1. Returning the booster back
SpaceX is a private company founded in by Elon Musk. The company has more than 6,000 employees across locations, including its headquarters in Hawthorne, CA; launch facilities at Cape Canaveral Air Force Station, FL; Kennedy Space Center, FL; and Vandenberg Air Force Base, CA; a rocket development facility in McGregor, TX; and offices in Redmond, WA; Irvine, CA; Houston, TX; Chantilly, VA; and Washington, DC. SpaceX has suppliers in all 50 states.
Grasshopper, the company's first VTVL test vehicle, consisted of a Falcon 9 v1.0 first-stage tank, a single Merlin-1D engine, and four permanently attached steel landing legs. It stood 106 feet (32 m) tall. Grasshopper was also known as Grasshopper version 1.0, or Grasshopper v1.0.
The second VTVL flight test vehicle-F9R Dev1, built on the much longer Falcon 9 v1.1 first-stage tank, with retractable landing legs—made its first test flight on . F9R Dev1 was used for low-altitude test flights in the McGregor, Texas area—projected maximum altitude below 3,000 meters (10,000 ft.)—with a total of five test flights, all made during . This vehicle self-destructed as a safety measure during its fifth test flight on .
In an arrangement highly unusual for launch vehicles, SpaceX began in using some first stages of the Falcon 9 v1.1 rockets for propulsive-return controlled-descent flight tests after they completed the boost phase of an orbital flight. The over-water tests started by SpaceX took place in the Pacific and Atlantic oceans south of Vandenberg Air Force Base and east of Cape Canaveral Air Force Station.
Following analysis of the flight test data from the first booster-controlled descent in , SpaceX announced it had successfully tested a large amount of new technology on the flight, and that coupled with the technology advancements made on the Grasshopper low-altitude landing demonstrator, they were ready to test a full recovery of the booster stage.
During the launch hiatus, SpaceX requested regulatory approval from the FAA to attempt returning their next flight to Cape Canaveral instead of targeting a floating platform in the ocean. The goal was to land the booster vertically at the leased Landing Zone 1 facility—the former Launch Complex 13 where SpaceX had recently built a large rocket landing pad. The FAA approved the safety plan for the ground landing on . The first stage landed successfully on target at local time on December 21 ().
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