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

Boeing and SpaceX hope to launch commercial crew ferry ships on long-awaited test flights later this year, but both companies face major challenges getting the spacecraft certified before late 2019 when seats aboard Russian Soyuz spacecraft will no longer be easily available for NASA space station crews, officials told lawmakers Wednesday.

Two days after launch from Kazakhstan, a Russian Soyuz ferry ship glided to a smooth docking with the International Space Station Saturday, bringing a veteran cosmonaut, a Frenchman making his first flight and NASA’s most experienced female astronaut to the lab complex.

Japan’s H-2 Transfer Vehicle has accomplished five flights to the International Space Station, delivering tons of food, clothing and crew provisions, instruments to look at ozone chemistry and investigate dark matter, and critical hardware to keep the research complex operating.