CNN —
The latest attempt at an inaugural crewed launch of Boeing’s Starliner spacecraft is on track for Wednesday after a
computer issue halted the countdown just moments before liftoff on Saturday.
The historic mission, called the Crew Flight Test, is set to launch at 10:52 a.m. ET from Cape Canaveral Space Force Station in Florida. The event will stream live on
NASA’s website, with coverage beginning at 6:45 a.m. ET.
United Launch Alliance technicians and engineers assessed the ground support equipment over the weekend, examining three large computers housed inside a shelter at the base of the launchpad. Each computer is the same, providing triple redundancy to ensure the safe launch of crewed missions.
“Imagine a large rack that is a big computer where the functions of the computer as a controller are broken up separately into individual cards or printed wire circuit boards,” said Tory Bruno, president and CEO of United Launch Alliance, during a Saturday news conference. “They’re all stand-alone, but together, it’s an integrated controller.”
The cards within the computers are responsible for different key systems that must occur before a launch, such as releasing bolts at the rocket’s base so it can lift off after ignition.
During the final four minutes before launch, all three computers must communicate and agree with one another. But during Saturday’s countdown, a card on one of the computers was six seconds slower in responding than the other two computers, indicating that something was not correct and triggering an automatic hold, according to Bruno.
Over the weekend, engineers evaluated the computers, their power supply and network communications between the computers. The team isolated the issue to a single ground power supply within one of the computers, which provides power to the computer cards responsible for key countdown events — including the replenishment valves for the rocket’s upper stage, according to an
update shared by NASA.
Starliner teams reported no signs of physical damage to the computer, which they removed and replaced with a spare. Meanwhile, mission specialists continue to analyze the faulty power unit to better understand what went wrong.
The other computers and their cards were also assessed, and all of them are performing normally as expected, according to the ULA team.
The Starliner mission management team reviewed the computer replacement troubleshooting steps that were taken, and they have agreed that Starliner is “go” for launch on Wednesday, according to an update from
NASA.
“I really appreciate all the work by the NASA, Boeing, and ULA teams over the last week,” said Steve Stich, manager of NASA’s Commercial Crew Program, in a statement. “In particular, the ULA team worked really hard to quickly learn more about these issues, keep our NASA and Boeing teams informed, and protect for this next attempt. We will continue to take it one step at a time.”
