Watch a time-lapse of the Crew Dragon access arm installation (members only)

Poised to loft a Russian-German X-ray astronomy observatory into space Friday, a Proton rocket returned to its launch pad Tuesday at the Baikonur Cosmodrome in Kazakhstan after a three-week delay to replace a drained battery on the vehicle.

Northrop Grumman’s Cygnus supply ship set for liftoff Saturday will deliver to the International Space Station the final hardware for a series of ambitious spacewalks later this month to install a new coolant system on the Alpha Magnetic Spectrometer, a $2 billion particle physics experiment seeking the cosmic signatures of dark matter and antimatter.

SpaceX’s Falcon 9 rocket took off from the historic seaside launch pad 39A at NASA’s Kennedy Space Center on Monday, powered a classified NRO spy satellite into space, then the launcher’s first stage descended to a vertical landing at nearby Cape Canaveral Air Force Station.