Live coverage: Four astronauts return home after 167 days in space

A workhorse Soyuz booster thundered to life and climbed into a dark Kazakh sky Friday, carrying NASA astronaut Scott Kelly and cosmonaut Mikhail Kornienko on a four-orbit voyage to the International Space Station to kick off a marathon 342-day mission, the longest flight ever attempted by an American.

A commercial Cygnus supply ship departed the International Space Station on Friday for an extended mission to deploy five nanosatellites and conduct other experiments before re-entering the atmosphere and burning up with more than two tons of trash.

A critical test firing Saturday of the four main engines powering the first stage of NASA’s gargantuan Space Launch System moon rocket is the final major hurdle before the fully assembled booster’s costly, oft-delayed launch late this year on an unpiloted test flight.