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

SpaceX’s fired the engines of its Falcon Heavy rocket at launch pad 39A at 12:30 p.m. EST (1730 GMT) on Wednesday. The crucial pre-launch engine test has been repeatedly delayed since the rocket returned to the launch pad earlier this month.

A launch readiness review Friday cleared an Ariane 5 rocket for liftoff Tuesday with two communications satellites for Arabsat and India, the first three missions from Europe’s spaceport in French Guiana scheduled in less than 40 days.

SpaceX’s Dragon cargo capsule arrived at the International Space Station early Sunday with 3.5 tons of supplies and experiments, including an inflatable room to test out technologies for future use on deep space missions. British astronaut Tim Peake captured Dragon with the robotic arm at 7:23 a.m. EDT (1123 GMT).