Q&A with Eric Smith, JWST program director

After replacing a faulty inertial measurement system blamed for a scrubbed launch attempt Sunday, a Soyuz rocket headed to space from French Guiana today with five satellites, including the next spacecraft for Europe’s multibillion-dollar Earth observing network and a French experiment to probe the validity of Einstein’s theory of general relativity.

Rocket Lab’s launch team canceled a launch attempt Sunday in New Zealand after discovering a misbehaving video transmitter on the Electron booster set to loft a small U.S. military satellite into orbit to test an innovative antenna design. After replacing the transmitter, Rocket Lab announced the launch is set for Thursday (U.S. time) to wait for better weather.

A SpaceX Falcon 9 rocket lifted off from Space Launch Complex 4-East at Vandenberg Air Force Base in California at 12:17 p.m. EST (9:17 a.m. PST; 1717 GMT) Saturday with an oceanography satellite jointly developed by U.S. and European space and weather agencies. The rocket’s first stage booster returned to a bullseye landing back at Vandenberg.