Starliner launch scrubbed due to valve issue
Yesterday’s Starliner launch was scrubbed before launch because ULA had detected an issue with a valve on the Atlas-5’s Centaur upper stage, causing that valve to flutter because it had not closed in the proper position.
At the press conference that followed, ULA’s CEO Tory Bruno explained that during an unmanned launch, engineers would have simply cycled the valve, which almost always works to get it to seat properly. ULA launch rules however forbids it from doing so on a manned launch, because that would be the equivalent of fueling the tank with people on board the rocket. The Atlas-5 was initially not built for manned flights, and though it has been upgraded to man-rate it, those upgrades did not permit ULA this capability, unlike SpaceX’s Falcon 9, which get fueled entirely after the crew boards Dragon.
They are reviewing the data to see if the valve will need to be replaced. If not, the launch could happen quickly. If it does, the launch will be delayed slightly longer, but not significantly. Right now ULA, NASA, and Boeing are targeting a May 10th launch.
It is worth listening to Tory Bruno’s explanation of the situation because of its clarity. I have embedded his comments below, time-stamped to when he began speaking.
» Read more
Yesterday’s Starliner launch was scrubbed before launch because ULA had detected an issue with a valve on the Atlas-5’s Centaur upper stage, causing that valve to flutter because it had not closed in the proper position.
At the press conference that followed, ULA’s CEO Tory Bruno explained that during an unmanned launch, engineers would have simply cycled the valve, which almost always works to get it to seat properly. ULA launch rules however forbids it from doing so on a manned launch, because that would be the equivalent of fueling the tank with people on board the rocket. The Atlas-5 was initially not built for manned flights, and though it has been upgraded to man-rate it, those upgrades did not permit ULA this capability, unlike SpaceX’s Falcon 9, which get fueled entirely after the crew boards Dragon.
They are reviewing the data to see if the valve will need to be replaced. If not, the launch could happen quickly. If it does, the launch will be delayed slightly longer, but not significantly. Right now ULA, NASA, and Boeing are targeting a May 10th launch.
It is worth listening to Tory Bruno’s explanation of the situation because of its clarity. I have embedded his comments below, time-stamped to when he began speaking.
» Read more