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

Crew members on the International Space Station over the weekend continued trying to pinpoint the location of a small air leak in the research outpost’s Russian Zvezda service module, one of the oldest sections of the orbiting laboratory.

A Ukrainian-built Zenit booster and a Russian-made Fregat upper stage launched with an Angolan communications satellite Tuesday from the Baikonur Cosmodrome in Kazakhstan, but engineers lost contact with the spacecraft soon after its deployment in orbit more than 22,000 miles above Earth.

The first Ariane 5 launch since a mission flew off course Jan. 25, deploying two communications satellites into an off-target orbit, is underway. Liftoff with the DSN 1/Superbird 8 and Hylas 4 communications satellites occurred on time at 2134 GMT (5:34 p.m. EDT).