End of an era: Final 1st-generation Dragon returns to Earth
/The final first-generation SpaceX Dragon spacecraft has returned to Earth after its month-long stay at the International Space Station to resupply the outpost with several metric tons of cargo.
CRS-20 Dragon was released at 13:06 UTC April 7, 2020, by ground controllers at NASA’s Mission Control Center in Houston with Expedition 62 astronaut Drew Morgan observing aboard the outpost in the event he was needed as a backup.
“Thanks go out to our hardworking partners at SpaceX at the end of this first of many chapters together,” said NASA flight controller Brandon Lloyd on the ISS communications loop with Morgan concurring shortly thereafter.
After release, Dragon began backing away from the outpost and within several minutes, the spacecraft was outside the 200-meter “keep-out sphere,” and soon the 1 by 1 by 2 kilometer “approach ellipsoid.”
End of an era
The first Dragon spacecraft to arrive and berth with the ISS was the C2+ mission in May 2012. Following this test mission, the CRS-1 mission flew in October of that year. This was the first flight under the Commercial Resupply Services contract.
CRS-20 marks the conclusion of the original CRS contract as subsequent cargo missions will fly under the CRS2 contract.
In total, some 43 metric tons of supplies were delivered to the ISS under SpaceX’s CRS1 contract over 20 missions since 2012. Thirty-three metric tons were returned during that same amount of time.
Following CRS-20’s departure from the ISS, the spacecraft continued to drift away for several hours before performing a deorbit burn using its Draco thrusters. This 12-minute firing slowed the vehicle enough to drop it out of orbit.
Before entering Earth’s atmosphere, the trunk section of Dragon was jettisoned to burn up. The capsule portion, protected by a heat shield during reentry, splashed down in the Pacific Ocean, just off the coast of Baja California, having completed its third round-trip flight to space — the third Dragon spacecraft to accomplish this feat.
“Good splashdown of Dragon confirmed, completing the 20th and final [International Space Station] resupply mission for SpaceX’s first iteration of the Dragon spacecraft!” The company tweeted following a successful splashdown.
According to SpaceX, the capsule reached the water just before 19:00 UTC, some six hours after leaving the ISS.
CRS-20 launched to space atop a Falcon 9 rocket at 4:50 a.m. UTC March 7, 2020, from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida. Inside it was nearly 2,000 kilograms of cargo bound for the ISS.
The spacecraft was captured two days later on March 9 and berthed to the Earth-facing port of the Harmony module.
During its month-long stay, the capsule’s cargo was unloaded before being replaced with nearly 2,000 kilograms of unneeded equipment and experiments bound for Earth-based research laboratories.
Additionally, the Bartolomeo experiment platform, located in the unpressurized trunk section, was removed and placed on the space station’s Columbus module.
Following its departure and splashdown, the capsule was collected by a SpaceX recovery ship.
The spacecraft is expected to be returned to the Port of Los Angeles where time-sensitive cargo will be offloaded and transported to their destinations.
The capsule is then expected to be shipped to SpaceX’s test facility in McGregor, Texas, where the rest of the capsule's contents will be offloaded and the spacecraft decommissioned.
Dragon 2
CRS-20 was the final Dragon planned to be captured by the station’s robotic arm and berthed to the outpost. Subsequent upgraded second-generation Dragon 2 spacecraft are all designed to autonomously dock at international docking adapters located on the Harmony module.
Dragon 2 spacecraft are designed to send either crew or cargo to the ISS, depending on the configuration.
An unpiloted crew variant first flew to the ISS in March 2019 — the Crew Dragon Demo-1 mission. The spacecraft is set to fly with people as early as May 2020 for the Demo-2 mission.
The first cargo variant of Dragon 2 is planned to fly to the outpost is expected to be the CRS-21 mission, which is targeting launch sometime in the fall of 2020.
