Update: Mission managers say they are evaluating plans for the first crewed flight test of Boeing’s Starliner space taxi and are working toward a launch opportunity on June 1.
An initial attempt to send the gumdrop-shaped capsule and two NASA astronauts to the International Space Station had to be scrubbed on May 6 due to concerns about a fluttery pressure regulation valve on the United Launch Alliance Atlas V rocket’s upper-stage oxygen tank.
Starliner and the rocket were rolled back to the Vertical Integration Facility at Cape Canaveral Space Force Station’s Launch Complex 41 in Florida. The valve was replaced on May 11 and passed a round of tests — but along the way, engineers detected a small helium leak that was traced to a flange on one of the Starliner service module’s thrusters.
The launch teams at Boeing and NASA determined that the leak was stable. Now they are working on a follow-on assessment of the propulsion system to understand the potential impacts of the helium system on some of the return scenarios for Starliner. That assessment will be evaluated during a flight test readiness review that hasn’t yet been scheduled.
The earliest opportunity for a second launch attempt is now 12:25 p.m. ET (9:25 a.m. PT) on June 1, with additional opportunities on June 2, 5 and 6. The launch teams had previously targeted May 21 and May 25 for liftoff.
Steve Stich, manager of NASA’s Commercial Crew Program, said in today’s update that it was important for the launch teams to “take our time to understand all the complexities of each issue, including the redundant capabilities of the Starliner propulsion system and any implications to our Interim Human Rating Certification.”
NASA astronauts Butch Wilmore and Suni Williams are continuing their preparations to take Starliner on a weeklong shakedown cruise to the International Space Station and back. “We will launch Butch and Suni on this test mission after the entire community has reviewed the teams’ progress and flight rationale” at the readiness review, Stich said.
If the flight test goes according to plan, Boeing’s Starliner would join SpaceX’s Crew Dragon in the rotation for crew flights to and from the space station.
A series of technical snags has led to years of delays and more than $1 billion in cost overruns for the Starliner program. Under the terms of NASA’s fixed-price contract for Starliner development, Boeing has had to cover the extra expense.
This report, first published May 14, has been updated with the revised launch plan.
