market is not as strong as people have been claiming these last five years or so. The Fed has trillions of dollars on their balance sheet they want to get rid of but who knows how?

          Both parties should realize that the money spent servicing the debt prevents them from taking care of the programs they claim to care about. The media never talks about it. Drudge is the only one that pointed out that record tax revenue still came with deficits. The public doesn’t know about it unless they do their own research.

          The only way to deal with it is by cutting spending, but then we will all die, especially women, children, minorities, and the elderly.

  4. “… lacking heat shielding sufficient to withstand an Earth return from any significantly more distant point…”

    Is that true? Earth velocity about the Sun is about 19 miles/sec (which I remember from the Galaxy Song). Earth is at 1 AU, Mars at 1.5 AU. Vis-Viva says the ratio of perihelion velocity, at Earth for an orbit with Mars aphelion, to Earth velocity is about sqrt(2-2/2.5) := 1.096, the difference being 19*0.096 := 1.8 miles/sec. The Space Shuttle deorbited at about 17,000 mph or 4.7 miles/sec.

    I mean, sure, timing is everything, but it seems doable on the surface.

  5. If Elon is going to come anywhere near his planned timeline for Mars missions, he needs to be developing (or, more likely, hiring somebody to develop) designs for the base, rover(s), ISRU/power plant, and all of the associated hardware that will be needed on the initial launch window to be ready for the crewed mission 26 months later. He’ll also need a landing site–and if he plans to build a base there, and use rovers and/or ballistic hops (entirely possible with BFS and a supply of local hydrogen, i.e., water) to explore the rest of the planet, then he needs a site that provides everything from accessible water to soil low in percholates.

    Has anyone heard of any work by SpaceX in these areas?

  6. Eric Berger has looked at it, and (unsurprisingly) the Trump administration seems to be in no hurry to get back to the moon.

    Who was that guy who always said space wasn’t important?

    The proposal is for NASA to get a bit more money and the future of NASA down to the daily workflow a decade from now still hasn’t been decided. This is a good thing considering how much things will change over the next few years. A giant leap toward the Moon might require a rather small investment from NASA.

    For me, the big questions are:
    – Will SLS be cancelled?
    – What will replace the ISS?
    – What do our international partners want to do?
    – What does the private space industry want to do?
    – Will a COTS/CCDEV approach be used for replacing the ISS and lunar missions?

    For now, NASA will just keep doing what it has been doing. We have status quo, but depending on how those questions are answered, we could have radical change and not just for NASA.

    1. For me, the big questions are:
      – Will SLS be cancelled?
      – What will replace the ISS?

      I would move ISS to a high earth orbit, And not have anything in LEO in a 51 degree inclination.
      Just in terms of moving ISS higher, does anyone think that worth say 2 to 3 billion dollars. And if someone will move it for around that cost should they be paid to do it.
      So putting in orbit that doesn’t require re-boosting, which has already cost more 100 tons of rocket fuel to do over ISS lifetime. Or in terms of cost, more 3 billions dollars to do.

      Another another thing is ISS about 500 tons and to lift a ton of anything to orbit say, costs at least 3 million per ton- 500 tons being 1.5 billion dollars [though total cost about 150 billion]. Is worth 1.5 billion where it is and/or would be worth more in higher orbit.
      Anyhow within 4 years, I think something should done with ISS and don’t think that should include de-orbiting it.

      1. Doesn’t raising the orbit of ISS high enough not to require regular reboosts result in unacceptable radiation levels for the crew?

        And it’s still in the wrong orbit, unless you’re Russian.

        1. “Edward M. Grant
          February 13, 2018 at 11:05 AM

          Doesn’t raising the orbit of ISS high enough not to require regular reboosts result in unacceptable radiation levels for the crew?”

          Well generally I thinking of putting ISS above Van Allen Belts, but putting ISS above Van Allen Belt will have more radiation than LEO.
          Right now ISS gets about 1/2 of GCR [Galactic cosmic rays] as a trip to mars- 12 months of travel to mars is equal to 6 months for crew of ISS. Plus ISS gets same type of radiation one get in Van Allen belt- a slower high speed particle. I believe for ISS GCR is more significant than other radiation. Though if put ISS in Van belt belt that radiation would be increase a lot- or you only getting a little bit of Van Allen belt type radiation in LEO.
          So if going to move ISS higher, one needs more radiation shielding for crew- and shielding against GCR is different than van Allen radiation. But one could design sheilding which reduces Van Allen, solar flares and GCR radiation. Or solar flare shelter is dealing similar type of radiation as Van Allen. And solar flare can kill you, as could enough time in Van Allen.
          So shielding that worked for solar flares and CMEs, btw:
          “One can think of the explosions using the physics of a cannon. The flare is like the muzzle flash, which can be seen anywhere in the vicinity. The CME is like the cannonball, propelled forward in a single, preferential direction, this mass ejected from the barrel only affecting a targeted area. This is the CME—an immense cloud of magnetized particles hurled into space.”

          Shielding working for that and GCR would also work for Van Allen radiation.
          One wouldn’t want say + 1000 km high circular orbit which in Van Allen with it’s radiation and it being hard orbit to get to, and de-orbit from, and from it harder to get to higher orbit.
          Perhaps it could be something like a 600 km orbit. But I was thinking of putting above 20,000 km and having more shielding added. And it seem ideal to put it at something like Earth/Moon Lagrange point 1 or 2.
          At moment and for next several years we will be in solar min- which means less drag from atmosphere. Or in a period of Solar Max there is more atmospheric drag. And during solar min, one will have more GCR [and Solar Max, less GCR].
          In terms of political thinking atmospheric drag would off radar, though idea of having more radiation shielding- or politics being dumb and short sighted- might seem important.

          I think we should keep ISS and I think we should explore the Moon and than Mars. I think we explore the Moon and keep ISS the way it is, but unlikely to explore Mars and not change ISS. And I think keeping ISS in low earth orbit, is eventually death to ISS.
          NASA plans on de-orbiting ISS, and I think that is bad idea.
          Or there is no plan to keep ISS forever, and I think we should have a plan. But plan isn’t that NASA should spend 3 billion per year, forever. Need to keep ISS, but not keep NASA ISS program Whereas NASA just looking at ISS as NASA program and want to keep that program going.
          I am going with idea that it’s actually an international space station.

  7. Really like the first half of Dick Eagleson’s op-ed. SLS and FH are largely out of public view. No one cares about either. But the FH launch got a lot of press and part of that was comparisons to the Saturn V and SLS. What was missing from analysis in the popular press, economics. How many FH launches could be purchased for the cost of one SLS and how many FH launches could be purchased with SLS’s yearly development funds?

    But the second half? Proposing ways to save SLS is a bad idea no matter how cool and capable the massive franken rocket would be.

    1. I’m far from entirely unsympathetic to your reservations anent saving SLS in any way. But I saw my proferred scenario as a way to turn a sow’s ear into at least a dacron purse if not a silk one. It also downsizes NASA a bit, gives USAF something it could definitely use and messes seriously with the political nexus behind SLS. Of course the whole thing is premised on Pres. Trump publicly indicating an inclination to cancel SLS in the 2020 timeframe. I have no basis upon which to handicap the odds of that happening. But I think SLS is no longer sailing smooth seas.

      1. My hunch is we are stuck with SLS until New Glenn is a reality because of appeals to redundancy.

        The SLS development costs are a big drain on NASA but minuscule in the federal budget. The only thing that would get congress to care, is their constituents caring. I’ve found that people are very open to changing their views on the SLS if you explain to them the operational differences between SLS and FH along with the opportunity costs of continuing SLS but its not like they are going to go protest or anything.

        1. New Glenn is a competitor for FH. It’s appearance could be expected to have roughly the same impact on SLS as FH is, another sizable foreshock, but not The Big One that takes down SLS in fee simple.

          At best there will be a modestly enhanced effect because NG’s debut will usher in the meme that, “Gee, another damn billionaire built another damn big rocket in his garage! How hard can building a big rocket be? NASA, what is your problem?

          The last straw is going to be when BFS starts Grasshopping. If that happens before EM-1, SLS may well never fly. If it happens after EM-1 but before EM-2 or Europa Clipper, SLS could become a one-hit wonder.

  8. The Eagleson article contains nothing about SLS’s woes that’s news to us here. His “make the core stage be reusable” strikes me as slightly silly; it would be basically a clean-sheet design, so add another 10 years. While RS-25 was designed to be reusable (in the STS configurations) it was not designed to deal with flying nozzle-first into re-entry heat.

    NASA has too much credibility invested in SLS/Orion to cancel them before they fly. I can’t imagine that happening without the fiercest, most bloody fight. But it’s pretty clear that Falcon Heavy, and likely soon New Glenn and Vulcan, are going to make SLS look very wasteful.

    My crystal ball says SLS will be used to construct the “Gateway,” then cancelled. NASA will fly out the 4(?) sets of old SSMEs, and maybe 2-3 sets of RS-25E (point of pride to prove they could restart production) and that’ll be it for SLS. A big sign that this is going to be the case would be if NASA moves the Europa mission to Falcon Heavy, to save that core & boosters for Gateway hardware.

    But as was noted earlier, if SpaceX intends to actually go to Mars, and I believe they do, either they’ll be needing to develop a whole lot of hardware, or somebody else is going to have to do it for them. NASA could pull its chestnuts out of the fire by doing that, but it’s not a sure thing that the right kind of relationship between SpaceX and NASA can be established for that to happen.

    1. As with the non-firing Merlins on a re-entering Falcon 9, the RS-25’s on an R-SLS core stage would be shielded from the worst of re-entry heating by the plume from the central cluster of four BE-3’s. I suspect that’s less onerous a thermal environment than the one the RS-25’s faced on the aft ends of Shuttle orbiters. The velocities involved would certainly be lower.

      Outright SLS cancellation would be an ugly fight. But SLS has now been a thing for longer than its cancelled predecessor, Constellation, despite inheriting much of Constellation’s tech. The prior failure of Constellation would make any cancellation of SLS both easier to do and easier to make stick – i.e., no renamed and downsized Son of SLS as SLS was Son of Constellation.

      SLS will never be used to build the Deep Space Gateway (DSG). Every mission for that requires an Orion and crew. There is no currently planned source of additional Orion service modules beyond the two ESA is building. SLS will stand or fall long before DSG gets going in any form. If there ever is a DSG, I doubt seriously it will much resemble the mingy mishmosh that NASA has spitballed.

      Restarting RS-25E production isn’t a pride issue for NASA. It is, perhaps, a pride issue for Aerojet-Rocketdyne which is contractually obligated, at this point, to do that job. The fact is that, with the exception of Marshal Spaceflight Center and the Michoud Assembly Facility, there is no part of NASA for which SLS is a “pride issue.”

      If NASA moved Europa Clipper to Falcon Heavy it would only be because SLS Block 1A could not be ready in time to meet the launch window or because the SLS program had been cancelled. I think one or the other of these circumstances is entirely likely.

      SpaceX is developing a whole lot of hardware to go to Mars. As that project advances and gets progressively more real, more firms with applicable tech in-hand will step up.

      1. With all respect, there’s a lot of history with SLS with trying to have a 5th engine in the core vs. 4. The thermal environment is extreme. I think just sticking BE-3’s in between the RS-25’s isn’t a simple thing to do. I stick by my contention that you’re looking at a complete redesign of the core.

        I hear you, that you’re trying to give NASA a face-saving way out of this, but I don’t see a way to change course on SLS at this point. It’s built as-is, or it isn’t built at all. But I don’t see a long and prosperous future for it in any case.

        1. Yes, I suspect R-SLS would have few parts in common with today’s SLS. That’s kind of a given. I would preserve only the 8.4-meter core stage diameter as that’s what the Michoud tooling is set up for.

          It’s hardly obvious that the thermal environment at the center of the SLS core stage’s lower bulkhead is any more severe than that in the corresponding location on Saturn 5 and Falcon 9. But of course none of the engineers who designed either of those vehicles any longer works, or ever worked, respectively, for NASA. If NASA failed to keep adequate notes from the Apollo days or today’s NASA and Boeing rocket engineers simply don’t know how to do engine clustering, perhaps they could visit any of their surviving forbears and ask them what the secret is. Or, they could visit SpaceX – or perhaps even Blue Origin – and make the same inquiry. NASA needs to understand that it no longer gets undisputed credibility when it makes pronouncements about what is and is not allegedly possible anent rocket engineering.

          My R-SLS proposal was not made with any pretense of giving NASA a way to save face as it involves, among other things, amputating one of NASA’s major centers and handing the severed limb to USAF and handing the SLS to a new contractor base dominated by SpaceX and Blue Origin. I don’t think saving NASA’s face anent SLS is even in the realm of the possible.

          You’re wrong about not seeing a way to change course on SLS. You read my piece in The Space Review. The article was written precisely to lay out such a possible way. You may well regard my proposal as unworkable. I regard it, myself, as a path forward with a very low probability of occurring. That said, it is still “a way to change course on SLS.”

    1. Hi D.E.

      I enjoyed your article, but I don’t agree that SLS is in any form salvageable. The re-engineering cost given the current funding approaches used for SLS would have first to be totally revamped or they would continue to be enormous compared to the benefit. To sum it up, at some point you just can’t put a V8 Buick Wildcat engine into a Model-T Ford and shouldn’t even try.

      If you want to salvage something, maybe apply the RS25s as reusable orbital transfer engines. But that implies an in-orbit LH2 refueling capability that frankly, from a cost perspective, might not be worth it compared to carbon-based liquid fuels.

  9. There’s something about space that’s transpartisan in the worst possible way

    Do we need this word?

    I do want to send a creepy, stalkery note to Ted Cruz that consists solely of the pages dealing with the sunk cost fallacy ripped out of an old economics textbook.

    This is partially right except that you do have to look at the other part of Cruz’s statement about what the ISS can do in the future and what that will cost. Since it isn’t a business and was not conceived as one, a traditional economic evaluation isn’t really possible. Privatizing the ISS wouldn’t happen unless it had value enough to justify its existence. But due to a variety of reasons, it might not be economical for a private company to run as a business.

    The other problem is that we need alternatives to compare. None exist currently, so we don’t have precise real numbers to look at.

    We are probably stuck with ISS until there are other alternatives that people can look at. NASA could help this along with another program similar to COTS/CCDev where NASA just promises to be a customer of the winner(s). Something like having one or two astronauts year round should cost less than $300 million. They could work a competition into supporting the DSG concept. Winner gets their station moved to cis-lunar space while the loser gets to stay in LEO.

    Maybe just the promise of being a customer without a competition would work.

    Like with SLS and commercial space launchers, there would be a dual track. When alternatives exist in the real world, then it is much easier to give up the SLS/ISS.

  10. Privatization of ISS. Hm. If I were a buyer what would I consider? One possibility, attach an ion-electric propulsion unit to operate from the Solar Arrays and use that to boost it into a sun-synchronous orbit. From there I could pretty much orient the Solar Arrays so that they don’t have to work at tracking, and the electrical demand of the ion propulsion unit is now reduced to that of just stationing keeping. I’d modify it to contain a high power laser for emission in blue light at or above 441nm. Shutdown everything else except what is needed to keep thermal stability. I don’t even care if the interior is pressurized anymore, in fact I’d probably evac as much of the interior as I could get away with and still maintain thermal stability. And voila a SSPS for space use. A client satellite would send me a pilot beam and I’d respond with the laser backed up by 84 to 120 kW of juice. If your LEO satellite client has decent battery capabilities, it doesn’t need bulky solar arrays at all, just a short charge from my power sat service station. The blue laser is scattered by the earth’s atmosphere thus somewhat ameliorating fears of a space weapon, and besides beaming down 100kW of laser from 600-800km just isn’t much of threat, esp. if its scattered by the atmosphere.

    1. Not a very credible space weapon either. Since it’s passive and only responds to pilot beam request. You’d have to be *asking* for trouble. And for the truly paranoid, remember, it’s the ISS. It’s not a hardened nor hard to destroy target…

    2. “Privatization of ISS. Hm. If I were a buyer what would I consider? One possibility, attach an ion-electric propulsion unit to operate from the Solar Arrays and use that to boost it into a sun-synchronous orbit. ”
      “Typical Sun-synchronous orbits are about 600–800 km in altitude, with periods in the 96–100-minute range, and inclinations of around 98° (i.e. slightly retrograde compared to the direction of Earth’s rotation: 0° represents an equatorial orbit, and 90° represents a polar orbit)”
      So you mean a typical Sun-synchronous orbit:
      so boost to say 800 km by 300 km, change inclination to 90. Or go higher before changing inclination or what?

  11. So you mean a typical Sun-synchronous orbit:
    so boost to say 800 km by 300 km, change inclination to 90. Or go higher before changing inclination or what?

    I was thinking a boost to 800×300. A higher orbit would be helpful but probably presents serviceability problems. But really this is just a long-shot. I think serviceability is the key issue that drives the cost above what private enterprise could afford. My most serious suggestion concerning the retirement of the ISS is to park it (uncrewed) at L4 or L5 and allow it to be used for parts someday.

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