A roundup of this week's top aerospace and defense stories you may have missed.

Four NASA astronauts, all veterans with experience aboard the International Space Station, space shuttle or Russian Soyuz spacecraft, have been named to train to fly aboard the first U.S. commercial crew missions, tentatively planned for 2016-17.

Dawn responded as designed by stopping all activities (including thrusting), reconfiguring its systems to safe mode and transmitting a radio signal to request further instructions, said Marc Rayman, Dawn's mission director.

Credit: NASA, JHUAPL, SWRI As the New Horizons spacecraft nears its July 14 closest approach to Pluto, the images sent back by NASA’s Long Range…

Details of the critical technology at the core of an innovative hybrid hypersonic propulsion system for air and space systems have been unveiled for the first time by its British-based developer, Reaction Engines.

Timing flaw put temporary shutdown on New Horizon's data collection mission at Pluto. Science operations will resume July 7.

Spacecraft controllers and engineers are pushing to restore science operations on New Horizons, after an on-board anomaly took the probe offline and out of communications on July 4.

"...feels like Chrismas in July," say space station cosmonauts. "The presents are here."