These satellite images, taken less than a month apart by France's new Pleiades optical-imaging spacecraft, show the mile-wide trail of devastation left by the EF5 tornado that tore through Moore, Okla., on May 20. The image on the left was collected on April 29, and the one on the right on May 23.

Concepts for meeting Mars science priority evolving

Uncertainty hits defense contractors, but civil airframers take up the slack

The U.S. National Oceanic and Atmospheric Administration (NOAA) is taking the unusual measure of activating an in-orbit Geostationary Operational Environmental Satellite (GOES) spare as experts try to rescue the primary spacecraft, which that has failed to transmit imaging and sounding data for a second time in less than a year.

NASA’s 4,300-sq-ft behemoth is slated to fly next year.

The first Canadian command of the International Space Station ends safely with this May 14 parachute landing of Soyuz TMA-07M in southern Kazakhstan. Onboard were Canada's Chris Hadfield, the first of his countrymen to command an ISS mission increment; U.S. astronaut Tom Marshburn, and cosmonaut Roman Romanenko. Throughout Hadfield's nearly five months in orbit, the retired 53-year-old Canadian air force colonel exhibited his musical talents and skills as a photographer and with social media to share his experiences.

Setting down safely may be as difficult as getting there

Cold War model seen useful for U.S.-China space confrontation