CAPE CANAVERAL, Fla. - NASA will try to launch Atlantis on the first space shuttle mission of the year in early June, almost three months later than originally planned, so that technicians can finish repairing its hail-damaged fuel tank, officials said Tuesday.

An osprey sits on its nest as the space shuttle Atlantis rolls back for repairs at the Kennedy Space Center in Cape Canaveral, Florida March 4, 2007. [AP]

The new launch date now was set for no earlier than June 8.

NASA managers had been studying for weeks whether to finish repairing the tank and use it for Atlantis' mission or swap it out with another tank.

But NASA managers said they were pleased with the progress of repairs that already have been made.

"We don't see any showstoppers in front of us ... but there is still a lot of work to be done," said Bill Gerstenmaier, NASA's associate administrator for space operations.

Golfball-sized hail left thousands of dings on the foam insulation on Atlantis' fuel tank as it sat on the launch pad in February. The space shuttle was rolled off the launch pad and sent back for repairs to the Vehicle Assembly Building, forcing NASA to miss the original March 15 launch date.

The foam is used to prevent dangerous ice from building up on the tank during fueling on the launch pad.

The insulating foam is of special concern to NASA since a chunk of it flew off during space shuttle Columbia's launch in 2003 and struck the orbiter. The damage allowed fiery gases to penetrate Columbia during re-entry, breaking up the craft and killing its seven astronauts.

NASA redesigned the external tank, removing large amounts of foam, before last year's three successful shuttle missions. The space agency plans another design change to the tank before the shuttle program ends in 2010.

With the extra time, NASA engineers also decided last week to inspect Atlantis' propulsion lines to make sure a silicon rubber mold material wasn't left behind in them. A small amount of the material which is used to check for cracks in the lines was found in one of the engines used during Discovery's mission last December and another engine that flew on Discovery last July.

Atlantis' three engines were to be removed so technicians can get to the propulsion lines, but the inspection wasn't expected to affect the launch schedule, said NASA spokeswoman Tracy Young.