Business, Space, Technology and Society

StarHopper

37 Comments

SpaceX’s live feed has started.

[Update a few minutes later]

A 57-second flight, that ascended, translated, and landed right on the bulls eye. Best water-tower flight ever.

[Update a few minutes later]

An early report from Bob Zimmerman, with pictures.

[Wednesday-morning update]

More from Bob: What Starhopper achieved.

[Update a few minutes later]

Here is Mary’s (@BocaChicaGal) video.

Here is Bill Harwood’s story.

[Afternoon update]

A drone’s-eye view.

37 thoughts on “StarHopper”

    1. If the wells feeding it had been seeping natural gas you might have seen parts of one go that high*… 😉

      *And that’s either an unsafe town to live in or a very, very, deep well for water…

      1. Its mission completed, Grasshopper is being retired. Folks in Boca Chica have their water trucked in and SpaceX needs a better water source to support their activities, so I’m betting Elon will repurpose Grasshopper as an ironic water tank.

    1. If an intact landing is removed as a requirement, could a water tower have possibly flown higher than 150 meters in mid-1940’s Japan or sometime later in New Mexico? I’m sure the AIAA’s Flying Water Tower division will want to make sure this is an actual record setting flight.

  4. Maybe today is the real beginning of the Space Age, after decades of false starts. Boca Chica is standing in for Kitty Hawk. Just a litle hop, but what comes of it…

    1. Yesterday Boca Chica’s wind speed was higher than the stall speed of the Wright Flyer.

      Even though Hopper is built out of stainless and can easily be turned into useful flatware, I’d urge them to hang on to it as a significant museum piece, maybe putting a picnic table underneath it (ala the Saturn V reproduction at Huntsville), until they come up with a permanent display option.

  5. Now on to completion of a Starship, Elon’s updated SHS presentation, a first Starship hop, launch mount construction at LC-39A and/or Boca Chica, construction of the first Super Heavy booster(s), suborbital Starship hops to space, Super Heavy hops, TPS attachment and all all-up orbital test of the whole nine yards.

    In roughly that order.

    And in less than a year, please.

    1. I am rather a cynic when it comes to SpaceX doing anything on schedule. I don’t think they can do all that in a year. I think they can in two, though.

      And if it takes two years to get Starship to orbit, it’ll still beat SLS to orbit.

  8. I noticed that the flame is blue and barely visible at altitude, but turns bright orange as it starts reaching the ground. At low altitudes, are they running fuel rich to lower the exhaust temperature so they do less concrete damage?

    1. Flame color of Boca Chica dirt the exhaust kicked up? At 0:54 it starts yellowing when they reach the tops of the dust cloud.

    2. Or something started to go wrong and it was running with an engine-rich mixture at the end; it did land a bit hard…

  9. Hmmm, that might be heating of dust in the recirculating plume. The only way we ever got a methane engine to make a yellow plume was to set off an RDX charge in the chamber… which lasted about 10 frames at 1500 FPS.

    1. Well, incomplete combustion can make methane burn yellow, which I looked into after they had a pretty good fire going after an engine test sometime prior to their first free hop, as I had been expecting a blue flame.

      It could be dust getting entrained in the exhaust stream, but I keep watching the SpaceX landing clip and comparing it to the clean liftoff plume. I’m not sure why the whole landing plume would change color so uniformly. If it was dust, I would think the flame would start blue and turn yellower further down.

      In wondering whether it is due to a mixture change, I’ll note that prior to touchdown the tanks should be nearly empty, and thus the engine should be near the bottom end of the throttle range. Could they be pretty dramatically shifting the mixture ratio to get a further thrust reduction for touchdown, dropping the ISP while maintaining stable combustion?

      Or perhaps the marketing department is sold on the sooty, used look of the Falcon 9’s? ^_^

      2. Another pure speculation, but George you may be right, it would make sense to fuel rich the oxygen pre-burner to lower its turbine temperature and allow it to cool as the engines are throttled back since it’s no doubt been running pretty hot. But I agree with Doug that I didn’t notice the flame getting really yellow until it came into contact with the landing pad.

        1. Well, my speculation that they might be lowering the exhaust temperature also made sense as something to do when the exhaust plume touches the landing pad, but as others have noted, New Shepherd has the same dust-induced exhaust plume effect.

  11. Imagine your 1Tonne online purchases arriving in such a thing. Stand aside amazon. The R2 of heavy lift terrestrial mail delivery is here. The lawn might need a tarp though.

  13. All 4 tanks atop the hopper appear to be in place. The one that went flying may have been a piece of GSE. As far as the yellow flame goes, something similar happens to New Sheppard when it lands. Special Texas Dust, I guess. I think once it’s blown into the air (that was an enormous dust cloud, not smoke, methane burns much cleaner than RP1), it would quickly be entrained back down in the exhaust plume. Anyways, it didn’t blow up. Good enough.

  15. Agreed you can see it start at 5:41 in the slo-mo and is very apparent at 5:44 in the slo-mo. Under relatively low pressure. At the upper left side of the nozzle. Looks like a methane leak. Fuel coupling come loose?

  16. It’s pretty common to spray calcium-chloride solution to control dust. The yellow-orange flair I see just for a second when it starts and then at landing could be that.

    If this is as far and as fast as it was ever supposed to go, why bother with a non structural skin?

  17. That rustic knocked-together airframe has separate propellant tanks inside- if the inner side of the visible surface held cryo propellants, it would frost up bigtime. It is not a monocoque vehicle.

  18. I’m just not seeing the things that some others are seeing in these videos. What I do see is a one or two pieces of debris flying out of a dust cloud during the last moments of the touchdown phase. What I’d like to see, if the scenario here is true, is either video of a piece visibly breaking off the hopper, or else an authoritative statement by Musk. Either one would do. I also don’t see the “big methane leak” from the engine some are talking about. I do see a plume of some kind, and like the theory that it’s exhaust from the autogenous pressurization system fitting, which is not hooked up on the hopper (if it was, there’d be no COPVs, I think). Hopefully, the facts will come out, and I’m prepared for them to be different from what I think now.

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