Q&A with Keith Gendreau, principal investigator of the first X-ray space communications experiment (members only)

A rocket booster SpaceX used to launch a planet-hunting NASA observatory two months ago fired again Saturday at Cape Canaveral, clearing a major pre-flight checkout before blastoff June 29 with a space station supply ship.

The slide system differs notably from the slide wire basket system used over at Launch Complex 39A at NASA’s Kennedy Space Center. NASA officials said pad 40 will be ready for astronaut launches this year.

A three-man crew from Russia, the United States and Italy climbed inside a Soyuz spacecraft and rocketed into orbit Saturday from the Baikonur Cosmodrome in Kazakhstan on course for the International Space Station.