Live coverage: Space station crew home after 115-day mission

The launch of a Japanese X-ray telescope and robotic lunar lander has been delayed to no earlier than August, and the launch schedule for another Japanese mission to return samples from a moon of Mars is in doubt as engineers investigate the failure of Japan’s first H3 rocket last month.

In a brief ceremony Saturday, veteran cosmonaut Gennadi Padalka, the most experienced spaceman on or off the planet, turned over command of the International Space Station to NASA astronaut Scott Kelly, who along with cosmonaut Mikhail Kornienko is midway through a nearly yearlong stay in orbit.

SpaceX is preparing this week for the second flight of the upgraded “Block 5” version of the company’s Falcon 9 rocket, and a hold-down firing of the booster was accomplished Wednesday at Cape Canaveral ahead of a middle-of-the-night launch this weekend with a Canadian-owned commercial communications satellite. The static fire test occurred at 5 p.m. EDT (2100 GMT) Wednesday.