WASHINGTON — A SpaceX Dragon capsule returned to Earth April 7, marking the end of the final mission of the original cargo version of the spacecraft.
The Dragon spacecraft, unberthed from the station’s Harmony module earlier in the day by the station’s Canadarm2 robotic arm, was released by the arm at 9:06 a.m. Eastern. The spacecraft maneuvered away from the station and later performed a re-entry burn, splashing down in the Pacific Ocean about 500 kilometers southwest of Long Beach, California, at 2:50 p.m. Eastern.
The departure and return of the Dragon took place normally despite the ongoing coronavirus pandemic. NASA noted in its coverage of the Dragon’s departure that personnel at Mission Control at the Johnson Space Center are alternating shifts between two control rooms, so that while one is in use the other is cleaned. Some controllers at SpaceX’s own mission control center at its Hawthorne, California, headquarters were seen in NASA TV coverage wearing face masks.
The Dragon launched to the station on the CRS-20 cargo mission March 6, arriving at the station early March 9. The spacecraft transported to the station 1,977 kilograms of cargo. It returned with more than 1,800 kilograms of cargo, including the results of experiments conducted on the station.
The mission is the last under SpaceX’s original Commercial Resupply Services (CRS) contract, which NASA awarded in 2008. The contract originally included 12 flights for $1.6 billion. NASA later added eight missions to the contract. The agency has not disclosed the total value of the extended contract, but a 2018 report by NASA’s Office of Inspector General stated SpaceX was due to receive $3.04 billion for those 20 missions, near the maximum allowed value of $3.1 billion for the CRS contract.
Future SpaceX cargo missions will use a version of the Crew Dragon spacecraft the company developed for NASA’s commercial crew program. That vehicle will have 20% more volume than the original cargo Dragon but lack the SuperDraco thrusters used in the Crew Dragon’s abort system. The spacecraft will also be able to dock directly with the station, rather than be berthed by the station’s robotic arm, and splash down in the Atlantic Ocean rather than the Pacific.
The new cargo Dragon is designed for five flights, said Hans Koenigsmann, vice president of build and flight reliability at SpaceX, during a briefing in March. The most flights a first-generation cargo Dragon spacecraft made was three, including the spacecraft on the CRS-20 mission.
Those missions will operate under a second CRS contract awarded to SpaceX, as well as Orbital ATK (now Northrop Grumman) and Sierra Nevada Corporation (SNC), in 2016. The first SpaceX mission under that contract, CRS-21, is scheduled for this fall.
Northrop Grumman started its flights under the new CRS contract in November 2019, launching two Cygnus spacecraft to date under the award. SNC is building its first Dream Chaser spacecraft, which the company plans to launch in the fall of 2021. All three companies are guaranteed a minimum of six missions each under their contracts.