The launch of U.S. space shuttle Endeavour on its final voyage will be no earlier than May 16, the U.S. National Aeronautics and Space Administration (NASA) announced Friday.
"NASA managers met Friday afternoon and determined space shuttle Endeavour will launch no earlier than Monday, May 16 at 8: 56 a.m. EDT (1256 GMT)," the space agency said in a statement, Xinhua reported.
Technicians will continue to repair and retest the electric circuitry that caused NASA to postpone the launch on April 29 less than three hours before liftoff, it said.
Endeavour's launch has been on hold since April 29 when engineers detected a failure in one of the two heater circuits associated with Auxiliary Power Unit (APU) 1. Heaters are required to keep the APUs' hydrazine from freezing on orbit. The failure appears to be a power problem within the aft load control assembly- 2, a box of switches controlling power feeds.
Endeavour will fly on its 25th and final flight to deliver the 2-billion-dollar Alpha Magnetic Spectrometer (AMS) particle detector to the International Space Station. AMS, a particle physics detector, is designed to search for various types of unusual matter by measuring cosmic rays. Its experiments are designed to help researchers study the formation of the universe and search for evidence of dark matter, strange matter and antimatter.
Endeavor, which has been promised to the California Science Center in Los Angeles upon its return, was the replacement ship for Challenger, which was lost in a 1986 explosion as it ascended over the Atlantic that killed seven astronauts.
It will be the second of NASA's three surviving shuttles to be retired. Sister ship Discovery, which will be transferred to the Smithsonian National Air and Space Museum, completed its last flight in March. Atlantis' final launch is scheduled for June 28.
When the U.S. space shuttle program officially ends later this year, the Russian space program's Soyuz capsule will be the only method for transporting astronauts to and from the station.