For the second time in a month, the first crewed launch of Boeing’s Starliner space capsule to the International Space Station was called off while the crew members were in their seats, waiting for liftoff.
The hold was automatically triggered by the launch-pad computer system that manages the final minutes of the countdown for Starliner’s launch vehicle, an Atlas V rocket provided by United Launch Alliance.
The ground launch sequencer forced an end to today’s launch attempt at Cape Canaveral Space Force Station in Florida with just three minutes and 50 seconds remaining in the countdown. Mission managers started investigating what triggered the alarm even as the launch pad team began the process of helping NASA astronauts Butch Wilmore and Sunita Williams out of the capsule.
United Launch Alliance CEO Tory Bruno said the automated launch sequencer triggered an alarm because a circuit card on one of three redundant computer racks came up about six seconds more slowly than the other two. That particular card controls activities that free up the rocket for liftoff.
“For that system, we do require all three systems to be running. … Two came up normally. The third one came up, but it was slow to come up,” Bruno said at a news briefing. “That tripped a red line that created an automatic hold.”
The NASA-ULA-Boeing team said it would pass up a launch opportunity on June 2 to give engineers more time to assess the situation. The computer problem could be due to faulty hardware, which would be relatively simple to swap out, or it could be a more complex issue involving network connections between the computers.
