Discovery, awaiting its 39th and final flight, greets the dawn at NASA's Kennedy Space Center. Photo Credit/NASA
Shuttle Discovery’s long-delayed final mission to the International Space Station moved a step closer to a late February launching, as managers completed a program level flight readiness review on Friday.
The session cleared the way for a Feb. 18 executive level NASA Flight Readiness Review at the Kennedy Space Center to establish a formal launch date.
In the meantime, the 11-day flight is tentatively set to lift off on Feb. 24 at 4:50 p.m., EST.
The mission will be the 39th and final flight for NASA’s fleet leading orbiter.
A crew of six astronauts has trained to deliver and equip the orbiting science laboratory with an equipment storage module and an external platform for the stowage of spare parts.
Discovery’s payload includes Robonaut 2, an experimental humanoid developed to work alongside astronauts outside as well as inside the station.
The mission has been on hold since a Nov. 5 launch scrub in response to a launch pad hydrogen leak.
Subsequently, technicians found a long unrelated crack in the insulating foam that covers Discovery’s external fuel tank.
Further investigation revealed small cracks in the underlying stringer section of the external tank. With further troubleshooting, engineers attributed the cracks to the use of an unusually crack prone aluminum-lithium alloy in the stinger section, the forces resident in the assembly of the tank as well as the cold temperatures associated with the flow of liquid hydrogen and oxygen propellants into the fuel tank on Nov. 5.
The cracked stingers have since been repaired and equipped with structural doublers. In addition, other stringers were equipped with a “radius block” to fortify them against the stresses of the cold propellant and the forces of the climb to orbit.
Commander Steve Lindsey leads a crew that includes pilot Eric Boe and mission specialists Mike Barrett, Nicole Stott, Alvin Drew and Steve Bowen.
During the delay, veteran astronaut Tim Kopra was removed from the flight, when he suffered a hip injury in a bicycle accident.
Bowen took Kopra’s place and will join Drew for a pair of maintenance spacewalks out side the station.