SpaceX Falcon 9 booster post-mission, controlled-descent, test program
The Falcon 9 first-stage landing tests were a series of controlled-descent flight tests conducted by SpaceX between 2013 and 2016. The program's objective was to reliably execute controlled re-entry, descent and landing (EDL) of the Falcon 9 first stage into Earth's atmosphere after the stage completes the boost phase of an orbital spaceflight. The first tests aimed to touch down vertically in the ocean at zero velocity. Later tests attempted to land the rocket precisely on an autonomous spaceport drone ship (a barge commissioned by SpaceX to provide a stable landing surface at sea) or at Landing Zone 1 (LZ-1), a concrete pad at Cape Canaveral. The first ground landing at LZ-1 succeeded in December 2015, and the first landing at sea on a drone ship in April 2016. A landed booster, B1021, first flew again in March 2017, and was recovered a second time.
The first landing test occurred in September 2013 on the sixth flight of a Falcon 9 and maiden launch of the v1.1 rocket version. From 2013 to 2016, sixteen test flights were conducted, six of which achieved a soft landing and recovery of the booster:
Since the January 2017 return to flight, SpaceX has stopped referring to landing attempts as "experimental", indicating that they have become a routine procedure (see Iridium-1 and CRS-10 press kits of 2017, compared with CRS-9 and JCSAT-16 of 2016). As of 3 June 2017[update] five landings have been performed (100% success) and two missions were launched in expendable configuration, not attempting to land.
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