Boeing’s Starliner ready for Saturday launch to space station, first flight with crew on board

All systems are “ready” for a second attempt Saturday to launch Boeing’s long-delayed Starliner crew spacecraft on a long-awaited test flight to the International Space Station, the capsule’s first with astronauts aboard, NASA managers said on Tuesday. Friday.

“From the point of view of the station, from our crew, from our ground teams, we are ready to fly this mission,” said Dana Weigel, NASA space station program manager. “We are excited to be at the doorstep of this historic mission.”

The Starliner’s liftoff atop a United Launch Alliance Atlas 5 rocket is scheduled for 12:25 p.m. EDT Saturday, about the time the Earth’s rotation brings pad 41 at Cape Canaveral Space Force Station into alignment with orbit. of the station.

ULA engineers are expected to begin fueling the rocket at around 6:30 am. Veteran NASA astronauts Barry “Butch” Wilmore and Sunita Williams, serving as commander and co-pilot respectively, plan to arrive three hours later to await liftoff.

It will take Atlas 5 about 12 minutes to lift Starliner into orbit, beginning a 25-hour rendezvous with the space station. Docking is scheduled for 1:50 pm on Sunday. If all goes well, Wilmore and Williams will undock and return to Earth on June 10, landing that morning in a desert location in Arizona or New Mexico, depending on the weather.

“I’ve talked to them and they have every confidence in our rocket, they have every confidence in our spacecraft, in our operations teams and in our management teams,” said astronaut Mike Fincke, in training to command a Starliner mission next year. year. “They’re definitely ready to go.”

Speaking of being ready to “go,” the Starliner will carry a urine processing pump module that was added at the last minute to replace one that failed on board the station earlier this week. To make room for the 150-pound component, some crew clothing and other personal items were removed from the ship, but generic clothing is stored aboard the laboratory and no problems are expected.

“The two specific suitcases that came out contained Butch and Sonny’s clothes and also some… of their own unique toiletries,” Weigel said. “Of course we have generic shampoos, soaps, etc. on board that they can use just from the generic supplies. The same goes for clothes, and that’s what they’ll do.”

The long-awaited Starliner flight marks a major milestone in NASA’s Commercial Crew Program, which funded the development of SpaceX’s Crew Dragon and Boeing’s Starliner ferries to provide post-shuttle transportation to and from the space station without having to rely on Russia for inflight travel. the Soyuz spacecraft.

From the beginning, NASA wanted spacecraft from different suppliers to guarantee uninterrupted access to the space station, even if problems delayed a spacecraft for an extended period.

SpaceX began transporting astronauts aboard Crew Dragon spacecraft in 2020 and has already transported 50 astronauts, cosmonauts and civilians to orbit in 13 flights. Boeing’s Starliner, on the other hand, has suffered a steady stream of problems that have delayed the first piloted flight by four years, costing the company more than a billion dollars to fix.

Wilmore and Williams were finally cleared for the May 6 release. They were preparing for liftoff when ULA engineers reported problems with a relief valve used to maintain adequate pressure in an oxygen tank inside the rocket’s Centaur upper stage. I’m not comfortable with the valve’s performance, mission managers asked for a scrub.

The Atlas 5 was transported back to ULA’s Vertical Integration Facility, where a replacement valve was installed, tested and cleared for flight. Meanwhile, Boeing engineers were evaluating data collected after the cleanup that indicated a small helium leak in the plumbing used to pressurize the Starliner’s propulsion system.

The leak was eventually traced to plumbing leading to a specific jet of the reaction control system, one of 28 thrusters mounted around the Starliner’s drum-shaped service module. After extensive testing and analysis, mission managers concluded that the spacecraft could fly safely as is without any credible threat to flight safety.

If the leak worsened drastically during flight, the helium collector in question would be isolated, disabling its thrusters. This would prevent a normal re-entry using more powerful thrusters at the end of the mission, but backup plans exist to perform the de-orbit “burn” using two long bursts from unaffected RCS jets.