ULA has completed repairs to Atlas V‘s ground launch sequencer, which was the cause of Saturday’s last-minute abort to Boeing‘s first crewed liftoff. Starliner’s CFT mission has been rescheduled for Wednesday, June 5 at 10:52 A.M. ET.
Saturday’s launch attempt ended with a scrub at the T-3:50 mark. While it took some time for teams to figure out what caused the abort, as it was done automatically by the launch sequencer, it was determined to be a slower than expected computer.
Tory Bruno, ULA CEO, explained the scrub in a post-launch press conference Saturday afternoon. In a bunker adjacent to the rocket, there are three computers that run the ground launch sequencer. This automatically controls parts like valves, umbilicals, and other ground equipment in the final moments before launch.
The unplanned hold to the count just after the T-4 minute planned hold was because one of the three computers were running slower than the others. At this point in the count, all three computers are expected to be operational and a slower computer was against flight rules, holding the count and scrubbing the launch attempt.
Bruno stated Saturday afternoon that teams would have to manually inspect the computer hardware to determine how extensive the delay would be. Swapping out computer components could be quick, but if it was something more extensive like the power supply, a Sunday launch attempt would be unlikely.
That’s exactly what caused the slow computer, the power supply. Late Saturday evening, when ULA teams were able to gain access to the computer when detanking operations were complete, NASA announced Wednesday, June 5 would be Starliner‘s next launch day.
Bruno confirmed Sunday that the power supply was in fact the problem, and that the repair was complete.
A month into its first crewed launch campaign and years behind schedule, Starliner and its Atlas V seem to be ready once again to try this launch on Wednesday.
Good news, the leak that was seen after the first launch attempt was seemingly smaller than before, so that doesn’t look to be a concern now.
