An Atlas 5 rocket carrying Boeing's Starliner crew capsule was mounted on its seaside launch stand Wednesday, setting the stage for blastoff Thursday on the company's third attempt to complete an unpiloted test flight to the International Space Station.
Software glitches spoiled the Starliner'sin December 2019, preventing an autonomous rendezvous and docking with the International Space Station, and corroded valves last August.
But Boeing and NASA say they're finally ready for another try, and the United Launch Alliance Atlas 5 was rolled out of its processing facility and mounted atop pad 41 at the Cape Canaveral Space Force Station, clearing the way for takeoff at 6:54 p.m. Thursday. Forecasters predicted a 70% chance of good weather.
If all goes well, the unpiloted Starliner capsule will carry out a 24-hour rendezvous, guiding itself to a docking at the space station's forward port around 7:10 p.m. Friday. On board: about 500 pounds of crew supplies and equipment, along with an instrumented astronaut mannequin dubbed "Rosie the Rocketeer."
Asking about his confidence in Boeing and the Starliner's readiness for flight after a string of frustrating setbacks, astronaut Butch Wilmore, who has been in training to fly aboard a Starliner, said "we wouldn't be here right now if we weren't confident, confident that this would be a successful mission."
"There are always unknown unknowns, that's what historically has always gotten us, right? It's those things that we don't know about and we don't expect," he said. But given the exhaustive testing and analysis that's gone into correcting past problems with the Starliner, he said, "we're ready, the spacecraft is ready, these teams are ready."
The flight plan calls for the capsule to spend five days attached to the lab complex before returning to Earth for a parachute-assisted landing May 25 at White Sands, New Mexico. Assuming no major problems, Boeing and NASA hope to launch an astronaut crew to the station on a piloted test flight before the end of the year.
It's been a long time coming.
In 2014, NASA awarded Boeing a $4.2 billion contract to build the Starliner while SpaceX won a $2.6 billion contract to build Crew Dragon spacecraft. The goal was to re-establish U.S. human space flight capability in the wake of the space shuttle's 2011 retirement, ending NASA's sole reliance on Russia for astronaut ferry flights to the space station.
Like Boeing, SpaceX carried out an unpiloted test flight of its Crew Dragon capsule in 2019 and went on to launch two astronauts to the space station in May 2020. Since then, the company has launched four operational NASA crew rotation flights to the ISS, one commercial visit to the outpost and a privately chartered flight to low-Earth orbit.
Highlighting a blistering launch pace, SpaceX launched a Falcon 9 rocket carrying 53 Starlink internet satellites from nearby pad 39A at the Kennedy Space Center Wednesday morning, a few hours before the Atlas 5 rollout. It was the company's 155th Falcon 9 flight, the 21st so far this year and the fourth this month alone.
SpaceX has helped NASA end its post-shuttle reliance on Russian Soyuz spacecraft for transportation to and from the space station. But agency managers are anxious for Boeing to begin operational crew rotation flights as soon as possible to provide assured access to space in the event problems that might temporarily ground either launch system.
"More is better, we can't have all of our eggs in one basket," veteran astronaut Mike Fincke, who's also trained to fly aboard a Starliner, said in an interview with CBS News.
"Something could go on with SpaceX, they could have a glitch with a Falcon 9, they're launching them all the time, and that could delay us ... getting back and forth to the International Space Station."
Having a second provider, he said, "gives us a robust capability so if one isn't working, we've got the other one."
Steve Stich, manager of NASA's Commercial Crew Program, said the agency's long-term plan is one crew flight per year for Boeing and one for SpaceX.
"The plan is to have the (Starliner) orbit flight test and collect the data from that and review it, then we'll go move into the crewed flight test for Boeing," he said. "Once we do those two flight tests, we'll move into the final certification. And then at that point, we'll assign Starliner to the soonest post-certification mission that we can."
Despite a significantly larger contract and many decades of experience building space hardware, Boeing has had a surprisingly tough time getting the Starliner to the space station.
The capsule's initial test flight in 2019 was marred by software glitches, including one that prevented the spacecraft's flight computer from loading the correct launch time and trouble with radio reception that prevented flight controllers from quickly correcting the problem. Mis-timed thruster firings prevented rendezvous and docking with the space station.
Those problems and others were resolved after the capsule's return to Earth and Boeing geared up for a reflight last August, at its own expense, to put the fixes to the test. But at the last minute, engineers discovered valves in the capsule's propulsion system had jammed due to internal corrosion.
After attempting to troubleshoot at the pad, mission managers were forced to haul the Starliner back to its processing hangar for extensive inspections and analyses to pin down the cause of the corrosion and implement systems to prevent such problems in the future.
As it turned out, unexpected water intrusion in the valves, the presumed result of high humidity and stormy weather at the launch pad, triggered a chemical reaction with propellants that caused corrosion buildups, preventing multiple valves from working as required.
Company engineers are still assessing a possible redesign of the valves, but in the meantime gaseous nitrogen is flowing through the thruster pods to keep them dry, seals have been added to wiring to further isolate the hardware and the valves have been regularly opened and closed to verify performance.
"NASA's sure, Boeing's very confident that we're going to have a successful mission," Fincke told reporters. "If for some reason it wasn't, then we'll have to re-gather and go from there."
"But ... we have a great team that's really gone through this with a fine-tooth comb," Fincke said. "So we're looking forward to a good launch and a good docking to the International Space Station."