Q&A with Michel Denis, ExoMars flight director

Researchers using data from a NASA satellite orbiting Mars said Monday they have found clear evidence of intermittent flows of salty water on the red planet, the first “unambiguous” signs of liquid water on the frigid world and a possible indicator of microbe-friendly environments below the surface.

SpaceX chief executive Elon Musk on Tuesday outlined an ambition to send humans to Mars with methane-fueled reusable spaceships and the largest rocket ever built, an effort he said will likely require government support and initially cost billions of dollars to develop and test.

Europe’s nearly $8 billion Galileo navigation system, an analog to the U.S. GPS satellite network, is hitting a stride in production and launches, with another two spacecraft encapsulated Wednesday inside the fairing of a Soyuz rocket for liftoff next week.