NASA astronauts Butch Wilmore (right) and Suni Williams, wearing Boeing spacesuits, depart the Neil A. Armstrong Operations and Departure Building at Kennedy Space Center for Launch Complex 41 at Cape Canaveral Space Force Station in Florida to board Boeing’s CST-100 Starliner spacecraft for a crewed test flight, June 5, 2024.
Miguel J. Rodriguez Carrillo | AFP | Getty Images
With NASA astronauts staying on the International Space Station much longer than planned, agency leadership on Wednesday acknowledged there are potential alternatives to Boeing’s Starliner to return crews to Earth.
However, Boeing’s spacecraft remains the primary option for crew return, officials said.
The Starliner Calyps capsule could return from its extended stay at the International Space Station by the end of this month, pending the results of testing a faulty propulsion system, officials said. The Starliner has now spent 36 days in space and is still going strong, with the agency and Boeing conducting additional tests in New Mexico before clearing the spacecraft to return.
This mission is the first time that the Starliner spacecraft has carried NASA astronauts, Butch Wilmore and Suni Williams.
“The first option today is to get Butch and Sonny back on Starliner,” NASA’s commercial crew director, Steve Stich, said during a press conference, adding that “we see no reason” at this time to switch to the agency’s other transportation option, which would be SpaceX’s Crew Dragon, to return the astronauts.
Stich — while acknowledging that SpaceX’s capsule could be part of contingency plans in case Starliner returns from the ISS empty — noted that NASA doesn’t yet need to “make a decision about whether we need to do anything different.”
“We’ve certainly dusted off some of those things to look at in relation to Starliner, just so we’re prepared in case we have to use some of that kind of stuff,” Stitch said.
“[But] “There was really no discussion of sending another Dragon to rescue the Starliner crew,” Stitch later added.
SpaceX’s Crew Dragon “Endeavour” capsule as seen from the International Space Station on May 2, 2024.
NASA
Boeing and NASA began testing the spacecraft’s propulsion technology on the ground in White Sands, New Mexico, on July 3, aiming to replicate the problem that caused up to five of Calypso’s thrusters to shut down during a docking maneuver with the International Space Station. The ground test is being done “to make sure that with all of these pulses and all of the heat we’re putting into it, it’s not causing any damage to the engine,” Stich said.
Stich said Starliner’s return “at the end of July” is “optimistically” dependent on the completion of testing. Boeing and NASA teams at White Sands are conducting inspections of the test booster over the next week.
But “so far we haven’t been able to replicate the temperatures we saw in flight,” Mark Nabi, Boeing’s vice president of Starliner programs, said during the press conference.
“What we’re trying to do with this test is fill in some gaps because…what we’re trying to do is understand whether the propulsion motors are working properly. [as expected]“If that happened, we would be able to separate and come back. And if the thrusters were damaged in some way, what would we have done differently?” Nabi said.
“We don’t think we damaged the thrusters, but again, we want to fill in the blanks and do this test to make sure ourselves,” Nabi added.
Pictured, Boeing’s Starliner spacecraft docks with the International Space Station orbiting over Egypt’s Mediterranean coast on June 13, 2024.
NASA
Speaking to the press from the International Space Station, Wilmore and Williams expressed confidence in returning aboard the Starliner.
“We trust that the tests we are running are the tests we need to get the right answers that give us the data we need to go back,” Wilmohr said.
Starliner was once considered a competitor to SpaceX’s Dragon spacecraft, which has made 12 crewed flights to the International Space Station over the past four years. However, various setbacks and delays have steadily pushed Starliner into second place for NASA, with the agency planning to alternate flights with SpaceX and Boeing astronauts.
The Starliner crew flight test represents the final major step before NASA certifies Boeing to fly crew on six-month operational missions starting in February.
