SpaceX Catching Starship and Booster for Ten Times the Launch Rate

Elon Musk has shared SpaceX simulations of the catching of the SpaceX Starship and booster.

Being able to make the Mechazilla SpaceX catch system will enable SpaceX to a launch, land and relaunch three times a day.

A normal landing, maintenance, craning the booster and starship onto crawlers and moving 1 mph via crawler would mean about one or may two launches a week.

14 thoughts on “SpaceX Catching Starship and Booster for Ten Times the Launch Rate”

  1. In the new animation SpaceX just released (I think that's what you are referring to also?) I noticed that they depicted the booster hovering in place between the arms, just shy of contact, for a good couple of seconds or more before contact and engine shutdown. Time enough for the arms to make adjustments if necessary?

    It's definitely going to be exciting. I'll be surprised if the first attempt, or even the first few, doesn't go boom. I'm pretty sure they can make it work. I'm less sure that it works well enough to become SOP, though I think there's a reasonable chance.

  2. Sure, system shown only appears to require +/- 15 degrees or so of angular position accuracy. But this trades off on position of the center, it could be pretty ugly if one of the pins landed on the track, and one didn't; Gotta be perfectly centered at maximum angular error.

    The arms can move, of course, and it's not clear how rapidly. It's possible that the tower can track the incoming rocket and adjust the arm positions to match. Though it takes extreme forces to move anything that big rapidly, the booster is going to be moving somewhat predictably as it's coming in, it isn't capable of really rapid sideways acceleration.

    I have to think they're going to try that catching system with a short hop at some point, just to iron out the bugs. It's going to be exciting to watch that first catch.

  3. From what I understand the concept does not require the pins to be precisely positioned on landing. There are moving tracks (sort of like conveyor belts) on the top of the catch arms so that the booster / Starship can be oriented precisely after it has been caught. I don't know what the margin for error is but presumably as long as the pins end up somewhere on the tracks on top of the catch arms, that should be all the precision they need. By moving the tracks independently the vehicle can be rotated with the precision necessary for re-stacking. Or that's the idea as I understand it.

  4. Yes, the Starship's fins are not as well suited for catching as the grid fins on the booster. This allows them both to be caught by the same mechanism. But the landing accuracy will have to be rather amazing.

    Nobody has achieved that sort of precision since the Thunderbirds.

  5. Thanks for pointing out those pegs. I did not notice that detail, and I believe that all the explanations I have read have said the catch would use the grid fins. Now I understand why you wrote that landing on the grid fins would be a fallback option.

    Expecting to catch the rocket on those pegs seems to greatly increase the precision in positioning that would be required of the rocket, especially the rotational positioning, as compared to what would be required if the catch was by the grid fins. Sub-meter precision, indeed!

    I suppose using the pegs would avoid putting forces from the landing on the mechanism that is used to move the grid fins to control the booster during the descent. I did not think of that before now.

    I guess similar pegs would be needed on the Starship, rather than catching it by the upper set of fins.

  6. Do you understand that the plan SpaceX filed with the government for the first full-stack test has both the booster and the Starship landing in the ocean? So in that sense, they are NOT relying on this system of catching the rockets for landing in at least the very first test — therefore it is not holding up progress. Since they have not yet done static firing tests of the booster, they are not yet ready for a launch test, anyway.

    Even if the catching system doesn't work in early attempts, they will get loads of useful information from the booster and Starship from the whole rest of the flight, so those tests would not be wasted effort. The way I see it, there is no reason not to attempt to catch the rockets as the landing method, given that it appears that is their first choice for how the system should work. If it turns out that they are not able to make the catching system work reliably, I have no doubt they would switch to some other technique.

  7. I'm not sure why Musk is putting so much emphasis on this concept, as it's likely the least critical path that needs to be developed to make the entire Starship concept work. The easiest thing to up the launch rate is to build more boosters. They haven't even been able to launch a full stack launch yet. Relying on this over-complicated system this early in the development process seems like an unnecessary risk.

  8. If you look at the video closely, the booster is actually landing on pegs extending out from it's sides just below and between the grid fins.

  9. Well, I'm not sure I want to require anything more than a flat pad to land SS returning from orbit. Maybe tankers could be caught. A giant pillow!

  10. For the tanker variant of the Starship, it seems to me that the payload is taken on only by refueling. So that would work out well for the tanker to be caught and immediately put on top of a booster, if a booster were standing there waiting.

    For other variants of the Starship, for cargo or spacecraft to be launched, perhaps SpaceX would create a sort of payload container that would be loaded somewhere near the launch tower on its own schedule, rolled over to the tower on a short railroad-like track, lifted up to the Starship cargo bay by the chopsticks or by another mechanism that runs on the tower, and set into the cargo bay.

    Or maybe instead of a payload container, entire Starships would be put into a staging area where they would be loaded on their own schedule with whatever cargo or spacecraft they would carry, and the whole loaded Starship would be rolled over to the tower on a railroad-like track, to be lifted by the chopsticks and set on top of the booster.

    A landing Starship would be caught and put on the railroad thing to be moved to the staging area to get its next payload.

    Those latter two possibilities would require the chopsticks and tower to be able to lift a dry Starship + cargo. I don't know whether it is reasonable to expect the chopsticks would be up to handling that much of a load.

  11. I am having trouble understanding what you mean by "And landing on the grid fins has been reduced to a fallback option." The chopsticks catch the booster by the grid fins. So it seems to me that both chopsticks and grid fins are part of the same technique of catching the booster without it touching the ground. Did you write "grid fins" when you meant to write something else?

    From what I have seen explained, landing on the chopsticks + grid fins is the only option — there seems to be no fallback option.

  12. This looks like for the booster. There will be many more SS orbiters than boosters, and they will have to be packed with payload, not a one hour thing. If the next one is ready to be lifted with a crane, on to the booster, that would seem to work.

    "The majority of locations where disasters happen don't have commercial
    spaceports nearby, Spanjers told SpaceNews, adding that the Air Force is
    exploring a large range of landing options for rural sites."

  13. It's that 1mph that's the real killer, I expect.

    So, landing on the chopsticks is going to require sub-meter precision. I suppose that's not impossible, the larger size means that the booster will be less effected by wind, and the throttleable engines mean they don't have to hover-slam. But it's still going to be an impressive accomplishment.

    And landing on the grid fins has been reduced to a fallback option.

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