NASA retargets Atlantis launch for May 11

Launch of the shuttle Atlantis on a mission to upgrade the Hubble Space Telescope has been moved up one day and retargeted for May 11 at 2:01:49 p.m. EDT.

NASA officials said Wednesday that they hoped to push the launch date up in order to increase the odds of a successful launch before a deadline of May 14. But they needed to assess whether such a schedule change was feasible. Engineers and managers concluded Friday that processing could, in fact, be accelerated without affecting required work. Senior managers will hold an executive-level flight readiness review next Thursday to discuss final clearance for launch.

By moving launch up one day, NASA will have three days in which to get Atlantis off the ground before standing down to make way for a military operation on the Air Force Eastern Range, the agency that provides telemetry and tracking support for all rockets launched from Florida.

If the weather or some other problem keeps Atlantis on the ground past May 13, launch will be delayed to May 22 at the earliest because of the range conflict and time needed to recharge the new batteries being delivered to Hubble aboard the shuttle.

A NASA spokesman said the only downside to moving launch up one day was a minor reduction in battery charging time, from 209 hours to 185. But that is still well above the 156-hour requirement for the new batteries, and Hubble Program Manager Preston Burch agreed to move the planned launch.

"Everybody signed off on it," said a NASA spokesman.

As reported earlier this week, NASA is hoping to get Atlantis off as soon as possible to avoid any problems for the next shuttle mission, a space station assembly flight by shuttle Endeavour. Endeavour currently is mounted atop launch pad 39B at the Kennedy Space Center, on standby for launch on an emergency rescue mission if the Atlantis astronauts run into any problems that might prevent a safe re-entry.

Assuming a rescue flight is not needed, Endeavour will be moved to pad 39A and prepared for launch June 13 on the station assembly flight. But NASA will only have one week to get Endeavour off the ground. A so-called "beta angle cutout" will kick in June 21, preventing any shuttle visits to the station until after July 11 because of temperature constraints related to the angle between the sun and the plane of the space station's orbit.

Moving up the Atlantis launch date by one day would buy one more day of insurance to get the Hubble mission off ahead of the military range operation and at the same time, provide more cushion for the June mission. If the Atlantis flight slips behind the range operation, Endeavour's flight would face a delay to mid-July.