Crew Dragon Endurance and the Crew-7 astronauts returned to Earth after the handover to the Crew-8 astronauts on the International Space Station (ISS). Spacecraft commander and US Marine Corps Lt. Col Jasmin Moghbeli, pilot and ESA astronaut Andreas Mogensen from Denmark, Japanese mission specialist Satoshi Furukawa of JAXA, and Russian mission specialist Konstantin Borisov of Roscosmos undocked from the Station on Monday, March 11 at 11:20 AM EDT (15:20 UTC) for their return to Earth.
Crew-7:
The undocking follows a stay of just over six months in orbit for the crew, which has been handing over the Station to the new residents from Crew-8. Crew-7 launched in the predawn hours of Aug. 26, 2023, from the Kennedy Space Center and conducted numerous experiments during their stay on the Station.
Now the Crew-7 astronauts are focusing on familiarizing Crew-8 with the Station’s systems, life on board, and emergency procedures while also packing up their spacecraft for the ride home.
A handover ceremony took place on Sunday, March 11, where Station commander Andreas Mogensen handed over the reins to Oleg Kononenko, who will be the ISS commander until September when he returns to Earth after his approximately one-year-long mission along with Nikolai Chub.
Their Soyuz MS-24 crewmate, Loral O’Hara, will return to Earth on MS-24 along with two visiting crewmembers from Soyuz MS-25: Oleg Novitsky from Roscosmos and Marina Vasilevskaya from Belarus. MS-25 will be used to return Kononenko, Chub, and Tracy Caldwell-Dyson, who will launch aboard MS-25.
The departure of Endurance from the ISS will not mark the end of Expedition 70. The expedition will last until Loral O’Hara leaves the Station, which is scheduled for early April. During Expedition 70, Crew-7 astronauts conducted numerous experiments, including biomedical experiments such as CIPHER, which tracked astronauts’ health during their entire mission.
Crew-7 commander Jasmin Moghbeli and Loral O’Hara conducted an EVA in November to install a bearing on a rotary joint and to prepare ISS for another solar array upgrade. Another spacewalk with Loral O’Hara and Andreas Mogensen was pushed back to Expedition 71.
After Endurance leaves the Station and undocks from the Harmony module’s zenith port, it targeted for a splashdown off Pensacola, Florida on the Gulf Coast. The return to Earth concluded Tuesday, March 12, at 5:50 a.m. EDT (09:50 UTC).
Recovery ships Megan and Shannon, named after the first women to fly aboard Crew Dragon, were prepared for Endurance’s return. Megan is assigned to the Gulf Coast, sailing out of Tampa Bay, while Shannon is assigned to the Atlantic Coast and has already sailed out of Port Canaveral for last-minute training prior to the Crew-7 splashdown.
Seven sites could have been used for Crew-7’s return. These are just off Pensacola, Panama City, Tallahassee, and Tampa on the Gulf side, and Jacksonville, Daytona, and Cape Canaveral on the Atlantic side. Shannon has sailed from Port Canaveral for the last-minute training, but Megan has also sailed into the Gulf of Mexico to prepare for the splashdown. As Pensacola has been chosen, Megan will be the recovery ship.
Whichever site was chosen needed to have winds no greater than 16 and a half kilometers per hour, waves not greater than a seven-degree slope or with the same wave period and height, probability of rain less than 25 percent, and no lightning within 16 kilometers or a probability of greater than 25 percent of lightning in the area.
In addition, the recovery ship’s helicopter must pass a hover test, there can be no more than four degrees of pitch or roll on the recovery vessel, the cloud ceiling must be above 150 meters, and there must be more than eight-tenths of one kilometer of visibility in the daytime and just over one and a half kilometers visibility at night.
While Endurance is orbiting on its own, the crew will don their launch and entry suits and ensure they are prepared for the return. Just under an hour before the scheduled splashdown, the “trunk,” containing solar panels and fins, will be jettisoned, and the heat shield, made of PICA-X, will be uncovered.
The spacecraft will be moved into a position where the heat shield is against the direction of flight. The deorbit burn starts five minutes after the trunk is jettisoned and lasts for 15 minutes. Afterward, Crew-7 is committed to coming home.
After the deorbit burn is finished, it will take approximately 37 minutes for Endurance to reach its splashdown point off the Florida coast. When the spacecraft reenters the atmosphere, plasma from the reentry will block radio signals, causing a communications blackout.
After communications with Endurance resume, the spacecraft will deploy two drogue chutes and, later, four main parachutes before splashing down.
A team will sail out to Endurance and check for any leaking hypergolic fuel or other hazards before clearing the spacecraft to be retrieved by the recovery ship. Once aboard the ship, the Crew-7 members will be taken out and checked by medical personnel before flying off the ship on a helicopter.
The Crew Dragon has generally performed well during its career, with some issues reported. Among them are a slow-deploying main parachute and a failed acceptance test on a heat shield that required its replacement before a mission. SpaceX and NASA will continue monitoring the spacecraft and its safety as it continues to ferry crews to and from the Station, and the Crew-8 astronauts will pick up where Crew-7 left off.
(Lead image: Dragon Endurance in space. Credit: NASA)