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Longer Video Shows How Incredibly Close Falcon Stage Came To Successful Landing
Bruce Perens writes In the video here, the Falcon 9 first stage is shown landing with a tilt, and then a thruster keeps the rocket vertical on the barge for a few seconds before it quits, followed by Kabooom with obvious significant damage to the barge. It looks like this attempt was incredibly close to success. Given fixes, a successful first-stage recovery seems likely.
You can see a lot more if you go to 1080 HD and full screen. There's some large piece of equipment, perhaps the motor head for one of the barge's corner thrusters, being thrust off of the barge in flames.
It looks like they'll need to do a lot of work on the barge. The support ship Go Quest and the tug Elsbeth III seem to be back in Jacksonville according to vessel tracking sites. There is a Carnival cruise ship that parks next to the barge's dock every 4 days, so we will probably see photos from its bow netcam if we don't see them otherwise.
Oh, check out this newscast. At 2:43, CBS News uses a sequence a SpaceX fan produced with Kerbal Space Program to illustrate how the landing is supposed to work.
Bruce Perens.
The pad area they have at KSC...
The Kerbal Space Center?
"Violence is not the answer. Violence is the question. The answer is yes."
The forces required are enormous, and even 10m away the rocket thrust would toast most materials. It still has to be caught in a specific orientation to minimize stresses, which means stabilization. As for stopping further, a 10m fall would probably far outstrip the capacity of the structure. (For comparison, more heavily built high power / amateur rockets are designed for touch down forces equivalent to a drop of about 2 meters). The fuel difference is near zero since the full motion of the rocket must be arrested prior to that final "fall".
It also means that the rockets could never land on an arbitrary location, which would be a future goal. Solving it now is a Good Thing (TM).
Is it just my observation, or are there way too many stupid people in the world?
Hard to splash down on the moon, Mars, asteroids and just about everywhere else we want to go. We'll have to get it right eventually, might as be now. Bonus benefit: cheaper than overhauling the engines every time. You'd think with them doing this at a third the cost of anyone else, WITH A PROFIT, that people would understand that they know what they're doing. Yes, there will be early failures, but this doesn't add that much cost, especially considering long term payoff.
Watch for Penguins, they eat Apples and throw rocks at Windows.
That would be hot for an aircraft, but it was the planned vertical speed profile for the rocket. The grid fins need speed to work and they are the main control surfaces. The cold gas thrusters don't have infinite gas behind them and the engine burns are very short.
Bruce Perens.
The full tweet was as follows:
@elonmusk: @ID_AA_Carmack Looks like the issue was stiction in the biprop throttle valve, resulting in control system phase lag. Should be easy to fix.
They hit a barge in the middle of the ocean with a gigantic rocket that was nearing orbital velocity. I think we need to cut them some slack :)
The F9 is intended to land with what they call a "Hover Slam" maneuver - the engines decelerate it to zero right above the surface in as little time as possible. The Merlin engines have a limited throttle range, and with the stage empty, just one engine firing at the lowest throttle setting has a thrust-to-weight ratio somewhere around 1.8, so it can't hover. It would decelerate to zero and then start to lift off again if the engine isn't shut off, you'd need a TWR of 1.0 to just counter gravity and make it hover.
This
You think landing on a body 1/6 of Earth's gravity, without an atmosphere or weather, and under the control of a human is really comparable to landing on Earth, with full gravity, atmospheric weather systems, and all controlled by a computer?
Certainly looked that way to me. On the last oscillation before touchdown, with the tail end moving towards the left, the thrusters keep pointing the same way as the rocket goes through vertical and only change direction a little bit afterwards. This increased the amplitude of the oscillation rather than decreasing it. The thrusters should have changed direction before passing through vertical, not afterwards. I can't imagine them getting this wrong in software, it's basic dynamic stability 101, so a sticky valve seems likely.
The rocket ended up landing almost perfectly vertical, but still rotating so the base was traveling sideways over the landing pad. No way they could stay upright like that.