Starliner capsule on top of the Atlas V rocket in the VIF
Photo by: Nasa
The US space agency, the National Aeronautics and Space Administration (Nasa), and giant US aerospace and defence group Boeing agreed on Friday that the latter’s CST-100 Starliner capsule had to be removed from the top of its Atlas V launch rocket and returned to a Boeing facility for more thorough examination of malfunctioning valves in the capsule’s propulsion and manoeuvring system. This has required an indefinite postponement of the planned launch.
Boeing is one of the two companies that was selected to provide astronaut Earth-to-orbit (and back) transport services under Nasa’s Commercial Crew Programme (CCP). The other was SpaceX. However, while SpaceX’s Crew Dragon is already routinely carrying astronauts to and from the International Space Station, Boeing’s spacecraft, the CST-100 Starliner, has not yet made a fully successful uncrewed test flight.
The Starliner was meant to make its second uncrewed test flight, designated Orbital Flight Test-2, on August 3, from the US Space Force’s Cape Canaveral Space Force Station’s Space Launch Complex-41 (in the US state of Florida). It was integrated on top of an Atlas V rocket on the launch pad and undergoing the launch countdown when the problem with the valves, which are connected with the capsule’s thrusters, emerged.
No fewer than 13 of the valves in the capsule’s propulsion system had failed to open, when commanded to do so, during the launch countdown. Attempts to cure the problem on the launch pad failed, so the Starliner/Atlas V combination was moved back to the United Launch Alliance’s (ULA’s) Vertical Integration Facility (VIF) at the Launch Complex. (ULA manufactures the Atlas V.) In the VIF, Boeing engineers, using commands and electrical, mechanical and thermal techniques, were able to get nine of the valves to open. But the remaining four refused to do so.
This meant that more thorough examination was required, and so the decision was taken to remove the capsule from the top of the Atlas V and to return the Starliner to Boeing’s Commercial Crew and Cargo Processing Facility, which is also in Florida. This means that the Starliner has lost its current launch window.
“Mission success in human spaceflight depends on thousands of factors coming together at the right time,” pointed out Boeing CCP VP and programme manager John Vollmer. “We’ll continue to work the issue from the Starliner factory and have decided to stand down for this launch window to make way for other national priority missions.”
“Although we wanted to see Starliner fly in this [launch] window, it’s critical that our primary focus is the safety of the crew transportation system – for the safety of the space station and the crew members that will be flying on these vehicles,” affirmed Nasa associate administrator: Human Exploration and Operations Mission Directorate Kathryn Lueders. “We’ll only fly this test when we think we are ready, and can complete the mission objectives.”