NASA on Tuesday said the space shuttle Discovery is now scheduled for lift-off on February 24.

Technicians have discovered what caused the cracks in Discovery's tanks, and have a solution that should be completed by month's end, officials said during a Tuesday press conference. Though complex, the problem was basically two-fold: assembly issues and material that was not strong enough to resist fractures.

"It's been a difficult problem for us because it wasn't easily understood," said Bill Gerstenmaier, associate administrator for Space Operations.

"I am very confident that we've finally got it figured out and we've got a fix that's easy to implement and we'll be 100 percent ready to go later this month," said John Shannon, Space Shuttle Program manager.

Discovery was initially scheduled to take off and head to the International Space Station (ISS) on November 1. Leaks, inclement weather, electrical issues, and cracks, however, have delayed that launch more than a half dozen times. Most recently, it was pushed from December 17 to February 3 and then late February after more cracks were found on Discovery's external tank.

These cracks were discovered on support beams, or stringers. To stregthen, the shuttle program will add radius blocks to the shuttle's stringers, which will provide added structural support to those areas. "These radius blocks essentially fit over existing stringer edges through which the securing rivets are installed to provide additional structural support," NASA said.

Shannon said he was "extremely happy with how this team has approached this problem." In the grand scheme of things, rectifying this problem in two months is pretty impressive, he said.

"We kind of get beat up a little bit because we've had a series of slips... but it's only been two months," he said. "I'm just astounded this team was able to pull it all together and come to this point. It was a great effort. We're going to fly with a lot of confidence in this tank."

The NASA team declined to discuss Commander Scott Kelly, who is currently at the ISS. Kelly is the brother-in-law of Rep. Gabrielle Giffords, the Arizona Democrat who was shot Saturday in a Tucson-area shopping mall.