NASA hopes to fix shuttle for flight in May

CAPE CANAVERAL, Florida (Reuters) - Repairing damage to a space shuttle fuel tank from a freak hailstorm will push the next launch of Atlantis from April to mid-May at the earliest, NASA managers said on Wednesday.

NASA intended to launch the shuttle on March 15, but the ship had to be returned to a processing hangar for repairs to its fuel tank insulation.

The foam was damaged during a severe hailstorm that passed over the Kennedy Space Center in Florida on February 26 as Atlantis was being prepared for flight at a seaside launch pad.

NASA has until May 21 to launch the shuttle, or it must wait until June 7 or 8. Between those dates, the sun's position is unsuitable for the shuttle to dock at the International Space Station.

"It is possible that we could still squeak into the May part of the launch window," shuttle program manager Wayne Hale said in a conference call with reporters.

NASA is assessing repair techniques, with particular concern to a new type of foam that would have to be manually sprayed around the tank's badly damaged top portion.

About 1,600 dings and divots on the tank will need to be repaired, said John Honeycutt, the deputy manager of the shuttle tank program.

If repairs prove more complex, NASA could decide to replace Atlantis' damaged tank with a new one, positioning the shuttle for a launch in June.

"We're going to fix this tank and fix it right, or we're going to (replace) it," Hale said.

NASA has been particularly sensitive to shuttle tank safety since the 2003 Columbia accident, which was triggered by a piece of foam insulation falling off the tank and damaging the shuttle's wing during liftoff.

The impact broke open a heat panel on the wing, which allowed superheated atmospheric gases to get inside the structure as Columbia soared through the skies for landing 16 days later. The shuttle broke apart over Texas, killing all seven crew members.

Hale said the shuttle program will not succumb to scheduling pressure despite a firm deadline to retire the fleet by 2010.

"We're going to fly (Atlantis) when it's safe to fly and not before," he said.

Delaying Atlantis' flight to May or June will force NASA to drop one of five shuttle missions originally planned for this year, but Hale said the lost time will be made up within about 12 months.

"It certainly does not affect our capability of completing the ISS by 2010," Hale said, referring to the International Space Station.

The agency needs at least 13 flights to finish the job.

NASA also plans two resupply missions to the $100 billion station, which is a project of 16 member countries, and a servicing call to the Hubble Space Telescope before retiring the shuttle fleet.