SpaceX Landing Attempt Video Released

An anonymous reader writes: Last week, SpaceX attempted to land a Falcon 9 rocket on an autonomous ocean platform after successfully launching supplies to the ISS. It didn't work, but Elon Musk said they were close. Now, an amazing video has been recovered from an onboard camera, and it shows just how close it was. You can see the rocket hitting the platform while descending at an angle, then breaking up. Musk said a few days ago that not only do they know what the problem was, but they've already solved it. The rocket's guiding fins require hydraulic fluid to operate. They had enough fluid to operate for 4 minutes, but ran out just prior to landing. Their next launch already carries 50% more hydraulic fluid, so it shouldn't be an issue next time.

Comments

Re:Wait a minute

[scarpa]

It's an open loop system, presumably to save mass.

Re:Wait a minute

[Anonymous Coward]

Others are posting about an open system. Besides the loss of the hydraulic fluid which would lighten the load you should also consider that to make a closed loop system it would add mass in the parts and tubes which would be required to contain and create the closed loop.

Re:Wait a minute

[LWATCDR]

I wonder if they are using a pressurized accumulator for the fins instead of a pump. Still a bit odd since the air flow that close to landing should have been next to zero and one would assume that they still had thrust vectoring on the main engine.

Fins went hard-over when the system ran dry.

[robbak]

Elon stated while being questioned last week that the steering fins went hard-over (which means they were driven to their maximum angle) when the fluid ran out. With the fins pushing the rocket over, it didn't have much hope of landing. And, yes, a pressurized accumulator is the most likely design of this system.

/u/DixieAlpha over at reddit programmed a Kerbal Space Program model to try to land with grid fins fixed at 30 degrees. The results were scarily similar to this landing.