ARCHEOLOGIA NUOVA

Shuttle, nuovo lancio ...

Da:"Reuters.com"

NASA readies for next week's space shuttle launch

Liftoff of the Discovery, NASA's senior spaceship, is targeted for Thursday at 4:50 p.m. (2150 GMT) from the Kennedy Space Center.

Problems with the ship's fuel tank have kept the mission on hold since November. An unrelated hydrogen leak forced NASA to cancel a launch attempt on November 5.

Technicians then discovered a crack in the insulating foam that covers the shuttle's fuel tank, a potentially serious safety issue.

"The teams have done a great job. I think we're ready to go next week," Bill Gerstenmaier, NASA's associate administrator for space operations, told reporters.

In 2003, space shuttle Columbia was damaged by a piece of foam insulation that fell off the tank and hit the ship's wing during liftoff. The shuttle broke apart as it flew through the atmosphere for landing 16 days later, killing all seven crewmembers aboard.

The crack in Discovery's insulation proved more than skin deep. Engineers discovered cracking in underlying support beams that provide structure between the tank's liquid hydrogen and liquid oxygen compartments.

NASA worked on the problem for two months before determining that a slight defect in the batch of aluminum-lithium used to manufacture the tank's beams was the root cause. Technicians repaired the cracks and reinforced the beams.

The shuttle will be carrying an Italian-made storage room that will be added to the $100 billion space station, a project of 16 nations nearing completion after 12 years of construction.

The shuttle also will deliver food, science equipment and supplies for the six crewmembers aboard the station and a prototype humanoid robot.

Two spacewalks are planned during Discovery's weeklong stay at the station.

The 30-year-old shuttle program is ending due to high operating costs and to free up funds to develop rockets and spaceships that can fly beyond the station's 220-mile-high (355-km) orbit.

The Obama administration wants to spur private companies to get into the space taxi business, freeing NASA to focus on deep space exploration and new technology development.

(Editing by Kevin Gray and Peter Cooney)