Watch a replay of the launch of a Japanese navigation satellite

China launched an innovative satellite Wednesday that will look for X-ray signals from pulsars, the fast-spinning super-dense remnants of collapsed stars, to determine its exact location in space.

A full-scale model of Virgin Orbit’s air-dropped small satellite launcher, filled with water and antifreeze instead of rocket fuel, dropped from the wing of a modified Boeing 747 carrier jet Wednesday over a test range at Edwards Air Force Base in California, paving the way for the company’s first space mission later this year.

Six RD-276 engines powered a Russian Proton rocket off the launch pad Wednesday at the Baikonur Cosmodrome in Kazakhstan, boosting a television broadcast payload for Eutelsat and the first commercial robotic satellite servicing spacecraft into orbit.