Shuttle Launch Attempt Friday

NASA is readying the shuttle Atlantis for another attempt on Friday morning. They are also negotiating with the Russians for a one day extension if needed (the launch window closes on Friday). They are not replacing a fuel cell that caused the earlier cancellation.

Friday is the last launch day available before the U.S. space agency runs into a scheduling conflict with the Russian space agency, although NASA was negotiating with the Russians about possibly trying on Saturday, if needed.

There was a 30 percent chance bad weather would interfere at the 11:40 a.m. EDT Friday launch time.

On Thursday, NASA decided not to change out an electricity-generating fuel cell whose coolant pump had given erratic readings, causing a scrub a day earlier. Replacing the fuel cell could have delayed any launch attempt by several weeks.

"Our risk really is going to be minimal," said Steve Poulos, shuttle orbiter projects manager. "It was going to be a really sporty event to go in there."

After this weekend, the next daylight launch opportunity is not until the end of October. NASA rules say Atlantis must lift off in daylight so that its big external fuel tank can be photographed for any signs of broken-off foam of the sort that destroyed Columbia 3 1/2 years ago.

If Atlantis does not get off the ground on Friday, NASA officials had two options they were reluctant to exercise that would permit a launch attempt before the end of October: Try on Saturday, or relax the daylight-launch rule.

I understand why they have banned the night launches, but I can tell you from personal experience they are spectacular. My family was in Orlando one year and watched a night launch from there. That is how far away you can see and hear one of these puppies taking off.