NASA's space shuttle Endeavour is schedule to launch for the 25th and final time Monday (May 16), at 8:56 a.m. EDT (1256 GMT).

Endeavour is scheduled to blast off from Launch Pad 39A at NASA's Kennedy Space Center. Odds of good weather conditions are 70 percent, officials said over the weekend.

Commander Mark Kelly will lead a crew of six on a 16-day trip to the International Space Station. The shuttle will carry into space a $2 billion astrophysics experiment called the Alpha Magnetic Spectrometer (AMS). The bus-sized device contains a magnet to search for space particles that astronomers hope will explain cosmic mysteries like dark matter and antimatter.

The launch attempt will be the second, after broken heaters kept the shuttle earthbound April 29.