Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

An Indian Polar Satellite Launch Vehicle lifted off at 0000 GMT Wednesday (8 p.m. EDT Tuesday) carrying a radar observation satellite to collect imagery in support of military, intelligence and environmental agencies.

The 60 satellites SpaceX is set to launch Wednesday night, beginning the build-out of a broadband network of orbiting spacecraft that could eventually number thousands, are based on a new flat-panel design, with krypton-fueled plasma thrusters, high-power antennas, and a capability to autonomously steer away from other objects in space.

NASA’s Mars Curiosity rover, slowly making its way up the side of a towering mountain of sedimentary rock at the center of its Gale Crater landing site, has found fresh evidence for the red planet’s past — and possibly present — habitability, scientists reported Thursday.