NASA is willing to fly another crewed flight on Boeing's Strainer after the ship's previous mission to the International Space Station (ISS) created sufficient uncertainty about its propulsion system to make NASA managers fly the ship back to Earth without a crew on board. Starliner's first crewed flight test, CFT-1, saw astronauts Butch Wilmore and Suni Williams fly to the ISS last year and return earlier this month after spending nine months in space. In a press release issued earlier today, the space agency outlined that it is working to resolve the ship's anomalies and certify it for crewed missions as it works towards its next flight.
NASA & Boeing Will Test Starliner's Propulsion System Through Spring And Summer Before Next Test Flight
In its release, NASA outlines that it is continuing to test Starliner's propulsion system to solve the anomalies that it exhibited during Starliner CFT last year. The ship's thrusters failed to fire as it tried to dock to the ISS in June, forcing pilot Butch Wilmore to hold the ship in position and in proximity to the space station as ground teams resolved the problem.
While the ship successfully docked, Boeing and NASA teams continued to test its thrusters on Earth to determine the root cause. Their investigations initially led them to believe that deformed Teflon seals might have caused the problems. However, when teams tested the ship's thrusters in space, they performed nominally and cast doubt on whether the Teflon seals were the root cause, as they are unlikely to have reverted to their original state after being deformed.
The uncertainty, coupled with the complex schedule of flights that needed an open port on the ISS, forced NASA to bring the ship back to Earth uncrewed, with Williams and Wilmore booked for their return trip on SpaceX's Crew Dragon instead.
Now, NASA shares that it plans to certify Starliner for crewed flights and resolve its in-flight anomalies as part of preparations for another mission. The space agency outlines that it and Boeing have analyzed 70% of the data from the ship's crewed mission. It adds that the "major in-flight propulsion system anomalies Starliner experienced in orbit are expected to remain open further into 2025." According to NASA, these anomalies will remain open until ground test campaigns and upgrades to the ship are complete.
Some of the tests that NASA and Boeing will run include firing thrusters in a single service module to evaluate upgrades to the ship's propulsion system. These tests will allow the space agency to determine the date of Starliner's next test flight, according to NASA's Commercial Crew Program (CCP) manager Steve Stich. The CCP is built on redundancy through which NASA prefers to have two dissimilar spacecraft available to ensure continued access to the ISS.
Crucially, NASA also reveals that "managers are planning for the next Starliner flight to be a crew capable post-certification mission." This implies that future crewed flights of the ship are not off the table; however, the agency adds that it does have the option to conduct cargo-only flights as well.