Tag: Starliner

It wasn’t perfect, but the propulsion system that NASA worried about did its job today as Boeing’s Starliner space capsule made an uncrewed descent from the International Space Station back down to Earth.

The gumdrop-shaped spacecraft, christened Calypso, floated down to a parachute-assisted, airbag-cushioned touchdown at White Sands Space Harbor in New Mexico. “Starliner is back on Earth,” Boeing commentator Lauren Brennecke said.

Starliner’s first crewed trip to the space station was supposed to last only about a week, but when the capsule made its approach for docking on June 6, five thrusters out of a set of 28 malfunctioned. Four of the thrusters were reactivated, and NASA astronauts Butch Wilmore and Sunita Williams executed a successful docking. But concerns about the thrusters — and about a string of helium leaks in the propulsion pressurization system — sparked weeks of troubleshooting by NASA and Boeing.

Engineers decided that they could cope with the helium leaks, but the thruster problem was a bigger concern. Tests determined that the propulsion system’s performance was degraded by overheating that exceeded design specifications.

Two weeks ago, NASA said the uncertainties surrounding the system’s performance were too great to risk having Williams and Wilmore ride back to Earth on Starliner. Instead, the astronauts were told to remain on the station for months longer than originally planned.

To accommodate the personnel shift, NASA reduced the size of the next scheduled crew, known as Crew-9, from four to two spacefliers. That crew is due to go into orbit in a SpaceX Crew Dragon capsule on Sept. 24. Williams and Wilmore will join Crew-9 and return to Earth in the SpaceX capsule next February.

NASA has decided it’s too risky to have Boeing’s Starliner spacecraft return to Earth from the International Space Station with its two crew members, and so those astronauts will extend their stay by several months and come back on a SpaceX Dragon capsule instead. Starliner, which has been in the midst of its first crewed flight after years of delay, will be reprogrammed to make an uncrewed departure from the space station next month.

Top mission managers said today that they decided unanimously to make a dramatic change in what was originally expected to be a test flight lasting only a couple of weeks. They said there was too much uncertainty surrounding the thruster problems that cropped up during Starliner’s trip to the space station in early June.

“All of us really wanted to complete the test flight with crew, and I think unanimously we’re disappointed not to be able to do that,” said Ken Bowersox, NASA’s associate administrator for space operations.

NASA Administrator Bill Nelson said Boeing “worked hard” to address questions about the thruster system, but in the end, the space agency took what it considered to be the safer course. He said NASA learned its lessons from “mistakes done in the past,” including safety lapses that led to space shuttle disasters in 1986 and 2003.

“Our core value is safety, and it is our North Star,” Nelson said.

Boeing’s Starliner capsule and its two-person NASA crew arrived at the International Space Station today after mission managers coped with some post-launch glitches involving the spacecraft’s propulsion system.

“Today’s docking, I think, was challenging,” Steve Stich, program manager for NASA’s Commercial Crew Program, told reporters after Starliner’s arrival. “We had a few things we had to work through as a team.”

One of the glitches had to do with the thrusters that are used to maneuver the gumdrop-shaped capsule in orbit. Five of the 28 thrusters initially malfunctioned — which forced NASA astronauts Butch Wilmore and Sunita Williams to put their final approach to the station on hold for more than an hour.

Four of the balky thrusters were successfully reactivated, clearing the way for the docking procedure to resume.

Update for May 22: Mission managers say they are evaluating plans for the first crewed flight test of Boeing’s Starliner space taxi and are working toward a launch opportunity on June 1.

An initial attempt to send the gumdrop-shaped capsule and two NASA astronauts to the International Space Station had to be scrubbed on May 6 due to concerns about a fluttery pressure regulation valve on the Atlas V rocket’s upper-stage oxygen tank.

Starliner and the rocket were rolled back to the Vertical Integration Facility at Cape Canaveral Space Force Station’s Launch Complex 41 in Florida. The valve was replaced on May 11 and passed a round of tests — but along the way, engineers detected a small helium leak that was traced to a flange on one of the Starliner service module’s thrusters.

The launch teams at Boeing and NASA determined that the leak was stable. Now they are working on a follow-on assessment of the propulsion system to understand the potential impacts of the helium system on some of the return scenarios for Starliner. That assessment will be evaluated during a flight test readiness review that hasn’t yet been scheduled.

The earliest opportunity for a second launch attempt is now 12:25 p.m. ET (9:25 a.m. PT) on June 1, with additional opportunities on June 2, 5 and 6. The launch teams had previously targeted May 21 and May 25 for liftoff.

The first crewed flight of Boeing’s Starliner space taxi was postponed today due to concerns about a valve on the upper stage of United Launch Alliance’s Atlas V rocket. It was the latest in a years-long string of delays for what’s expected to be a milestone mission for Boeing and commercial spaceflight.

Liftoff had been set for 10:34 p.m. ET (7:34 p.m. PT) today from Cape Canaveral Space Force Station’s Space Launch Complex 41 in Florida. But launch managers called a hold with a little more than 2 hours left in the countdown, after NASA astronauts Butch Wilmore and Sunita Williams had already climbed into the capsule.

“The team has had some observations on an oxygen relief valve on our Centaur second stage, and the team is just not comfortable with the signatures that they’re seeing, the response out of that valve,” United Launch Alliance’s Dillon Rice said. “So, out of an abundance of caution, we are not going to continue with our launch operations today.”

The astronauts climbed out of the capsule and headed back to their quarters. Meanwhile, ULA engineers checked into the balky valve, which didn’t stay closed properly during preparations for launch and made a buzzing noise. The ULA team decided to replace the valve, which led mission managers to schedule the next launch attempt for no earlier than May 17.