WASHINGTON — A Crew Dragon undocked from the International Space Station April 24 carrying four private astronauts who spent nearly twice as long on the station as originally planned.
The Crew Dragon spacecraft Endeavour undocked from the station at 9:10 p.m. Eastern. The undocking sets up a splashdown off the Florida coast scheduled for 1:06 p.m. Eastern April 25. While SpaceX has several potential landing sites to choose from, NASA said the primary site is in the Atlantic Ocean offshore from Jacksonville.
“Thanks once again for all of the support through this amazing adventure that we’ve had, even longer and more exciting than we thought,” Michael López-Alegría, commander of the Crew Dragon spacecraft, told space station controllers once the spacecraft departed the vicinity of the ISS shortly after undocking.
The undocking marks the final phase of Axiom Space’s Ax-1 mission, which started with an April 8 launch on a Falcon 9 from the Kennedy Space Center. The mission, the first private astronaut mission by a U.S. spacecraft to the ISS, is commanded by López-Alegría, a former NASA astronaut, with three customers: Larry Connor, Eytan Stibbe and Mark Pathy.
Endeavour docked to the ISS April 9 for what was originally billed as an eight-day stay. However, the spacecraft spent more than 15 days at the station, its departure delayed primarily by poor weather at splashdown locations. Neither NASA nor Axiom Space elaborated on the specific weather criteria, like winds or wave conditions, that prevented a splashdown, other than “marginally high winds” that delayed the undocking from April 23 to April 24.
The extended stay did not materially affect station operations. “NASA and Axiom mission planning prepared for the possibility of additional time on station for the private astronauts, and there are sufficient provisions for all 11 crew members aboard the space station,” the agency said in an April 20 blog post.
It did raise questions, though, about whether it would cost Axiom and its private astronaut customers more money. “The agreement between NASA and Axiom allowed for the possibility of extra days,” Axiom spokesperson Dakota Orlando told SpaceNews April 24, but did not answer questions about the details of that agreement.
NASA spokesperson Stephanie Schierholz said April 24 that the agreement included an “equitable balance” to cover delays. “Knowing that International Space Station mission objectives like the recently conducted Russian spacewalk or weather challenges could result in a delayed undock, NASA negotiated the contract with a strategy that does not require reimbursement for additional undock delays,” she said.
The additional time on the station didn’t go to waste. The four private astronauts had a “tightly packed research schedule,” Orlando said, at times working 14 hours a day. “With the delay, they have continued working on these research and outreach projects at a more leisurely pace, with additional time to enjoy views of the blue planet.”
Before the launch, Axiom executives emphasized the research they would do over the sightseeing that the station would offer. “They’re not up there to place their noses on the window. They really are going up there to do meaningful research,” said Michael Suffredini, president and chief executive of Axiom Space, at a briefing about the mission in February.
The undocking was not affected by an ISS maneuver April 23. The Progress MS-18 spacecraft docked to the station’s Russian segment fired its thrusters for 10 minutes and 23 seconds to increase the station’s orbit by about two kilometers. NASA advertised the maneuver as one that “optimizes phasing for future visiting vehicles arriving at the station,” but was originally described as one to avoid a piece of debris projected to come close to the station.
NASA spokesperson Gary Jordan said that while flight controllers were tracking a potential conjunction, or close approach, of debris to the station, “the conjunction went green,” or no longer posed a threat. “Flight control teams elected to proceed with a nominal reboost,” he said.
The debris in question, Jordan said, was an object with a NORAD ID of 51157, and is one of more than a thousand pieces of tracked debris created by Russia’s antisatellite weapon demonstration in November 2021 that destroyed a defunct Russian satellite, Cosmos 1408.