NASA administrator Michael Griffin takes the biggest risk of his career. But it’s a necessary risk, and a good one.

NASA officials decided a crack in Discovery’s fuel tank insulating foam wasn’t enough of a threat to stop the countdown Tuesday to their first Independence Day shuttle launch. The launch is set for 2:38 p.m. EDT.

Inspectors spotted the crack Monday. A 3-inch piece of foam also popped out of the area, which covers an expandable bracket holding a liquid oxygen feed line against the huge external fuel tank.

After several hours of inspections and meetings, officials decided to continue with the launch as planned. NASA administrator Michael Griffin said Tuesday that the crack wasn’t a major concern and that cameras were trained on the area so if ice built up after the super-cold fuel was added, the launch could be delayed.

We establish days, weeks, months in advance the criteria that we have to meet in order to be able to launch. If we don’t meet them, we stand down,” meaning the shuttle doesn’t launch, Griffin told NBC’s “Today” show.

If the weather cooperates, we’ll be back in space–where the future is.

Update: Picture perfect. Happy Independence Day!