CAPE CANAVERAL, Fla. – Boeing’s Starliner spacecraft is ready for its long-awaited first crewed launch.
That launch, which will begin the Crew Flight Test (CFT) mission to the International Space Station (ISS), is scheduled for 12:25 p.m. EDT (1625 GMT) on Saturday (June 1) from the Cape Canaveral Space Force Station here , atop a United Launch Alliance (ULA) Atlas V rocket.
NASA, Boeing and ULA officials provided updates on the launch during a press call on Friday (May 31), confirming that all systems are “go” for Saturday’s launch with NASA astronauts Butch Wilmore and Suni Williams on board . The mission aims to advance Starliner’s certification to transport crew members on operational missions to the ISS.
Leading up to this first shakedown passenger flight, Starliner has suffered a series of delays, both in recent years and in recent weeks. A May 6 attempt was canceled about two hours before takeoff, for example due to a faulty valve in the Atlas V’s Centaur upper stage. That prompted mission managers to roll Starliner and the rocket back to ULA’s vertical integration facility (VIF), where engineers discovered a helium leak in Starliner’s service module.
Related: Boeing Starliner’s first astronaut launch: live updates
Given the location and system interactions within Starliner, it “would have been almost unsafe to work on the leak,” NASA Commercial Crew Program Manager Steve Stich said on Friday’s call. But members of the launch team concluded that the leak was small enough not to pose a serious risk to the spacecraft or to the CFT mission, and the Atlas V/Starliner stack was rolled back to the launch pad on Thursday (May 30).
“Sometimes for spaceflight you plan for contingencies, and you design the vehicle with margin. And in our case, we have margin in the helium tank,” Stich said. “We can handle a leak a hundred times worse than this. So… we decided the smartest thing to do was to fly the mission, and then we could fly it safely.”
Adding to the pre-launch drama, a recent anomaly aboard the ISS caused a last-minute manifest change ahead of tomorrow’s launch: a faulty pump in the station’s urine processor has halted the ability to collect urine from the ISS -crew back into drinkable water. A replacement for this part was already scheduled for launch on Northrop Grumman Cygnus’ next cargo mission in August, but the pump’s unexpected failure necessitated an accelerated delivery, NASA officials announced Friday.
“We are in a position where we have to store urine on board the station,” Dana Weigel, NASA’s ISS program manager, said during Friday’s press conference. “We have bags and tanks there for this purpose, but we have a limited supply.”
With the impending arrival of two new astronauts to the station – Wilmore and Williams at CFT – NASA made the decision to get the needed part into orbit as quickly as possible. But a small sacrifice had to be made.
To maintain consistent mass for Starliner’s mission, it was necessary to remove cargo that was approximately the same weight as the replacement part (approximately 64 kilograms). In this case, Wilmore and Williams’ luggage was hit, leaving the pair without spare clothes once they reached the space station. Fortunately, they won’t change completely without clothes.
“We have a lot of general emergency clothing on board, so that’s not a problem,” Weigel said.
Wilmore and Williams are expected to spend eight days aboard the space station, conducting system checks and generally putting Starliner through its paces. Starliner and its two-person crew are expected to land at Willcox Playa, east of Tucson, Arizona, no earlier than Monday, June 10.
The docking from the ISS will take place around 5:50 a.m. EDT (950 GMT) that morning, with landing at approximately 10:16 a.m. EDT (1416 GMT). If weather issues or other delays occur, a backup landing option will be available at White Sands Missile Range in New Mexico on June 11, with a landing time that day around 6:35 a.m. EDT (1035 GMT).
CFT will kick off tomorrow (June 1) at 12:25 PM EDT (1625 GMT), with a predicted 90% chance of favorable weather. NASA’s livestream starts at 8:15 a.m. (1215 GMT), which you can watch here on Space.com. Coverage will continue during Starliner’s rendezvous and docking with the ISS, scheduled for around 1:50 PM EDT (1750 GMT) on Sunday (June 2).