Video: Rosetta scientist Matt Taylor on the end of mission

Teams working in Northrop Grumman’s spacecraft factory in Southern California have connected the spacecraft and science modules of the James Webb Space Telescope for the first time, a major milestone as engineers prepare to verify a fix to tears in the observatory’s sunshield, and begin launch vibration and acoustic testing in the coming months.

A European environmental satellite launched Tuesday from Russia’s Plesetsk Cosmodrome to begin a mission of at least seven years measuring the height, color and temperature of the world’s oceans. The Sentinel 3A spacecraft lifted off aboard a Rockot booster at 1757 GMT (12:57 p.m. EST).

NASA’s New Horizons spacecraft raced past a frozen remnant of the solar system’s birth early New Year’s Day, phoned home to confirm a successful flyby and readied a treasure trove of pictures and other data for transmission back to eager scientists some 4.1 billion miles away.