Video: Watch SpaceX’s Grasshopper Fly Laterally

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Video Caption: On August 13th, the Falcon 9 test rig (code name Grasshopper) completed a divert test, flying to a 250m altitude with a 100m lateral maneuver before returning to the center of the pad. The test demonstrated the vehicle’s ability to perform more aggressive steering maneuvers than have been attempted in previous flights.

Grasshopper is taller than a ten story building, which makes the control problem particularly challenging. Diverts like this are an important part of the trajectory in order to land the rocket precisely back at the launch site after reentering from space at hypersonic velocity.

  • Hug Doug

    Looks like it was pretty windy, too. Does anyone know what the wind speed was during the test?

  • therealdmt

    I’d guess about 5 knots, from the right

  • therealdmt

    Very cool! I was waiting for some horizontal movement on a test. Two tests I’ve thought they should do (without having to go over 1,200 ft there at their Texas site) are:

    1) to fly the Grasshopper through a simulated airplane traffic pattern. Especially on a day with wind, this would show real control as the path through the airmass for each [fixed/straight] ground track leg would have to be adjusted to compensate for a different wind angle, as well as vary altitude upwind and on final, while holding altitude on the downwind leg. It would be a challenging exercise for sure,, but I wonder if the landing gear would survive long enough to complete it?

    2) fly from one landing pad to another, say, a thousand feet away.

    The main other thing they could do with low altitude flights (as I see it) is to explore and expand the envelope in regards to the amount of wind they can handle. This could obviously lead to a messy end for the vehicle though…

  • Hug Doug

    really? that seems to me a very light breeze. what are you basing this guess on?

  • Hug Doug

    as for your 1st idea, I doubt very much that the Falcon 9 first stage would ever need to do maneuvering like that in real life, it sounds unnecessarily complex to perform such a test. I don’t see any reasonable justification for it. as for idea number 2. that would be a fun test, especially to watch from the ground. the problem I see is that I’m not sure if they have enough room at their McGregor testing site to build a second launch pad in such a way that a lateral test to a second site wouldn’t be a hazard to homes or infrastructure around the area (fun fact: in the google earth satellite view, Grasshopper is on the launch pad). however, they certainly would have plenty of room for such a test at the Spaceport America test site, and I would be surprised if they did not perform such a test there.

  • Michael Vaicaitis

    “I doubt very much that the Falcon 9 first stage would ever need to do maneuvering like that in real life”. The second idea is the pointless one, with no “reasonable justification” for it, other than it may make for a cool video.

    The first idea of steering a pattern is much more justified and makes much more sense. On returning to the launch site the F9 first stage software will need to be ready to compensate for whatever wind attack angles it is presented with.