Photos: Atlas 5 rolls out for launch

Using precise autonomous navigation algorithms, NASA’s OSIRIS-REx spacecraft will descend to the surface of an asteroid next year, aiming to retrieve rock specimens for return to Earth from a gravelly pit flanked by hazardous boulders, scientists said Thursday.

Lockheed Martin, the largest U.S. defense contractor, announced late Sunday that it has reached a deal valued at $4.4 billion to acquire Aerojet Rocketdyne, a supplier of engines to NASA’s Space Launch System moon rocket and United Launch Alliance’s Atlas, Delta, and Vulcan rockets.

The enigmatic X-37B spaceplane, launched into low-Earth orbit on an experimental military mission in 2015, continues to circle the planet despite a flurry of landing rumors.