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

Culminating years of construction and testing, a $1.2 billion satellite designed to spot and track enemy missiles threatening the United States homeland, its deployed military forces abroad or allied nations will ascend to a surveillance post in space Thursday.

A European Ariane 5 rocket is scheduled for blastoff  Tuesday from a jungle launch pad in South America with two geostationary telecom payloads — one owned by a Saudi Arabian operator and built in Colorado by Lockheed Martin, and another for India’s space agency.

An armored re-entry capsule carrying pristine specimens from an asteroid streaked into Earth’s atmosphere and parachuted to a landing in the Australian outback Saturday, bringing home extraterrestrial rocks that could hold clues to the origin of life on Earth.