2007 March 21 - 01:10 GMT - Launch Vehicle: Falcon. LV Model: Falcon I . Falcon 1 2 FAILURE: Liquid oxygen slosh in the second stage created an oscillation, putting the stage in an uncontrollable roll, starving the engine from propellant. DemoFlight 2 Agency: DARPA. An oscillation appeared in the upper stage control system 90 seconds into the burn. This instability grew and after 30 seconds induced a roll torque that exceeded the control capability of the second stage roll control thrusters. The propellants were centrifuged away from the outlets, causing flame-out of the Kestrel engine. LOX slosh was believed to be the primary contributor to this instability. Second stage slosh baffles would be included in future boosters to prevent reoccurence of the problem.