(CNN) -- NASA crews will begin a test of space shuttle Discovery's external fuel tank Friday.
The test at the Kennedy Space Center in Florida will give engineers key data to decide when the shuttle can take off, NASA said.
The earliest possible launch date is February 3, according to the agency.
Cracks found in the foam covering the fuel tank have repeatedly delayed the shuttle's final launch, originally scheduled for November 1.
Technicians repaired the cracks and reapplied foam insulation on aluminum brackets on the tank last month.
Earlier this month Space Shuttle Program manger John Shannon told reporters that workers would outfit the cracked tank with sensors and fill it with cryogenic fuel, then watch to see what happens in an effort to understand the glitch.
The foam cracked while the tank was being filled November 5 for the shuttle's planned launch to the International Space Station.
Discovery is scheduled to deliver a storage module, a science rig and spare parts to the orbiting facility.
The delay means the final launch of Endeavour, which is also scheduled to be the last launch of the Space Shuttle Program, will likely be delayed until April 1, Bill Gerstenmaier, associate administrator for space operations, told reporters.