14 thoughts on “SN5”

  6. Outstanding! Can’t imagine how fast that thing will pop up with three engines for the 20k flight.

    Time to sprout some control surfaces.

  7. That was truly impressive. From the pieces blasted off the test stand to the tail-slide, and the apparently out of plumb landing, so many things could have gone really wrong. They made it happen regardless. Kudos to the SpaceX team. I hope I can get down there for a future test flight.

    1. There were a few things that looked very abnormal in that video. First, the rocket began moving laterally very soon after liftoff. It looked like that was much too soon to begin the move. It reminded me of the very first Falcon 9 launch that did a roll maneuver immediately after liftoff. Then, a big piece of something, perhaps part of the launch pad, can be seen tumbling through the air a few seconds later. That might be related to the early lateral move. Then, at about the 40 second mark of the video, it appears flames are visible on the outside of the engine bell. All of these things can be fixed, but they sure didn’t look normal to me.

      1. Larry, don’t forget that the single engine was intentionally not installed on the center-line of the vessel so it was going to have to do that tail-slide in any case to move the thrust line under the CG. Seems unlikely that the attitude control thrusters could overcome that imbalance by themselves. It was pretty dramatic.

      2. The lateral move was intentional (I believe they wanted to make sure it did not land back on the launch pad), but I can’t think the flames on the top of the Raptor were. Probably a small leak in a methane line somewhere – but not a big deal.

        1. I was discussing this on the LabPadre Discord page the other day, and suggested that it was the result of a very small amount of methane leakage from a shaft seal, since high-speed rotating shafts with crazy temperature ranges and high-pressure gases are notoriously difficult to cope with. The realistic goal is really just to minimize the leak rate, not eliminate it entirely, and then safely dispose of the low-volume, low-pressure leakage.

          Someone else looked at the videos and the engine diagrams and said “Yep. Looks like it’s coming from the fuel turbopump.”

  9. Very cool. Yes looked like a minor methane leak in the engine lines and something tore loose on the launch pad and ignited some free methane and sent some debris flying. But all-in-all I think you have to chalk this one up as a success.

    Elon says there will more more of these same tests before an all up finned vehicle test. I think that’s a good idea.

    https://twitter.com/elonmusk/status/1290826885375696899?s=21

  10. For me, the main takeaway is not that they got an obsolete prototype flying, its that SN5 with a full complement of engines, is a working expendable upper stage for Super Heavy. It’s Starkicker, and with the lower stage (no harder to build than SN5) couple put 200 metric tons in LEO for no more than Falcon 9 costs to put 20 tons. You could orbit a space station the size of the ISS USOS in one shot (provided you could fold it up neatly, so more likely Super-Skylab). Or, you could stack a fully-fueled National Team HLS (tug, lander, and ascent stage), complete with Orion, LES, and crew on top, and send it through TLI.

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