SpaceX Brings One Back
Steve Campbell December 2015
Space Exploration Technologies (SpaceX) has returned to spaceflight after a long hiatus with a spectacular success. The private space launch company successfully deployed eleven communication satellites in a text book space launch for ORBCOMM that was as near to flawless as makes no difference.
In a secondary, but historic mission goal, they brought back an orbital-class first stage rocket to its departure point and landed it intact. Figure A is a photo of the returned first stage at its landing zone in Florida. The full video (see Reference #1 – below) should not be missed.
Figure A: Falcon Nine First Stage Landing
Decades in Imagination, Years in the Making
The “fly-back booster” is not a new idea. Engineers have long thought that the “beer-can” approach (use once and throw away) was not an optimal solution, to say the least. Their aim was to eventually adopt a “beer stein” approach that reused the hardware and only required fuel and maintenance between flights. As for how long ago this idea was considered, the “beer” analogy should give you a clue. That particular terminology came from Werner von Braun and his team of German Rocket Engineers. That is to say about 1945-1960.
The Space Shuttle accomplished this, at least in part by reusing the orbiter with its three main engines that were a part of the first stage and the solid rocket boosters that parachuted into the ocean, to be retrieved and reused.
The SpaceX accomplishment is distinct in that an entire, operating and now flight tested rocket has been retrieved. This is superior to the solid rocket booster scheme in many ways. Most notably, the Falcon 9 has not been soaked in seawater. It could in theory be launched again within a week. But, practically speaking, they will certainly want to examine this first returned stage with a fine-toothed comb to see just how much maintenance and repair might be needed.
While Musk’s company is paid by the federal government for launches of satellites and cargo to the Space Station, the reusable aspect of the launch vehicle is being developed privately and independently by SpaceX. The first actual tests of such hardware began in 2012, with a prototype landing-capable rocket stage called “Grasshopper”. It was retired after many successful tests and a successor called (F9R Dev) made just a few flights before it had to be aborted for range safety reasons (i.e., blown to bits) due to a failure in 2014.
There were two attempts to land a first stage of an actual commercial launch – again, a secondary goal to the mission of launching the satellites. The landing zone in both these cases was a station-keeping barge out in the Atlantic Ocean. Both saw the rocket descending over the barge, but both ended in failure (that “blown to bits” thing again). Before those episodes, there were several first stages brought back to simulate landings. Simulate – because the barges were not quite ready and so the stages ended up in the ocean anyway. This last and very successful landing was at an vacant Florida Air Force Air Station launch pad (not far from the launch pad) that has been reconstructed into “Landing Zone One”.
The story of this success would not be complete without some mention of the DC-XA. This was a NASA project that was distinct for its affordable and capable aspects. The project culminated in a sub-orbital rocket to demonstrate vertical takeoffs and landings. Figure B: is a screen capture from the youtube video found at the link in reference number 2, below. The video reveals not only the impressive maneuverability of the craft, but also details the ultimate fate of the one-of-a-kind vehicle.
Figure B: The DCXA Prototype – Screen Capture from Video (2)