Engineers filled the fuel tank of the space shuttle Discovery Friday in tests to help pinpoint the cause of defects that have delayed its launch, dpa reported.
NASA has encountered numerous delays over the last month in trying to get Discovery off the ground for its farewell voyage before the shuttle fleet is retired. The mission was scheduled for liftoff in late October before several cracks found on brackets on the external tank prompted multiple delays.
As part of tests to find the cause of the problem, engineers filled the tank with fuel while monitoring it for strains or cracks.
An initial survey of the tank found no cracks had occurred during the test, but NASA said it would take several weeks to analyze its findings.
NASA is also conducting a separate test that involves building a mockup of that part of the fuel tank to see if engineers can reproduce the cracks to determine a root cause.
The ageing space shuttle fleet is set to be retired after nearly three decades in service. Some of the shuttle's tasks are to be shifted to commercial space flight providers, while NASA is to develop a spacecraft that can travel to more distant destinations.
Though the shuttle spacecraft themselves are reused after each flight, the external liquid fuel tank is new for each flight, meaning the age of the fleet is unrelated to the current problem.
Discovery is now set for launch no earlier than February 3.