Boeing finished loading hydrazine and nitrogen tetroxide maneuvering propellants over the weekend into the company’s second space-rated Starliner capsule at the Kennedy Space Center, days after stacking of its Atlas 5 launcher began a few miles away at Cape Canaveral Space Force Station.
The capsule is scheduled to launch July 30 at 2:53 p.m. EDT (1853 GMT) on a test flight to the space station. If all goes according to plan, it will clear the way for Boeing to carry astronauts to the station, possibly before the end of this year.
That will be welcome news to NASA, which has funded the Starliner spacecraft’s development through its a commercial crew program in a cost-sharing arrangement with Boeing. NASA’s commercial crew contracts with Boeing since 2010 are valued at more than $5 billion.
NASA has a similar set of contracts with SpaceX valued at more than $3 billion for development of the Crew Dragon spacecraft. The contracts for both companies included a minimum of six operational crew rotation flights to the International Space Station.
Boeing appeared on track to launch its first Starliner crew mission in 2020, but the Starliner’s first unpiloted test flight in December 2019 ended prematurely without docking with the space station. Boeing and NASA officials blamed the botched test flight on software issues, including a mission elapsed timer clock that was incorrectly set before launch.
The problem caused the spacecraft’s computer to think it was in a different flight phase after deployment from the Atlas 5 rocket in orbit, causing the to capsule fire thrusters and burn too much propellant. The higher-than-expected fuel usage prevented the Starliner spacecraft from docking with the space station.
Ground teams uncovered another software coding error that could have caused the spacecraft’s service module to collide with the crew module after the two elements separated just before re-entry. During certain parts of the shortened two-day mission, there were also difficulties establishing a stable communications link between the Starliner spacecraft and NASA’s network of tracking and data relay satellites.
Despite the problems, the capsule returned to Earth for a parachute-assisted, airbag-cushioned landing at White Sands Space Harbor, New Mexico.
Boeing is now refurbishing that capsule for the Starliner Crew Flight Test. But first, Boeing and NASA managers agreed to launch a second Orbital Flight Test, a mission called OFT-2, to wring out the spacecraft’s software and complete the demonstration tasks left unaccomplished by the OFT-1 mission in 2019.
A second Starliner crew module will fly on the OFT-2 mission. Once it is back on Earth, Boeing will refurbish the capsule for future crew missions. Every Starliner mission will feature a new service module, which burns up during re-entry.
But the OFT-2 mission has to well before Boeing and NASA can finalize a schedule for the Crew Flight Test.
Boeing said last week that engineers have closed out all recommendations from a joint NASA-Boeing independent review team set up to investigate the problems on the OFT-1 mission. The review team issued 80 recommendations, including more thorough integrated software testing and mission simulations, process improvements, crew module communication system improvements, and organizational changes.
“Boeing has implemented all recommendations, even those that were not mandatory, ahead of Starliner’s upcoming flight,” the company said in a statement.
Earlier this year, Boeing completed an end-to-end mission simulation in the company’s Avionics and Software Integration Lab in Houston. The test combined flight hardware and the final version of the spacecraft’s flight software.
The end-to-end rehearsal was not performed to verify software code before the OFT-1 mission in 2019.
If the OFT-2 mission achieves all its objectives, Boeing and NASA officials will “look for opportunities toward the end of the year” to launch the Starliner Crew Flight Test. That mission, which also launch on an Atlas 5 rocket, will carry NASA astronauts Barry “Butch” Wilmore, Mike Fincke, and Nicole Mann to the International Space Station.
The Atlas 5 first stage and Centaur upper stage for the Crew Flight Test arrived Sunday at Port Canaveral after riding ULA’s transport ship from a factory in Decatur, Alabama.
Ground crews unloaded the rocket stages from the vessel Monday to begin launch processing at Cape Canaveral Space Force Station.
The OFT-2 mission will use the Atlas 5 rocket originally assigned to the Crew Flight Test.
If the piloted demonstration flight goes well, NASA will clear Boeing for the first of its six operational crew rotation missions to the space station in 2022.
Email the author.
Follow Stephen Clark on Twitter: @StephenClark1.