Q&A with Scott Bolton, principal investigator on NASA’s Juno mission

Lockheed Martin has proposed a semi-reusable resupply platform to send up cargo to the International Space Station beginning in 2018, adding another competitor to a crowded list of companies bidding to win multibillion-dollar contracts from NASA.

The European Space Agency’s $1.7 billion robotic Jupiter Icy Moons Explorer mission is ready for liftoff Thursday from French Guiana, beginning an eight-year cruise to the solar system’s largest planet before becoming the first-ever spacecraft to orbit one of Jupiter’s moons in the 2030s.

NASA’s InSight spacecraft plunged into the rarefied atmosphere of Mars at a speed of more than 12,000 mph Monday and braked to a gentle touchdown, setting the stage for a two-year surface mission to probe the planet’s deep interior.