SpaceX Falcon 9 Statement on First Stage Engine Anomaly

Re:SpaceX Falcon 9 Statement on First Stage Engine Anomaly by ProblemFactory on Monday October 08, 2012 @12:59PM (#4627732)

I'm not familiar with the specifics of Falcon9 redundancy. But in theory, losing many engines can be completely recoverable, because all 9 engines share a single fuel tank.

Outside of atmosphere, a rocket's final speed and orbit depend on three factors: the mass of the payload, the mass of the fuel, and the inherent engine design efficiency. Notably, it does not depend on thrust. Burning one engine for 9 seconds results in a speed boost equal to burning 9 engines for 1 second.

Even if an engine fails and another one is set to reduced thrust, the fuel is still there, and can be burned by remaining engines.

Of course, this is a huge simplification, and loss of thrust while still in atmosphere or near the ground might be a problem.

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Re:SpaceX Falcon 9 Statement on First Stage Engine Anomaly by ckg on Monday October 08, 2012 @05:39PM (#4628853)

I think thrust counts to a degree, as you'll lose velocity from gravity drag if the time to orbit is too high. The degenerate case would be if your thrust is less than the weight of your rocket (i.e. not moving).

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