The saga of Boeing’s Starliner continues. The spacecraft, intended to ferry astronauts between Earth and the International Space Station (ISS), is currently performing its first crewed test flight, but what was supposed to be a one-week test has turned into a multiweek debacle.
Though the two astronauts who traveled on the Starliner, NASA’s Butch Wilmore and Suni Williams, are in no danger, they have been stuck on the ISS for seven weeks now. NASA insists that they are not stranded and that they could use the Starliner to travel back to Earth in the case of an emergency, but concerns about the performance of the Starliner mean they still have no planned return date.
In a press conference today, July 25, NASA shared details about the testing being performed on the Starliner’s thrusters, some of which malfunctioned during the ISS docking process seven weeks ago.
At the NASA facility in White Sands in New Mexico, engineers are testing a thruster from a Starliner that had been intended for use on a future mission to try to recreate the conditions that caused the original thrusters to fail. The problem seems to stem from the pulse rate — that is, how frequently it was fired successively in a short time (rather than how hard it was fired or how many pulses overall) A similar problem of loss of thrust was seen in the tester thruster as well.
“Right now we’re in the middle of the teardown of the thruster,” said Steve Stich, NASA Commercial Crew Program manager. “So, we have the thruster at the White Sands test facility, it’s in the lab, it’s been disassembled. And we’re looking very carefully at the fuel valve and the oxidizer valve.” These two valves control the flow of propellant into the thruster, and one of them is showing a bulge in a seal, which could be responsible for the issues.
The important issue is whether the seal, and therefore the thruster, could survive the return flight to Earth. Current testing suggests that it can, but NASA was set to perform more testing to check this. The next major piece of testing is a hot fire test, in which 27 of the Starliner’s thrusters will be fired while in orbit to check if any failures occur. That test is scheduled for this weekend.
In addition to the thruster issue, the spacecraft was also leaking helium on its journey to the station. Since it has been docked, the manifolds have been closed so the system doesn’t leak, but now each manifold will be pressurized to test whether the leaks reoccur.
Another concern was the Starliner’s batteries, which were originally only cleared for 45 days in space. The Starliner has now passed that limit, but the safe life of the batteries has been extended to 90 days.
While testing of any spacecraft will often turn up issues, and Williams and Wilmore have been positive about their experiences with the Starliner, the ongoing issues with the Starliner and the lack of quick resolution is starting to wear on the patience of the space community, with questions raised about whether NASA’s communications during this time have been sufficient.
“There’s been a ton of learning over the last couple of months while we’ve been docked that really is preparing us for increment operations,” said Stich. There is still no date set for the return, however.
