Why NASA astronauts are waiting to return on Boeing’s Starliner

Log entry: Day 71.

Butch Wilmore and Suni Williams are waiting. Boeing is waiting. And throughout the halls of NASA, leaders and engineers are gathering, analyzing and deliberating.

Boeing’s Starliner capsule “Calypso” has been at the International Space Station since early June, on a mission that’s been extended indefinitely as the company and NASA try to identify why multiple of the spacecraft’s thrusters failed during docking.

Those thrusters, part of the spacecraft’s propulsion system, are key to Starliner’s return from the ISS. But NASA remains uncertain of whether the capsule is safe to return with the two astronauts on board.

“Our big concern is having a successful deorbit burn — making sure that the [propulsion] system works just the way it needs to all the way through the deorbit burn. That’s why we’re looking so closely at the thruster jets and even thinking about how the larger thrusters work,” NASA Associate Administrator Ken Bowersox told reporters during a press conference on Wednesday.

NASA has already adjusted the schedule for the next SpaceX launch of astronauts headed for the ISS, but it needs to make a decision soon on returning Starliner crewed or empty — or otherwise further delay its current plans. If Starliner comes back empty, SpaceX would serve as the rescue option for returning Wilmore and Williams.

Bowersox said a final round of data analysis is expected to be complete by Aug. 23, which would lead to NASA conducting a Flight Readiness Review, the deciding moment for how Starliner returns.

Boeing has made its case to NASA for why the company is confident that Starliner is safe, going so far as to make public appeals about the amount of thruster testing that’s been done. But the final decision that’s expected before the end of August will be NASA’s call and may go as high as its chief, Administrator Bill Nelson.

Originally intended to last about nine days, the Starliner crew flight test was supposed to be a final box checked for Boeing and a key asset gained for NASA. The agency was hoping to fulfill its dream of two competing companies — Boeing and SpaceX — flying alternating missions to the ISS.

Instead, the flight test is further setting back Boeing’s progress in NASA’s Commercial Crew program and, with over $1.5 billion in losses absorbed already, threatens the company’s future involvement with it.

As for the astronauts themselves, the head of NASA’s spaceflight safety office, Russ DeLoach, stressed that Wilmore and Williams will do “their job as astronauts,” trusting in the agency’s decision-making process.

Joe Acaba, leader of NASA’s astronaut office, further emphasized that the pair are test pilots who willingly and intentionally take on risk.

“This mission is a test flight and, as Butch and Suni expressed ahead of their launch, they knew this mission might not be perfect. Human spaceflight is inherently risky and as astronauts we accept that as part of the job,” Acaba said.

Spacecraft are often named after iconic maritime vessels: Williams dubbed Starliner as “Calypso” in honor of Jacques Cousteau’s research ship, which in turn was named for the mythological Greek nymph.

For now, Boeing’s spacecraft shares an unfortunate similarity to its namesake — a critically damaged vessel with an indefinite timeline for repairs — as well as an eerie likeness to its namesake’s namesake — who trapped the hero Odysseus for seven years against his will.