• LughOPMA
    link
    English
    6323 days ago

    NASA really is stuck between a rock and a hard place when it comes to its lunar plans. Its SLS system is a disaster, but pork barrel politics means it can’t ditch it. So it lives on, zombie-like, to suck the life and money out of better options.

    Meanwhile, it’s placed all its eggs in a SpaceX basket. That company is run by someone who routinely exaggerates timelines for delivery and fails to meet them. Guess what? It’s happening again. A commenter on the OP article sums up what SpaceX has to do before humans can go back to the Moon.

    • Re-light Starship engines
    • Achieve stable orbit
    • Dock with another Starship
    • Transfer propellant
    • Use transferred propellant
    • Dock with Orion and/or Dragon
    • Design a life support system for a volume much larger than Dragon
    • Build life support system
    • Test life support
    • Achieve escape velocity for TLI
    • Demo propulsive landing on Luna
    • Demo takeoff from Luna after sitting idle
    • Dock with Gateway (?) up and down
    • FaceDeer
      link
      fedilink
      823 days ago

      That list is out of date, several of those items have already been accomplished.

        • FaceDeer
          link
          fedilink
          1423 days ago

          Re-light Starship engines, achieve stable orbit (they deliberately cut the engines just a few meters per second shy of it on IFT-3, there’s no reason not to count it), and transfer propellant (one of IFT-3’s test routines during its almost-orbit was transferring propellant between internal tanks).

          • @Player2@lemm.ee
            link
            fedilink
            English
            623 days ago

            Actually they did not succesfully relight the engines in space as planned, but they intentionally skipped the test due to vehicle conditions as opposed to it failing

            • FaceDeer
              link
              fedilink
              723 days ago

              They relit the engines on the booster, which are the same engines. They’ve been relighting engines for a while now.

              • @Player2@lemm.ee
                link
                fedilink
                English
                623 days ago

                They attempted to relight the booster, but only 1 of the 13 engines they wanted on actually started (2 others almost started but immediately failed). Their hope was to demonstrate in-space relight of the second stage engines, which is obviously a crucial demonstration for HLS and eventually going to the moon, but they never went for it. So far they have never demonstrated Raptor start in a vacuum and microgravity, which is a significantly different challenge to firing on the ground or even during re-entry as was the case for the booster due to propellant slosh and ullage considerations. In fact, we have seen them struggle with these issues in the earlier Starship solo tests, where the engines upon relight would eat backfill helium and eventually switch over to an engine-rich cycle :D. I’m sure they will figure it out but in space Raptor relights are far from the ‘same’ as what they have already done.

                • FaceDeer
                  link
                  fedilink
                  7
                  edit-2
                  22 days ago

                  They shut down and relit many more engines during stage separation and the subsequent boostback burn. Here’s where they relight the middle ring of Raptors.

                  I suppose if you want to add “in microgravity” to that list item, then yeah, they haven’t done that part yet. The list item just said “Re-light Starship engines”, which they have indeed done many times in many circumstances. Just not that particular one yet.

      • Echo Dot
        link
        fedilink
        English
        823 days ago

        The first two have been dine. But yeah, still a big list.

        • FaceDeer
          link
          fedilink
          4
          edit-2
          23 days ago

          There was a propellant transfer done during IFT-3’s flight between internal tanks, too.

          The list’s not as big as it seems, several items are very closely related (there’s three separate items for “design, build, and test a life support system” for example).