NASA and Boeing Delay Starliner Return Again Again Again

NASA has announced that it has postponed the return of the CST-100 Starliner spacecraft from the International Space Station (ISS) until at least early July. This decision comes as both NASA and Boeing continue to investigate propulsion system problems.

The delay disrupts previously outlined plans for Starliner to depart the ISS on June 25 and land at White Sands, New Mexico early on June 26, completing the Crew Flight Test (CFT) mission with NASA astronauts Butch Wilmore and Suni Williams on board.

Unlike previous delays, NASA did not specify a new departure date. Instead, the agency is “evaluating future return opportunities” for the spacecraft following a scheduled spacewalk on July 2, the second of a pair planned at the ISS.

“We are taking our time and following our standard mission management team process...We are letting the data drive our decision making relative to managing the small helium system leaks and thruster performance we observed during rendezvous and docking.” - Steve Stich, NASA's Commercial Crew Program Manager.

NASA plans to conduct an agency-level review of Starliner before its departure “given the duration of the mission.” Originally scheduled for an eight-day stay at the ISS, the latest delay means Starliner will spend close to a month there.

At a June 18 briefing, Stich and other officials expressed confidence in a June 26 return. They noted that testing had confirmed that all but one reaction control system thruster was functioning well and that helium leaks had diminished during the thruster tests.

“We really like the opportunity on the 26th because it’s a great opportunity into the White Sands Space Harbor,” - Steve Stich, NASA's Commercial Crew Program Manager.

The additional time on station will be used for more data collection and to manage the two planned spacewalks.

“We are strategically using the extra time to clear a path for some critical station activities while completing readiness for Butch and Suni’s return on Starliner and gaining valuable insight into the system upgrades we will want to make for post-certification missions.” - Steve Stich, NASA's Commercial Crew Program Manager.

However, NASA officials had previously scheduled the spacewalks to avoid conflicts with Starliner’s potential departure dates. Dana Weigel, NASA ISS program manager, stated at the June 18 briefing that if the first spacewalk, scheduled for June 24, was delayed, Starliner’s planned June 25 undocking would take precedence. “We’ll make sure we work around the Starliner schedule.”

During the same briefing, officials stressed that they were not driven by schedule.

“We have an opportunity to extend a little bit, and that really is an opportunity,” - Mark Nappi, Boeing Vice President and Commercial Crew Program Manager.

The original eight-day stay was a minimum that could be extended to gather more data, given that the service module containing the propulsion system does not return to Earth.

“This is an opportunity to fully understand the system’s performance without the pressure of schedule or time. We have the time...We’ll let the data drive our decision-making.” - Mark Nappi, Boeing Vice President and Commercial Crew Program Manager.

NASA's statement did not indicate how long Starliner could remain at the station, only that the crew “is not pressed for time to leave the station since there are plenty of supplies in orbit” and no other missions are scheduled for the ISS through mid-August.

While NASA did not provide a specific date for the next return opportunity, Mike Lammers, a NASA flight director supporting the CFT mission, mentioned at the June 18 briefing that landing opportunities follow a “every four day” pattern based on the ISS’s orbit and the location of landing sites in the southwestern United States. This suggests the next possible landing date after the spacewalks would be around July 4.

Despite the delay, NASA emphasized that Starliner could return Wilmore and Williams in an emergency.

“So far, we don’t see any scenario where Starliner is not going to be able to bring Butch and Suni home...We’re just taking a little more extra time to resolve the data and also learn as much as we can while we have the service module in orbit.” - Steve Stich, NASA's Commercial Crew Program Manager.