Photos: Atlas 5 rocket aims for International Space Station

The year ended with a deluge of big news, reminding us of the risks of spaceflight and the thin margins between success and failure on the final frontier. 2014 was also a year of breakthroughs in the exploration of the solar system and the future of human spaceflight.

The Air Force’s robotic X-37B mini space shuttle swooped out of obscurity today after 718 days spent in orbit on a secretive military mission, touching down at the Kennedy Space Center’s orbiter runway on autopilot, the military announced on Twitter.

Taking advantage of available astronaut time, the International Space Station’s crew will cast off the commercial Orbital ATK Cygnus freighter on Sunday morning nearly six weeks ahead of schedule.