CAPE CANAVERAL, Fla. — Boeing’s Starliner spacecraft is ready for its long-awaited first manned launch.
That liftoff, which will begin a Crew Flight Test (CFT) mission to the International Space Station (ISS), is scheduled for 12:25 p.m. EDT (1625 GMT) Saturday (June 1) from Cape Canaveral Space Force Station here, on top United Launch Alliance (ULA) Atlas V rockets.
Officials from NASA, Boeing and ULA provided an update on the launch during a press conference on Friday (May 31), confirming that all systems are ready for Saturday’s launch with NASA astronauts Butch Wilmore and Suni Williams. The mission aims to deepen Starliner’s certification for crew transport in operational missions to the ISS.
Ahead of this first shakedown passenger flight, the Starliner has faced a series of delays, both over the past few years and in the past few weeks. The May 6 attempt was cleared about two hours before liftoff, for example, due to a faulty valve in the upper stage of the Atlas V Centaur. That prompted mission managers to return the Starliner and the rocket back to ULA’s Vertical Integration Facility (VIF), where engineers discovered a helium leak in the Starliner’s service module.
Related: First Boeing Starliner Astronaut Launch: Live Updates
Given the location and interactions of the systems inside the Starliner, it would be “almost unsafe to work” on the leak, NASA Commercial Crew Program Manager Steve Stich said during the briefing Friday. But launch team members concluded the leak was small enough not to pose a serious risk to the spacecraft or the CFT mission, so the Atlas V/Starliner package was returned to the launch pad on Thursday (May 30).
“Sometimes in spaceflight you plan for contingencies and design the vehicle to have a backup. And in our case, we have a backup in the helium tank,” Stich said. “We could deal with a leak 100 times worse than this. Well…we decided it was wisest to go fly the mission, and we could fly safely.”
Adding to the pre-launch drama, a recent anomaly on the ISS created a manifest last-minute change ahead of tomorrow’s liftoff: A malfunctioning pump in the station’s urine processor stopped the ISS crew’s ability to convert urine back into drinking water. A replacement for this part was already planned for launch on the next Northrop Grumman Cygnus cargo mission in August, but an unexpected pump failure required an expedited delivery, NASA officials announced Friday.
“We are in a position where we have to store urine on the station,” Dana Weigel, NASA’s ISS program manager, said during a press conference on Friday. “We have bags and containers that we have up there for this purpose, but we have a limited inventory.”
With the imminent arrival of two new astronauts to the station – Wilmore and Williams on the CFT – NASA made the decision to send the required part into orbit as soon as possible. But a small sacrifice had to be made.
To maintain consistent mass for the Starliner mission, a payload roughly equal in weight to the replacement part—about 140 pounds (64 kilograms)—had to be removed. In this case, Wilmore and Williams’ luggage took a hit, leaving the pair without spare clothes once they reach the space station. Fortunately, it won’t be complete without a change of clothes.
“We have a lot of generic contingency clothing. So that’s not a problem,” Weigel said.
Wilmore and Williams are scheduled to spend eight days on the space station, performing system checks and generally putting the Starliner through its paces. The Starliner and its two-man crew are expected to land no later than Monday, June 10, at Willcox Playa, east of Tucson, Arizona.
Departure from the ISS that morning will be around 5:50 AM EDT (950 GMT) and landing around 10:16 AM EDT (1416 GMT). If weather issues or other delays arise, there is an opportunity for a backup landing on June 11 at White Sands Missile Range in New Mexico, with a landing time that day around 6:35 a.m. EDT (1035 GMT).
The CFT is scheduled to lift off tomorrow (June 1) at 12:25 EDT (1625 GMT), with a forecast 90% chance of favorable weather. NASA’s live broadcast begins at 8:15 a.m. (12:15 GMT) and you can watch it here on Space.com. Coverage will continue through Starliner’s rendezvous and docking with the ISS, scheduled for around 1:50 p.m. EDT (1750 GMT) on Sunday (June 2).