Snapshots from Atlas 5 launch

This photo gallery shows the U.S. Navy’s third Mobile User Objective System (MUOS) satellite being encapsulated in the rocket’s nose cone and being lifted atop the Atlas-Centaur vehicle. Liftoff is planned for Jan. 20.

The first images from the European-built Solar Orbiter mission are the closest ever taken of the sun, revealing previously unseen mini-flares nicknamed “campfires” that may offer hints about what makes the solar corona, or outer atmosphere, hotter than the sun’s surface.

SpaceX’s Falcon Heavy rocket rolled out of its hangar and up the ramp to pad 39A at NASA’s Kennedy Space Center in Florida, then was raised vertical at the seaside launch complex early Monday in preparation for a late-night liftoff with two dozen weather observation and technology demonstration satellites.