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

Lockheed Martin, the largest U.S. defense contractor, announced late Sunday that it has reached a deal valued at $4.4 billion to acquire Aerojet Rocketdyne, a supplier of engines to NASA’s Space Launch System moon rocket and United Launch Alliance’s Atlas, Delta, and Vulcan rockets.

SpaceX’s Falcon 9 rocket is set for liftoff from Cape Canaveral on Tuesday carrying the U.S. Air Force’s next GPS 3-series navigation satellite destined for an orbit more than 12,000 miles above Earth.

Fresh off its fifth passage through a gap between Saturn’s atmosphere and rings, NASA’s robotic Cassini spacecraft is looping toward a close brush with the planet’s innermost ring next week, when the probe will again use its high-gain antenna as a shield against icy particles that may lie in its path.