Wednesday, July 13, 2005
Shuttle Discovery Launch Delayed
Today's scheduled return to flight for the space shuttle Discovery (STS-114, scheduled for 3:51 PM ET) has been scrubbed. Though weather was becoming a concern, they had to scrub the mission because at least 2 of the low-fuel sensors on at least one of the three shuttle engines was malfunctioning. Each engine has 4 of these sensors, and all must be working for the mission to be a go.
Depending on how easy it is to fix the sensor problem, Discovery MAY be able to launch tomorrow, sometime in the 3-4 PM ET time frame. If it can't launch tomorrow, Saturday will be the next opportunity, and after that, Tuesday. They can't launch on Friday because if the mission can't go off tomorrow, the fuel in the shuttle will have had a chance of degradation and will need to be replaced. This would happen on Friday if Discovery doesn't launch Thursday. You can follow the coverage of the return to flight over the next few days by going to either NASA's main site or to the Return to Flight page.
CNN is reporting that it was only 1 sensor in a set of 4 on one engine that was faulty. Either way, it was about 2 hours and 45 minutes before launch, and, without knowing exactly why the sensor was malfunctioning (and if it was/is a problem that might occur to the other sensors, too), they didn't want to risk it. MSNBC is currently reporting that if the sensor itself is faulty, then the shuttle will have to be rolled back into the Vehicle Assembly Building (VAB). If that happens, the next attempt won't be until 9 September (due to the relative position of ISS and the launch window to be able to dock with it). More details as they become available.
(Image directly from http://www.nasa.gov/images/content/118270main1_114_crew_port_330.jpg)