Live coverage: Space station crew safely returns to Earth

Two astronauts floated outside the International Space Station early Tuesday and replaced one of the grapple fixtures on the end of the lab’s robot arm, the first of two excursions over the next week to complete a complex overhaul that began with a pair of spacewalks last October.

This is the launch timeline to be followed by the Atlas 5 rocket’s ascent into space from Cape Canaveral with NASA’s Mars 2020 mission.

A small spacecraft built for the Russian military lifted off Thursday on top of a modified Soyuz booster, beginning a mission to reportedly test a compact Earth-imaging platform that could be used on future spy satellites.