The next attempt to launch the Space Shuttle with ESA astronaut Roberto Vittori and the Alpha Magnetic Spectrometer will not be made until Sunday at the earliest. Friday’s first attempt was scrubbed because of a technical problem.
Engineers at NASA's Kennedy Space Center in Florida have identified the likely cause behind the failure of heaters on a fuel line for Shuttle Endeavour's auxiliary power unit on Friday.
There appears to be a power problem within Aft Load Control Assembly-2, a box of switches controlling power feeds.
"That basically means the power is not getting out to the heaters that weren't working on launch day," said Space Shuttle Program Launch Integration Manager Mike Moses.
The plan is to remove and replace the box, but that work and related testing will take several days to complete. Once the new box is installed, the team must verify it is working properly and study the failed box, taking at least two days.
"We're really not even setting the schedules today. There's still a whole lot of short-term work that has to be done," said Moses, indicating that the launch will be no earlier than 8 May.
The launch window will remain open after that until 26 May.
Astronauts waiting in Houston
The six STS-134 astronauts returned on Friday to NASA's Johnson Space Center in Houston for a few days of refresher training before they return for the next launch attempt.
"Responding to problems is one of the things we do best around here, and the team always likes a good challenge," said Shuttle Launch Director Mike Leinbach.
"I am sure we are going to be really glad when Endeavour's finally on orbit, but right now, the team is upbeat and ready to execute."