NASA grounded Discovery Nov. 5, after finding tiny cracks on the fuel tank’s support beams. The extremely cold temperatures of the liquid fuels do cause the metal beams to contract and move.
But engineers did not expect them to
Repair work to space shuttle Discovery's external fuel tank begins in the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. Technicians will modify 32 support beams, called stringers, on the tank's intertank region by fitting pieces of metal, called radius blocks, over the stringers' edges where they attach to the thrust panel area.
“This was a tough problem.”
John Shannon is the shuttle program manager. He says engineers found problems with how the tank was assembled and with the metal itself.
It was weaker than expected, leading to the cracks.
Shannon says engineers can fix the weak spots by installing little strips of metal onto the top part of every beam. There are 108 beams encircling the fuel tank.
“We’re going to fly with a lot of confidence in this tank. I think through doing a tanking test and the x-rays and building our factor of safety up with this very simple modification. We’ve gotten rid of the uncertainty in the discussion and we’re gonna fly with a lot of confidence.”
NASA officials refused to answer any questions about astronaut Mark Kelley. He is the husband of Congresswoman Gabrielle Giffords, who was shot in the head Saturday in Tuscon.
Kelley is supposed to command the Endeavor shuttle flight in April. Bill Gerstenmeier is a NASA administrator.
“We really are not ready to answer those questions today. We’re going to let Mark decide really kind of what he needs to do. And I’ll think we’ll do that out of respect for Mark and what he’s dealing with. And our hearts and prayers go out to the family and we’re really thinking about Mark in everything we do.”
Space Shuttle Discovery is now set to launch Feb. 24 at the earliest.