Q&A with Michel Denis, ExoMars flight director

NASA’s $8.8 billion James Webb Space Telescope has completed critical end-to-end testing in a giant vacuum chamber at the Johnson Space Center, proving the telescope will work properly in the deep cold of space, bring starlight to a sharp focus and precisely track its astronomical targets when launched in 2019.

A wave of clock failures on Europe’s Galileo navigation satellites has not knocked any of the craft offline, but officials want to better understand the problem before launching more satellites into the fleet.

Keith Gendreau, an astrophysicist at NASA’s Goddard Space Flight Center, recently spoke with Spaceflight Now about a new experiment on the International Space Station to demonstrate X-ray communications in space for the first time.