NASA, Boeing Continue to Work Toward Understanding Starliner Service Module Valve Performance Issue

Boeing Starliner spacecraft
On July 29, 2021, Boeing’s CST-100 Starliner spacecraft is shown on top of the United Launch Alliance (ULA) Atlas V rocket in ULA’s Vertical Integration Facility.

NASA continues to work side-by-side with Boeing to understanding the CST-100 Starliner’s service module valve performance, including the unexpected indications some of the valves were in the closed position during its Aug. 3 launch attempt of Orbital Flight Test-2 (OFT-2).

With troubleshooting ongoing in the United Launch Alliance Vertical Integration Facility at NASA’s Kennedy Space Center in Florida, where Starliner will be powered and run through various procedures to help understand the issue, NASA will move forward with the launch and berthing of an important cargo mission to the International Space Station.

Northrop Grumman’s Cygnus spacecraft is scheduled to launch on the company’s Antares rocket at 5:56 p.m. Tuesday, Aug. 10, from NASA’s Wallops Flight Facility in Wallops Island, Virginia, with capture and berthing scheduled two days later at about 6:10 a.m. EDT Thursday, Aug. 12.

In parallel, managers and engineers with NASA and Boeing will continue to evaluate schedules based on where the troubleshooting efforts take them before deciding when the next official launch for the OFT-2 mission will take place.

NASA, Boeing Continue Starliner Data Analysis

Atlas V rocket with Starliner on launch pad
A United Launch Alliance Atlas V rocket with Boeing’s CST-100 Starliner spacecraft onboard is seen on the launch pad on Thursday, July 29, 2021, at Space Launch Complex 41 in preparation for the Orbital Flight Test-2 (OFT-2) mission at Cape Canaveral Space Force Station in Florida. Photo Credit: (NASA/Aubrey Gemignani)

NASA and Boeing are continuing to work through steps to determine what caused the unexpected valve position indications on the CST-100 Starliner propulsion system.

The United Launch Alliance Atlas V with the Starliner spacecraft on top will be returned to its Vertical Integration Facility (VIF) at Launch Complex-41 on Cape Canaveral Space Force Station Thursday where engineers will have direct access to Starliner for continued troubleshooting.

The data will drive any corrective measures that may be necessary to ensure Starliner is ready for launch. When NASA’s Commercial Crew Program and Boeing Space agree the issue is resolved, a new launch opportunity will be selected, taking into account the readiness of all parties involved.

“The Boeing and NASA teams are working methodically to understand what caused the valve indications on the Starliner service module propulsion system,” Steve Stich, manager of the Commercial Crew Program, said. “The troubleshooting in the Vertical Integration Facility will help focus on potential causes and next steps before we fly the OFT-2 mission.”

Early in the launch countdown for the Tuesday, Aug. 3 launch attempt, engineers detected indications that not all of Starliner’s propulsion system valves were in the proper configuration needed for launch of the company’s second uncrewed orbital flight test to the International Space Station, a mission designed to test the end-to-end capabilities of the crew-capable system as part of NASA’s Commercial Crew Program.

Mission teams decided to halt the countdown to further analyze the issue, which was conducted later Tuesday via several steps to troubleshoot the incorrect valve indications, including cycling the service module propulsion system valves.

After presenting the data to NASA and Boeing managers, it was decided to relocate the Atlas V and Starliner to the VIF for further inspection and testing where access to the spacecraft is available. Engineering teams have ruled out a number of potential causes, including software, and the direct access is required to continue the assessment.

“This mission is extremely important for the Commercial Crew Program on the path to the Boeing Crewed Flight Test,” Stich said. “We will fly the mission when we are ready. I am extremely proud of the NASA and Boeing teams for their professionalism, perseverance, and methodical approach to solving complex problems.”

NASA and Boeing will take whatever time is necessary to ensure Starliner is ready for its important uncrewed flight test to the space station and will look for the next available opportunity after resolution of the issue.

NASA, Boeing Standing Down on Aug. 4 Starliner Launch Attempt

NASA and Boeing are standing down from the Wednesday, Aug. 4, launch attempt of the agency’s Orbital Flight Test-2 to the International Space Station as mission teams continue to examine the cause of the unexpected valve position indications on the CST-100 Starliner propulsion system.

Early in the launch countdown for the Aug. 3 attempt, mission teams detected indications that not all valves were in the proper configuration needed for launch. Mission teams decided to halt the countdown to further analyze the issue.

NASA and Boeing worked through several steps to troubleshoot the incorrect valve indications, including cycling the service module propulsion system valves, within the current configuration of the Starliner and United Launch Alliance Atlas V rocket at Space Launch Complex-41 on Cape Canaveral Space Force Station in Florida.

Mission teams have decided to roll the Atlas V and Starliner back to the Vertical Integration Facility (VIF) for further inspection and testing where access to the spacecraft is available. Boeing will power down the Starliner spacecraft this evening. The move to the VIF is expected to take place as early as tomorrow.

Engineering teams have ruled out a number of potential causes, including software, but additional time is needed to complete the assessment.

NASA and Boeing will take whatever time is necessary to ensure Starliner is ready for its important uncrewed flight test to the space station and will look for the next available opportunity after resolution of the issue.