Following the rollback of Discovery's STS-133 stack to the Vehicle Assembly Building at NASA's Kennedy Space Center Wednesday, Dec. 22, engineers immediately began the work to continue evaluation of the intertank area of the External Tank. Since the rollback data analysis from a tanking test has continued to be reviewed along with “non-destructive evaluation” (X-rays) of stringers that were not accessible at the launch pad.
The X-rays showed four additional small cracks on three stringers on the opposite side of the tank from Discovery, and managers elected to repair those cracks in a similar fashion to repairs made on cracks discovered after the Nov. 5 launch attempt. That work is estimated to take 2–3 days. Any further work will be evaluated thoroughly early next week after additional data is reviewed. The hardware is in place to perform any modification. That work would be performed inside the VAB.
Managers continue to evaluate an option to perform known and practiced modifications on additional stringers. A decision may be made as early as Monday, Jan. 3.
The next available launch date is Thursday, Feb. 3 at the opening of a window that extends through Feb. 10. The current preferred launch time on Feb. 3 is 1:37 a.m. EST.