Q&A with Sara Seager, deputy director of science on NASA’s TESS mission (members only)

Two small Chinese satellites designed to detect gamma-ray bursts associated with gravitational waves launched Wednesday on a Long March 11 rocket, beginning an astrophysics research mission to study black holes and neutron stars.

The next test of a critical safety system on SpaceX’s human-rated Dragon spaceship will be delayed, likely until some time next year, as the company adjusts the development schedule for the new commercial crew capsule designed to take astronauts to the International Space Station.

SpaceX moved closer to its next launch with a successful hold-down engine firing Saturday at the Kennedy Space Center in Florida, sailing through a readiness check for a planned liftoff Wednesday with a clandestine U.S. government payload named Zuma.