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The latest attempt at the inaugural launch of the Boeing Starliner crewed spacecraft is on track for Wednesday after a computer problem halted the countdown just moments before Saturday’s launch.
The historic mission, called Crew Flight Test, is scheduled to lift off at 10:52 a.m. ET from the Cape Canaveral Space Force Station in Florida. The event will be streamed live on NASA’s website beginning at 6:45 a.m. ET.
Veteran NASA astronauts Butch Wilmore and Suni Williams will be the first crew to ride aboard the Starliner, propelled into orbit atop an Atlas V rocket built by United Launch Alliance, a joint venture between Boeing and Lockheed Martin.
The much-anticipated flight lasted 3 minutes and 50 seconds after liftoff on Saturday afternoon when an automatic shutdown triggered by the ground launch sequencer, or the computer that fires the rocket, occurred. The teams safely extracted the astronauts from the capsule, and Williams and Wilmore returned to the crew quarters as the rocket ran out of fuel.
Joe Raedle/Getty Images
A Boeing Starliner spacecraft sits atop a United Launch Alliance Atlas V rocket at Cape Canaveral Space Force Station in Florida on May 31.
Over the weekend, United Launch Alliance technicians and engineers assessed ground support equipment and examined three large computers housed in a housing at the base of the launch pad. Each computer is identical and provides triple redundancy to ensure the safe launch of manned missions.
“Imagine a big rack that’s a big computer, where the functions of the computer, like the controller, are separated out into individual cards or circuit boards,” said Tory Bruno, president and CEO of United Launch Alliance, during a press conference Saturday. . “They are all separate, but together they form an integrated controller.”
The cards in the computers are responsible for various key systems that must occur before launch, such as loosening the screws at the base of the rocket so that it can lift off after ignition.
During the last four minutes before the start, all three computers must communicate with each other and agree. But during Saturday’s countdown, the card on one of the computers was responding six seconds slower than the other two computers, which Bruno said signaled something was wrong and triggered an automatic suspension.
Over the weekend, engineers evaluated the computers, their power supply and the network communication between the computers. The team isolated the problem to a single ground power supply within one of the computers that powers the computer cards responsible for key countdown events — including the rocket’s upper stage replenishment valves, according to an update shared by NASA.
The 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 propulsion unit to better understand what went wrong.
Other computers and their cards have also been assessed and according to the ULA team, they are all working normally as expected.
The Starliner mission management team reviewed the computer replacement troubleshooting steps that were taken and agreed that Starliner is “launched” on Wednesday, according to an update from NASA.
“I really appreciate all the work the NASA, Boeing and ULA teams have done over the past week,” said Steve Stich, NASA Commercial Crew Program Manager. “The ULA team worked really hard to quickly learn more about these issues, inform our NASA and Boeing teams, and protect themselves from this next attempt. We will continue to do it step by step.”
The mission teams successfully navigated several additional issues that arose earlier in the countdown to Saturday’s launch attempt. These problems included the loss of data from the ground valves responsible for adding liquid oxygen and hydrogen to the second or upper stage of the Atlas V rocket before launch.
Both the liquid oxygen and hydrogen that are used to fuel the rocket boil off as the rocket sits on the pad before launch, so refueling continues until liftoff. After evaluating the problem, mission teams switched to a redundant valve data system and were able to resume the process.
Weather conditions are 90% favorable for Wednesday morning’s launch, with cumulus clouds the only concern, according to the US Space Force’s 45th Weather Squadron. If the launch does not happen on Wednesday, there is another opportunity on Thursday at 10:29 a.m. ET, according to NASA.
If the Starliner successfully lifts off, the astronauts will spend just over 24 hours traveling to the International Space Station.
Joe Skipper/Reuters
Veteran NASA astronauts Butch Wilmore (left) and Suni Williams are seen before Starliner’s second launch attempt Saturday.
After docking, Williams and Wilmore will spend eight days living in an orbiting laboratory, joining the seven astronauts and cosmonauts already on board. Both will continue to test the functionality of the Starliner spacecraft while it is docked at the space station and then return home aboard the same capsule. It is expected to parachute to one of several designated locations in the southwestern United States.
In the meantime, both astronauts remain in quarantine to protect their health before launch and are practicing procedures and simulations ahead of the historic flight, according to NASA.