A Proton rocket lifted off from the Baikonur Cosmodrome in Kazakhstan with the Spektr-RG X-ray astronomy mission at 1230:57 GMT (8:30:57 a.m. EDT) Saturday.

A Vega rocket faltered minutes after liftoff from French Guiana at 9:53 p.m. EDT Wednesday (0153 GMT) and failed to reach orbit with a European-built reconnaissance satellite for the United Arab Emirates. The payload and launcher fell into the Atlantic Ocean, marking the first failure for the solid-fueled Vega launch vehicle.

NASA hopes to begin launching astronauts to the space station aboard Boeing and SpaceX capsules in the 2017 timeframe, but managers expect to still send crews up aboard Russian spacecraft as a hedge against problems that could force some astronauts to make an emergency landing.