NASA, Boeing set new undocking, landing date for Starliner spacecraft

This view from a window on the cupola overlooks a portion of the International Space and shows the partially obscured Starliner spacecraft from Boeing docked to the Harmony module’s forward port. Image: NASA

NASA and Boeing teams pushed back the target undocking and landing date for the Starliner spacecraft from the International Space Station by four days. They shifted from June 18 to now no earlier than June 22.

The reason for the extended stay is in part due to a need to gather more information about the Starliner capsule with the benefit of having an astronaut crew assigned to study aspects of the spacecraft with additional detail.

“The crew can do more detailed testing into the various aspects of the spacecraft hardware with the additional time in orbit. It’s an opportunity that is important because the spacecraft is new and this is the first time carrying a crew that can perform this testing on-orbit,” a NASA spokesperson told Spaceflight Now. “Even though an effort is repeated, the additional work gives them a chance to refine what they saw the first time and pass more knowledge to the crews of Starliner missions to come.”

Some of the work that will be done in the next several days will also be to better understand some of the anomalies that Starliner experienced during its journey to the orbiting outpost and while docked.

A total of five helium leaks were identified over the course of the mission so far, beginning with the one characterized following the May 6 launch scrub. Ground teams are also studying a reaction control system (RCS) thruster oxidizer isolation valve in Starliner’s service module “that is not properly closed.”

During the rendezvous process, some thrusters that were acting out of character were taken offline temporarily by the spacecraft’s software. One of the five thrusters that was misbehaving was left offline for docking.

Steve Stich, NASA’s Commercial Crew Program manager, characterized the issue during a post-docking news briefing.

“These thrusters are similar to what we saw in OFT-2. We don’t quite understand why they’re happening. We took a couple of actions in the software to mitigate potential fail-offs by the [guidance, navigation and control] part of the software,” Stich said on June 6. “Again, we recovered the thrusters and they were working just fine during the rendezvous except for one that we left inhibited. These are not at all related to the helium leak. The helium leak is separate, they’re in different doghouses, it’s different thrusters. So, the helium leak and the thrusters are not at all related.”

In a statement on Friday, NASA said flight controllers planned to “fire seven of its eight aft-facing thrusters while docked to the station to evaluate thruster performance for the remainder of the mission.” There will be two burns during the hot fire test, each lasting about a second.

There are also new crew activities being added to the schedule for NASA astronauts Butch Wilmore and Suni Williams, who docked Starliner to the ISS on June 6, a day after their launch atop a United Launch Alliance Atlas 5 rocket.

“We are continuing to understand the capabilities of Starliner to prepare for the long-term goal of having it perform a six-month docked mission at the space station,” Stich said in NASA’s June 14 blog post. “The crew will perform additional hatch operations to better understand its handling, repeat some ‘safe haven’ testing and assess piloting using the forward window.”

Since arriving, they’ve also performed a number of tasks directly related to their Crew Flight Test mission, but have also lent their talents to station upkeep, assisting with spacewalk activities and performing some scientific research.

Suni Williams supports the Genes in Space Molecular Operations and Sequencing, or GiSMOS, experiment on June 12. Image: NASA

ISS mission managers intentionally kept the station schedule fairly open to allow for maneuvering room when it came to the timing of launch and docking as well as for the duration of the spacecraft attached to the station.

NASA and Boeing team leaders will provide additional details on the progress of the test flight during a press briefing at 12 p.m. EDT (1600 UTC) on Tuesday, June 18. The primary and backup landing sites for Starliner in the southwestern United States are still being determined.

“We have an incredible opportunity to spend more time at station and perform more tests which provides invaluable data unique to our position,” said Mark Nappi, Boeing’s vice president and program manager of its Commercial Crew Program division. “As the integrated NASA and Boeing teams have said each step of the way, we have plenty of margin and time on station to maximize the opportunity for all partners to learn – including our crew.”