After a week in which the final launch of space shuttle Discovery has been postponed on an almost daily basis, NASA has announced that it won't be taking off until at least the end of the month.
It's now set for launch at 4:05 am EST on November 30 - assuming nothing else goes wrong.
The delay will give engineers and technicians time to diagnose and repair a hydrogen gas leak which was found on Friday morning while filling the external tank. They also need to check out a foam crack on the external fuel tank's liquid oxygen intertank flange.
"We always place safety first," said NASA associate administrator for Space Operations Bill Gerstenmaier. "It is essential we repair this hardware before we fly the mission, and we will take the time to properly understand and fix the failure before we launch."
The crew for the 11-day mission will be headed by commander Steve Lindsey, with the other astronauts named as pilot Eric Boe and mission specialists Alvin Drew, Tim Kopra, Michael Barratt and Nicole Stott.
The STS-133 mission will deliver the Permanent Multipurpose Module - converted from the multi-purpose logistics module Leonardo -to the International Space Station.
The PMM will host microgravity experiments in areas such as fluid physics, materials science, biology, and biotechnology. Inside is Robonaut 2, which will stay permanently on the station and will be used to evaluate how dexterous robots behave in space.
STS-133 also is carrying vital spare parts for the space station and the Express Logistics Carrier 4, an external platform that holds large equipment. The mission will feature two spacewalks to do maintenance work and install new components.