A last-minute problem halted Saturday's launch countdown for Boeing's first astronaut flight. Two NASA astronauts were strapped into the company's Starliner capsule and awaiting liftoff when the countdown was halted at three minutes and 50 seconds. With only a split second to take off Saturday afternoon, there was no time to work the latest trouble and everything was called off. NASA wants a backup to SpaceX, which has been flying astronauts for four years. When space shuttle Challenger exploded in 1986 and Columbia was lost in 2003, fourteen astronauts were killed and the shuttle fleet was grounded for months.
Initial reports were that computer called a Ground Launch Sequencer experienced a problem that prompted mission managers to put the countdown on hold, and eventually scrub the blastoff for the day. The controllers coordinates thousands of systems surrounding the Alabama built Atlas-V and NASA's Starliner capsule itself. The computer saw something it didn't like and called for an abort.
NASA, Boeing, and Alabama rocket builder United Launch Alliance took weeks of review to show that the capsule could safely fly with two test pilots, despite a propulsion system leak. The small helium leak was discovered following the first launch attempt on May 6th that was scuttled by an unrelated rocket problem. Engineers suspect a defective rubber seal the size of a shirt button, and say that even if the leak worsens, it could be managed in flight.
If not for the Atlas V rocket's bad valve that halted the first countdown, Starliner would have launched from Cape Canaveral earlier this month with the leak first detected in orbit, according to NASA Commercial Program Manager Steve Stich. Flight controllers would have managed the leak, and the astronauts would have been safe, officials stressed. Helium is used to pressurize the fuel lines of the propulsion system, which maneuvers the capsule in flight.
Launch scrubs aren’t unusual for NASA. Back in 1993, space shuttle Discovery was poised to carry a crew of astronauts and the Advanced Communication Technology Satellite when the liftoff was cancelled with 1/10 of a second before launch. Computers detected an issue with one of Discovery’s main engines. That shuttle mission was notable because it was the first a Global Positioning Satellite (GPS) receiver was operated in orbit.
For now, Starliner capsule is already years late in transporting astronauts to the International Space Station for NASA. SpaceX has been launching crews since 2020. NASA wants both companies for taxi service so they can back each other up.
