NASA and Boeing officers are prepared for a second try to launch the primary crew check flight on the Starliner spacecraft Saturday from Cape Canaveral Area Power Station, Florida.
Liftoff of Boeing’s Starliner capsuled atop a United Launch Alliance Atlas V rocket is about for 12:25 pm EDT (16:25 UTC). NASA commander Butch Wilmore and pilot Suni Williams, each veteran astronauts, will take the Starliner spacecraft on its first journey into low-Earth orbit with a crew on board.
The primary crew flight on a brand new spacecraft is not an on a regular basis occasion. Starliner is the sixth orbital-class crew spacecraft within the historical past of the US area program, following Mercury, Gemini, Apollo, the area shuttle, and SpaceX’s Crew Dragon. NASA signed a $4.2 billion contract with Boeing in 2014 to develop Starliner, however the challenge is working years not on time and has price Boeing practically $1.5 billion in price overruns. SpaceX, in the meantime, received a contract concurrently Boeing and began launching astronauts on the Crew Dragon 4 years in the past this week.
Now, it’s lastly Starliner’s flip. A profitable crew check flight would set the stage for six operational Starliner flights to ferry astronauts to and from the Worldwide Area Station (ISS).
Assuming the check flight will get off the bottom Saturday, the spacecraft is due for docking on the ISS at 1:50 pm EDT (17:50 UTC) Sunday to start a keep of a minimum of eight days. As soon as managers are happy the mission has achieved all its deliberate check goals, and pending good climate situations in Starliner’s touchdown zone within the western United States, the spacecraft will depart the station and return to Earth for a parachute-assisted landing. If the mission takes off on Saturday, the earliest nominal touchdown date can be Monday, June 10.
Wilmore and Williams have been right here earlier than. On Might 6, the astronauts have been strapped into their seats inside Starliner’s cockpit awaiting takeoff on a flight to the Worldwide Area Station. A valve malfunction on the Atlas V rocket prevented launch that day, and officers subsequently found a helium leak on Starliner’s service module that delayed the mission till this weekend.
Flying as-is
After weeks of opinions and evaluation, managers decided Starliner is protected to fly as-is with the leak. The spacecraft makes use of helium fuel to pressurize its propulsion system and push hydrazine and nitrogen tetroxide propellants from inside tanks to the capsule’s maneuvering thrusters.
“After we checked out this drawback, it didn’t come all the way down to trades,” stated Mark Nappi, Boeing’s vice chairman and program supervisor for Starliner. “It got here all the way down to: Is it protected or not? And it’s protected, and that’s the reason we decided that we are able to fly with what now we have.”
Floor groups traced the leak to a flange on considered one of 4 doghouse-shaped propulsion pods across the perimeter of the Starliner spacecraft’s service module. In a worst-case state of affairs, if the situation grew worse through the flight, floor controllers may isolate it by closing the manifold feeding the leak. If the leak would not worsen, engineers are assured they will handle it with no main impacts to the mission.
“We seemed actually laborious at what our choices have been with this specific flange,” stated Steve Stich, supervisor of NASA’s industrial crew program, which oversees the company’s contract with Boeing. The flange has a helium conduit and features for the spacecraft’s poisonous gas and oxidizer, which makes a restore “problematic,” Stich stated.
With a view to safely repair the leak, which officers consider is probably going brought on by a faulty seal, floor groups must disconnect the capsule from the Atlas V rocket, take it again to a hangar, drain its propellant tanks. This might in all probability push again the long-delayed Starliner check flight till late this yr.
However the leak is comparatively small and secure. “It’s a couple of half-pound per day trip of fifty kilos of whole functionality within the tank,” Stich stated.
“In our case, now we have margin within the helium tank, and we’ve seemed actually laborious to know that margin and to know the worst instances, and we took the time to undergo that information,” Stich stated. “We actually suppose we are able to handle this leak, each by it earlier than the launch, after which if it bought greater in flight, we may handle it.”
