The return to Earth of Boeing’s Starliner capsule is on indefinite hold pending outcomes of recent thruster checks and ongoing evaluation of helium leaks that cropped up through the ship’s rendezvous with the International Space Station, NASA introduced Friday.
But company officers insisted Starliner commander Barry “Butch” Wilmore and co-pilot Sunita Williams are not “stranded” in area.
NASA
“We don’t have a targeted (landing) date today,” Steve Stich, NASA’s Commercial Crew Program supervisor, informed reporters throughout a teleconference. “We’re not going to target a specific date until we get that testing completed.
“So essentially, it’s complete the testing, complete the fault tree, bring that analysis into (the mission management team), and then have an agency-level review. And then we’ll lay out the rest of the plan from undock to landing. I think we’re on a good path.”
The problem for NASA and Boeing is that the Starliner’s service module, which homes the helium traces, thrusters and different vital techniques, is discarded earlier than re-entry and burns up within the environment.
Engineers will not have the ability to research the {hardware} after the very fact, and consequently, they wish to gather as a lot knowledge as doable earlier than Wilmore and Williams head dwelling.
But the crew’s repeatedly prolonged keep on the area station as that evaluation has continued has prompted some observers to say Wilmore and Williams are stranded in orbit, an impression that appears to have taken root within the absence of updates from NASA because the goal landing date was repeatedly pushed again.
Stich and Mark Nappi, Boeing’s Starliner program supervisor, mentioned that description is a mischaracterization.
“It’s pretty painful to read the things that are out there,” Nappi mentioned. “We’ve gotten a really good test flight…and it’s being viewed rather negatively. We’re not stuck on ISS. The crew is not in any danger, and there’s no increased risk when we decide to bring Suni and Butch back to Earth.”
Stich added that he desires “to make it very clear that Butch and Suni are not stranded in space. Our plan is to continue to return them on Starliner and return them home at the right time. We’ll have a little bit more work to do to get there for the final return, but they’re safe on space station. Their spacecraft is working well, and they’re enjoying their time on the space station.”
The Starliner was launched June 5 on this system’s first piloted check flight with one already recognized helium leak. The different 4 developed through the ship’s rendezvous with the area station when the jets had been quickly pulsed to advantageous tune the Starliner’s method.
United Launch Alliance
While docked on the station, valves are closed to isolate the helium system, eliminating any extra leakage. But as soon as Wilmore and Williams depart and head for dwelling, the valves will probably be re-opened to repressurize the traces, or manifolds.
Stich mentioned that even with the recognized leaks, the spacecraft could have 10 occasions the quantity of helium it must get dwelling, however engineers wish to be certain the leaks will not worsen as soon as the system is once more pressurized.
The 5 aft-facing thrusters within the Starliner’s service module additionally didn’t function as anticipated throughout method to the area station on June 6.
After docking, 4 of the 5 jets had been efficiently check fired and regardless of barely decrease energy ranges than anticipated, they’re thought of good to go for undocking and re-entry. The fifth thruster was not “hot fired” as a result of it is earlier efficiency indicated it had truly failed.
But managers wish to discover out what precipitated the surprising habits within the different 4. Starting subsequent week, a brand new thruster similar to those aboard the Starliner will probably be check fired at a authorities facility at White Sands, New Mexico, precisely just like the these in orbit had been fired through the Starliner’s rendezvous and docking.
“We’ll recreate that profile,” Stich mentioned. “Then we’ll put a pretty aggressive profile in the thruster for (the undocking-to-re-entry) phase.”
NASA
It’s doable the glitches with the aft-facing thrusters had been attributable to higher-than-normal temperatures as a result of Starliner’s orientation with respect to the solar, or the sequence of speedy, repetitive firings commanded by the flight software program. Or each.
The floor checks, anticipated to final “a couple of weeks,” could present proof somehow.
“This will be a real opportunity to examine a thruster just like we’ve had in space on the ground, a detailed inspection,” Stich mentioned. “Once that testing is done, then we’ll look at the plan for landing.”
As for the impression the crew is stranded in area, Stich and Nappi each identified that on Wednesday, a defunct Russian satellite tv for pc in a barely decrease, extra tilted orbit than the area station suffered a catastrophic “event” that produced greater than 100 items of trackable particles.
While flight controllers evaluated the trajectories of the wreckage, the area station’s nine-member crew was informed to “shelter in place” aboard their respective spacecraft, prepared to right away depart and return to Earth in case of a harmful affect.
Two Russian cosmonauts and NASA’s Tracy Dyson boarded their Soyuz ferry ship, whereas three NASA astronauts and one other cosmonaut floated into their SpaceX Crew Dragon. Wilmore and Williams rode out secure haven contained in the Starliner and had been cleared to fly dwelling if warranted.
After about one hour, the crew was given the all clear to return to regular work. Had the Starliner had been thought of unsafe, Wilmore and Williams probably would have been informed to hunt refuge within the Crew Dragon. But that was not the case.
“We have an approval to be a lifeboat in case of an emergency on ISS,” Nappi mentioned. “That means we can return with the Starliner at any time, and that was proven this week.”