The first test flight of Boeing’s Starliner crew capsule with astronauts has been delayed from February to April 2023, moving the mission after a busy stretch of crew and cargo missions to the International Space Station, and allowing more time for engineers to address problems discovered on an unpiloted test flight earlier this year, NASA said Thursday.
The Starliner’s Crew Flight Test will be commanded by veteran NASA astronaut Butch Wilmore, and former space stating commander Suni Williams will be his co-pilot. Boeing and NASA are moving forward with the first crewed test flight of the Starliner spacecraft after a successful unpiloted demo mission to the station in May.
In August, NASA and Boeing officials said they aimed to launch the Starliner Crew Flight Test as soon as February. The space agency updated the schedule Thursday, saying that manager are now targeting April 2023 for the test flight. The delay moves the Starliner test flight after crew rotations at the space station with SpaceX’s Dragon spacecraft and Russian Soyuz vehicles in February and March.
While the Starliner’s unpiloted test flight earlier this year achieved its objectives, successfully docking with the space station and returning to Earth for landing, engineers continue to work on solutions to anomalies encountered on the May demo mission, known as Orbital Flight Test-2, or OFT-2.
“The joint team continues to close out the OFT-2 anomalies and partner closely together to identify forward work and ensure all requirements for crewed flight are met,” NASA said in a statement. “NASA and Boeing currently are working on a variety of verification efforts across several critical systems that will be used for Starliner’s crew flight certification.”
Mark Sirangelo, a member of NASA’s Aerospace Safety Advisory Panel, said in a meeting last month that the OFT-2 mission achieved more than 250 flight test objectives during its six-day mission. But it also resulted in a “number of in-flight anomalies” that need to be resolved for the Crew Flight Test, Sirangelo said.
Preparations on the Starliner spacecraft and its United Launch Alliance Atlas 5 rocket are on track for an early 2023 launch of the Crew Flight Test from Cape Canaveral Space Force Station, Florida, NASA said.
Boeing has two space-rated reusable Starliner crew modules. The one assigned to the Crew Flight Test is named “Calypso” and flew on Boeing’s first unpiloted orbital demonstration mission in December 2019, a test flight that was cut short by software problems before it could dock at the station. The capsule successfully returned to Earth for landing in New Mexico.
The Starliner Calypso spacecraft will be connected to its power and propulsion section, or service module, later this year at Boeing’s Starliner factory at Kennedy Space Center in Florida. Each Starliner mission will use a new service module, which is jettisoned to burn up in the atmosphere at the end of every flight.
The other Starliner crew module flew on the OFT-2 mission in May, and is being refurbished for Boeing’s first operational crew rotation mission to the space station after the Crew Flight Test.
Mark Nappi, Boeing’s Starliner program manager, said in August that engineers identified four areas for “minimal” changes on the Crew Flight Test spacecraft after lessons learned from the OCT-2 mission
One of those areas involves the spacecraft’s Orbital Maneuvering and Attitude Control thrusters. Two of the 20 OMAC engines on the OFT-2 mission shut down early during the spacecraft’s orbit insertion burn just after launch. The other engines compensated for the problem without any significant impacts to the rest of the flight.
Nappi said investigators determined debris in the propulsion system likely caused the problem with the OMAC engines. Technicians have inspected the spacecraft for the Crew Flight Test to make sure its propulsion system is free of any similar particles.
Several smaller Reaction Control System, or RCS, thrusters also stopped working during the Starliner spacecraft’s rendezvous with the station. Nappi said the most likely cause of that problem involved “low inlet pressures and some manifold pressure dynamics that delayed the sensor responses.”
That issue can be resolved by introducing a “very small change” to tweak timing and tolerance settings in the propulsion system, Nappi said in August.
Boeing is also removing some unnecessary filters from cooling loops on the spacecraft’s thermal control system after high pump pressures were detected during the OFT-2 mission.
The Starliner spacecraft’s Vision-based, Electro-Optical Sensor Tracking Assembly, or VESTA, rendezvous sensors performed well during the capsule’s final approach to the space station. The VESTA sensors feed position and closure rate data to the Starliner’s flight computer to autonomously guide the spacecraft in for docking.
But the rendezvous navigation system generated more data than expected during the OFT-2 docking sequence. Boeing is updating the Starliner’s flight software load to accommodate the increased data feeding into the flight computer during the rendezvous with the space station.
NASA said Thursday that qualification testing of the Starliner spacecraft’s flight software that will be used for the Crew Flight Test was completed last. Wilmore, Williams, and backup spacecraft test pilot Mike Fincke recently completed a crew validation test, where the astronauts put on their Boeing spacesuits and climbed into seats on the Starliner spacecraft to ensure a good fit and to check out environmental control and in-cabin audio systems.
Wilmore and Williams will live and work on the space station for about two weeks on the Crew Flight Test mission, NASA said Thursday.
“Following a successful crewed flight, NASA will work to complete certification of the Starliner spacecraft and systems for regular crew rotation missions to the space station,” NASA said. “A launch date for NASA’s Boeing Starliner-1 mission will be determined following a successful flight test with astronauts and close out of the agency’s certification work.”
Boeing is on contract with NASA for six operational crew rotation missions to the International Space Station using the Starliner fleet. The multibillion-dollar commercial crew contract is similar to NASA’s deal with SpaceX for astronaut transportation to and from the space station.
SpaceX completed its crew test flight on a Dragon spacecraft in 2020, and has now launched five operational crew rotation missions to the station, plus two fully commercial private astronaut missions on Dragon capsules.
NASA funded development of the SpaceX and Boeing crew capsules to provide U.S. transportation for astronauts between Earth and the International Space Station. NASA astronauts could only ride Russian Soyuz spaceships to and from the station after the retirement of the space shuttle in 2011.
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