SpaceX launches supplies to space station

The SpaceX company returned to orbit Friday, launching fresh supplies to the International Space Station after more than a month's delay and setting the stage for urgent spacewalking repairs.

The Dragon cargo ship will reach the orbiting lab on Sunday - Easter morning. That pushes the spacewalking repairs to Wednesday; NASA wants a bad computer replaced before something else breaks.

This was the second launch attempt this week for SpaceX. NASA's commercial supplier had a leaky rocket valve Monday. The valve was replaced, and the company aimed for a Friday liftoff despite a bad forecast. Storms cleared out of Cape Canaveral just in time for the afternoon launch.

The unmanned cargo ship contains 2.5 tons of station supplies, including material originally intended for the spacewalking repairs.

A critical backup computer failed outside the space station last Friday. The primary computer is working fine, but numerous systems would be seriously compromised if it broke, too. A double failure also would hinder visits by the Dragon and other vessels.

"It's imperative that we maintain" backups for these external command-routing computer boxes, said flight director Brian Smith said Friday. "Right now, we don't have that."

NASA decided late this week to use the gasket-like material already on board the space station for the repair, instead of waiting for the Dragon. Astronauts trimmed the thermal material Friday to fit the bottom of the replacement computer, and inserted a fresh circuit card.

Much-needed food is also aboard the Dragon, along with a new spacesuit and spacesuit replacement parts. NASA wants all these things at the space station as soon as possible.

The shipment is close to five weeks late. Initially set for mid-March, the launch was delayed by extra preparation, then damage to an Air Force radar and, finally on Monday, the rocket leak.

Earlier, as the countdown entered its final few hours, NASA's space station program manager Mike Suffredini said an investigation continues into the reason for last year's spacesuit failure. The helmet worn by an Italian astronaut filled with water from the suit's cooling system, and he nearly drowned during a spacewalk.

Routine U.S. spacewalks are on hold until engineers are certain what caused the water leak. The upcoming spacewalk by the two Americans on board is considered an exception because of its urgent nature.

NASA is paying the California-based SpaceX - Space Exploration Technologies Corp. - and Virginia's Orbital Sciences Corp. to keep the orbiting lab well stocked after the end of its space shuttle program. Russia, Japan and Europe also make periodic deliveries.