Another New Starliner Landing Date, Updated Spacewalk Plans

Butch Wilmore and Suni Williams are getting another four days on the International Space Station. Their return to Earth and the end of Boeing’s Starliner Crew Flight Test has been reset for June 26 as Boeing and NASA continue to perform spacecraft tests that can only be done on-orbit. NASA also has rearranged the ISS spacewalk schedule after scrubbing a planned outing at the last minute a few days ago.

Boeing’s Starliner capsule Calypso docked at the ISS on June 6.  The first opportunity for them to return was June 14, but that was extended to June 18, then June 22, and now June 26. The relative positions of the ISS and the primary landing sites in New Mexico dictate a four-day spacing for when they can land.

During a media telecon today, NASA Commercial Crew Program Manager Steve Stich stressed that the reason for delaying the return is so NASA and Boeing can learn as much as possible about the spacecraft’s performance while it’s in space. A lot can be done with simulations on the ground, but nothing beats real-life testing in the microgravity environment of low Earth orbit.

Starliner’s Crew Flight Test (CFT) has experienced a number of anomalies since launch on June 5. During the one-day trip to the ISS, five of the 28 Reaction Control Thrusters went offline and more helium leaks occurred. One helium leak was noticed before launch and was part of the reason for a several-week delay, but three more were detected on the way to ISS and another after docking, a total of five.

Stich and Boeing Vice President and Program Manager for Commercial Crew Mark Nappi said today three of the five leaks appear similar. The other two are smaller. They don’t understand the cause of the leaks or why software “deselected” the thrusters. Four of the five thrusters are back online, but one displayed unusual behavior and won’t be used again.

The thrusters and the manifolds where the helium is leaking are in Starliner’s Service Module, which detaches from the Crew Module and burns up during reentry. Since it doesn’t come back to Earth, whatever they can learn has to be done while it’s in orbit.

On Saturday, they briefly fired seven of the eight functioning RCS aft-facing thrusters and got “really good chamber pressure,” Stich said. They also measured the helium leak rates and all were “going down.”  They need 7 hours of helium for undocking and deorbit and have at least 70, more than enough margin. All in all, NASA and Boeing are confident Starliner can bring Butch and Suni back home safely.

This Crew Flight Test is just that, a flight test, and problems were expected. It’s a step towards NASA certifying Starliner for operational flights. The plan was to complete certification by the end of this year with the first operational flight, Starliner-1, early next year. Whether or not that’s still feasible is up in the air.

Nappi and Stich stressed they have a lot of work to do to go through all the data and make whatever changes are necessary. The goal is to “get all the quirks out,” Stich said. Nappi insisted they “fully plan to eliminate” what he called “these nuisances,” and the longer they can stay in orbit the more data they can acquire to that end.

Under the current plan Starliner CFT will undock from the ISS at 10:10 pm ET June 25 and land at 4:10 am ET on June 26.

Like Russia’s Soyuz, Starliner lands on land, not in the ocean like SpaceX’s Crew Dragon or NASA’s Orion. The two primary landing sites are at the White Sands Missile Range in New Mexico, with backup sites at Willcox, Arizona, Dugway Proving Ground, Utah, and Edwards Air Force Base, California. If the June 26 date slips, Stich said the next opportunity would be July 2 and they would land at Willcox. (The date apparently was a misstatement since four days would be June 30.)

Starliner descends under parachutes with airbags deploying just before landing to soften the impact. Two Starliner test flights without anyone aboard took place in December 2019 and May 2022.

Separately, NASA has reconfigured a series of spacewalks at the ISS. The first of three was scrubbed last week when one of the two astronauts experienced “spacesuit discomfort.” Until today NASA declined to identify whether it was Tracy Dyson, a veteran of three spacewalks on previous spaceflights, or Matt Dominick, a rookie on his first flight.

NASA ISS Program Manager Dana Weigel confirmed today it was Dominick’s spacesuit that was causing the problem. She declined to specify what it was, but it couldn’t be rectified in a timely manner and they didn’t want to begin the spacewalk, or extravehicular activity (EVA), and then have to terminate it early when the astronauts were mid-way through a task.

The other two EVAs already were scheduled for June 24 and July 2. NASA is keeping those dates and there will be only those two, not three, because of oxygen supply issues. Even though Dyson and Dominick never left the airlock, they used a lot of oxygen during the pre-breathe period.

On June 24, Dyson and Mike Barratt will go outside and perform the tasks that had been scheduled for last week — removing a faulty electronic box and collecting samples of microorganisms near vents from the interior of the ISS to determine what can survive the harsh space environment. Weigel said Barratt was assigned to that spacewalk because a spacesuit is already configured for him.

She didn’t say who will perform the July 2 EVA, but they’ll remove and replace a gyroscope assembly, relocate an antenna, and prepare for future upgrades to the Alpha Magnetic Spectrometer particle physics experiment.

 

This article has been updated.