SpaceX set to try HOVER LANDING for re-usable rockets on March ISS mission
Landing legs fitted to Falcon-Dragon first stage
Gutsy call: 'We believe we have all the pieces to achieve a full recovery of the boost stage'
So they can do the hovering bit
SpaceX had an initial stab at this last September, during the proving flight of its new upgraded Falcon 9 design. Having successfully lobbed the load of satellites towards orbit, the ground controllers on that flight then attempted to bring the first stage - which was not fitted with landing legs - softly down on a precise spot in the ocean off California. On that occasion they were not completely successful, but SpaceX remains confident it can crack the problems:
For the first restart burn, we lit three engines to do a supersonic retro propulsion, which we believe may be the first attempt by any rocket stage. The first restart burn was completed well and enabled the stage to survive reentering the atmosphere in a controlled fashion.
SpaceX then lit the center engine for a single engine burn. That relight also went well, however we exceeded the roll control authority of the attitude control thrusters. This particular stage was not equipped with landing gear which could have helped stabilize the stage like fins would on an aircraft. The stage ended up spinning to a degree that was greater than we could control with the gas thrusters on board and ultimately we hit the water relatively hard.
However, SpaceX recovered portions of the stage and now, along with the Grasshopper tests, we believe we have all the pieces to achieve a full recovery of the boost stage.
Imagine not throwing all that away