by Boeing’s Starliner capsule is doing so well on its first-ever astronaut mission that it will likely be able to stay in orbit beyond the originally planned 45-day limit, NASA says.
Starliner, which launched on June 5, has been docked at the International Space Station (ISS) for an indefinite mission extension. The spacecraft is in good shape and rated to leave the ISS in an emergency. But both NASA and Boeing are trying to understand why some of the Starliner’s reaction control system (RCS) launchers had problems during their approach to the ISS on June 6, and why some helium leaks turned up. in the cavity. So, Starliner will remain in space until at least later this summer as tests and analyzes continue. For example, a new round of thruster tests will begin on the ground soon, possibly as early as today (July 2).
Tests on June 15 in orbit were unable to find the root cause of the issues, although agency officials stressed on Friday (June 28) that progress has been made: the helium leaks have been stabilized, and all of the thrusters error only rated for use to come back to Earth. (Starliner has a total of 28 thrusters in its RCS; five were misbehaving, and of those five, only one will be taken offline during undocking.)
Since the RCS is in the Starliner service module, which will launch before entry, descent and landing, the extra time in orbit will allow the crews to take their time to understand how to proceed. This will be critical to any service module design changes required for future six-month ISS rotation missions operated by Starliner as early as 2025. But to give ground crews time for testing, NASA says it must Starliner remained docked for more than 45 days, which was the initial outer limit for this mission. The good news is that the spacecraft looks good enough to go maybe twice that amount of time – or more.
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“We talked about a 45-day limit, limited by the crew module batteries on Starliner, and we’re in the process of updating that limit,” Steve Stich, manager of NASA’s Commercial Crew Program, told reporters during the teleconference Friday.
“We’ve been looking at those batteries and their performance in orbit. They’re being recharged at stations, and that risk hasn’t changed much. So the risk for the next 45 days is basically the the same as the first 45 days,” he said.
In fact, Starliner is rated to stay as long as 210 days in orbit when operational missions begin, he said. But, because this is only Starliner’s third mission in space, and its first with astronauts, NASA was unsure about the battery’s performance in previous orbits.
When asked by Space.com how long the mission could continue, Stich said, “We haven’t decided how long to extend it yet.” Starliner has 12 different batteries, he explained. Before this flight, similar batteries sat on the ground for a year and were then tested to make sure there were no defects, and none were found.
“What we’re really doing is looking at the performance of the battery in flight. We don’t see any degradation in any of the cells that make up the batteries,” he said.
The current Starliner mission, called Crew Flight Test (CFT), was originally supposed to last about 10 days. It features two NASA astronauts: Butch Wilmore and Suni Williams. Both are former US Navy test pilots and have years of experience working in development missions such as this space flight.
Wilmore told Space.com on May 1 that, before launch, the Navy gave the astronauts skills very relevant to CFT, such as testing how systems work together. “Well, my goodness, that’s why we’re here really,” he said, reflecting on the duo’s thousands of hours of piloting experience. Later, he said their experience was “valuable to the process” while working on Starliner.
CFT was meant to examine the unexpected in space, and flexibility in scheduling is part of it. The additional ground test will be conducted at the White Sands Test Facility in New Mexico to try to duplicate how the RCS thrusters were used during flight and especially during docking. (NASA canceled the first docking attempt on June 6 but authorized the second a few hours later.)
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Meanwhile, Williams and Wilmore are supporting the ISS astronauts on other tasks as they await the results of the White Sands test, which will be at least two weeks away. Recent NASA blog posts have detailed the CFT astronauts’ work on ISS maintenance: orbital plumbing for a few days, then more recently organizing items in the Permanent Multipurpose Module.
Williams and Wilmore also worked in the Japan Experiment Module on Monday (July 1) “to dismantle the empty CubeSat NanoRacks Deployment in preparation for upcoming NanoRacks missions,” NASA officials wrote Monday (July 1.)
Starliner’s first two space missions were unmanned. The first, in December 2019, failed to reach the ISS due to computer glitches that left it in the wrong orbit. The second one, in May 2022, arrived safely at the ISS after Boeing made numerous fixes, but the Starliner thrusters had a few problems; That’s another reason NASA and Boeing are taking their time with CFT’s return, to see why the spacecraft misbehaved in both 2022 and 2024.
Boeing is one of two suppliers of ISS astronaut missions, the other being SpaceX. Elon Musk’s company uses its Crew Dragon capsule, which is based on SpaceX’s Dragon cargo vehicle. Crew Dragon has had a faster path to orbit: one uncrewed mission in 2019, followed by an astronaut flight test in 2020. Dragon has sent 11 crews to the ISS since then, most of them on rotational missions six month operational crew for NASA.
