first ground landing at LZ-1 succeeded in December 2015, and the first landing at sea on a drone ship in April 2016. The second landed booster, B1021, was The Falcon 9 first-stage landing tests were a series of controlled-descent flight tests conducted by SpaceX between 2013 and 2016. Since 2017, the first stage of Falcon 9 rockets are routinely landed if the performance requirements of the launch allow. 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 The Falcon 9 first-stage landing tests were a series of controlled-descent flight tests conducted by SpaceX between 2013 and 2016. Since 2017, the first stage of Falcon 9 rockets are routinely landed if the… The Falcon 9 first-stage landing tests were a series of controlled-descent flight tests conducted by SpaceX between 2013 and 2016. Since 2017, the first stage of Falcon 9 rockets are routinely landed if the performance requirements of the launch allow. 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. The second landed booster, B1021, was the first to fly again in March 2017, and was recovered a second time. flight 20 (Orbcomm OG2 M2) safely touching down on the LZ-1 ground pad upon first attempt in December 2015; flight 23 (CRS-8) achieving a stable landing at sea in the Atlantic on the drone ship Of Course I Still Love You in April 2016 after four previous attempts ended in destruction of the booster upon impact; flights 24 (JCSAT-14) and 25 (Thaicom 8) returning at higher speed from GTO missions at sea on a drone ship in May 2016; flight 27 (CRS-9) returning to LZ-1 in July 2016; flight 28 (JCSAT-16) landing on a drone ship in August 2016. 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 Archived January 15, 2017, at the Wayback Machine and CRS-10 press kits of 2017, compared with CRS-9 and JCSAT-16 Archived August 14, 2016, at the Wayback Machine of 2016). By 2017, 14 routine landings had been performed (100% success) and three missions were launched in expendable configuration, not attempting to land. The first-stage descent tests were part of the larger SpaceX reusable launch system development program, which included a large amount of new technology development activities and earlier low-altitude test flights at the SpaceX facility in McGregor, Texas in preparation for the high-altitude high-velocity testing of landing test phase of the program. The overall objective of the program is to privately develop reusable rockets using vertical-landing technology so as to substantially reduce the cost of space access. Traditionally, the first stages of orbital carrier rockets have been discarded in the ocean once the ascent was complete. Achieving routine recovery and reuse of the launch vehicles could substantially reduce the cost of access to space. SpaceX had planned to make the sixth controlled-descent test flight and second landing attempt on their drone ship no earlier than February 11, 2015. Landing a returning rocket at sea would have been a "potentially historic rocket launch and landing", as such a feat "was unheard of" five years earlier. According to regulatory paperwork filed in 2014, SpaceX plans called for the sixth test flight to occur on As of 28 January 2023, SpaceX has attempted 178 landings of a first stage on a solid surface, 167 of which have succeeded (93.8%), with 139 out of 144 (96.5%) for the Falcon 9 Block 5 version. In July 2014, SpaceX announced that the fifth and sixth controlled-descent test flights would attempt to land on a solid surface, merging the lessons from the high-altitude envelope expansion of the first four controlled-descent flights over water with the low-altitude lessons of the F9R Dev1 testing in Texas. At that time, the "solid surface" was not further described, and was later revealed to be a seafaring barge dubbed an autonomous spaceport drone ship. Many of the test objectives were achieved on the first attempt, including bringing the stage to the specific location of the floating platform and collecting a large amount of test data with the first use of grid fin control surfaces for more precise reentry positioning. However the touchdown on the corner of the barge was a hard landing and most of the rocket body fell into the ocean and sank; SpaceX published a short clip of the crash. It would take four more attempts to achieve the first barge landing at sea on flight 23. Meanwhile, ground landing succeeded on the first attempt with flight 20 on December 21, 2015. In October 2014, SpaceX clarified that the "solid surface" would be a floating platform constructed from a barge in Louisiana, and confirmed that they would attempt to land the first stage of the fourteenth Falcon 9 flight on the platform. For the landing to succeed, the 18 m (60 ft)-wide span of the rocket landing legs must not only land within the 52 m (170 ft)-wide barge deck, but would need to also deal with ocean swell and GPS errors. In late November, SpaceX revealed that the landing barge would be capable of autonomous operation and would not need to be anchored or moored; it was hence called an autonomous spaceport drone ship. As of January 2015 three of these ships had been built, two of which were operational.