Endeavour gets ready launch

Launch pad technicians began filling shuttle Endeavour’s fuel tank on Monday for a launch attempt at 8:56 a.m. EDT (14:56 SA time) on a mission to deliver a long-awaited physics experiment and spare parts to the International Space Station.

Nasa had hoped Endeavour would be back from its final space mission by now, but the first launch attempt on April 29 was scuttled after a heater in one of the ship’s hydraulic power generators failed.

With no technical problems looming and a good weather forecast, workers began a three-hour task to pump more than 500000 gallons of liquid oxygen and liquid hydrogen into Endeavour’s fuel tank. The shuttle will drain the tank in 8,5 minutes, the time it takes to reach orbit.

The flight is the 134th in shuttle program history and the next-to-last before NASA retires its three-ship fleet. Sister ship Discovery completed its final mission in March and Atlantis is schedule to close out the program with a last cargo haul to the station in July.

Russian and European freighters will keep the station stocked with food, water and supplies in the immediate future.

NASA has hired two commercial companies — Space Exploration Technologies and Orbital Sciences Corp. — to fly cargo to the station as well. The firms are expected to begin station deliveries next year.

Crew transportation will be handled solely by Russia until US companies develop the capabilities. Then NASA wants to buy flight services, rather than develop and operate its own fleet to ferry astronauts to the station.

The shuttles are being retired due to high operating costs and to free up funds to develop new spaceships that can travel beyond the station’s 220-mile-high orbit.

Endeavour, the youngest of NASA’s shuttles, will making its 25th flight. It was commissioned as a replacement for Challenger, the shuttle destroyed in a 1986 launch accident that killed seven astronauts. Endeavour first flew in 1992.

“She’s got a lot of life left in her, but that’s not meant to be,” said shuttle launch director Mike Leinbach.

Endeavour carries the $2 billion Alpha Magnetic Spectrometer particle detector, a collaborative project of 600 physicists in 60 research organizations that is spearheaded by Nobel laureate Samuel Ting of the Massachusetts Institute of Technology. Once attached to the station, the detector will analyze high-energy cosmic rays for signs of dark matter, antimatter and other exotic phenomena.

The shuttle also will deliver a pallet of spare parts to the station.

The six-man veteran crew, led by Mark Kelly, is scheduled to spend 12 days at the station, helping to prepare it for operations after the shuttles are retired.

Kelly is married to US Representative Gabrielle Giffords, who is recovering from an assassination attempt in January that killed six and left 12 others injured. The Arizona Democrat left her rehabilitation hospital in Houston on Sunday and traveled to Florida to watch Endeavour’s launch.