Q&A with Rolf de Groot, head of ESA’s robotic exploration office

The 13th and 14th operational members of Europe’s Galileo navigation satellite network are set for liftoff Tuesday aboard a Soyuz rocket from French Guiana. Track the progress of the flight with this timeline of key events.

Teams working at the Kennedy Space Center in Florida last week connected a U.S.-built Orion crew module with its European-made power and propulsion element for the first time, a significant accomplishment ahead of the spacecraft’s shipment to Ohio this fall for testing inside the world’s largest vacuum chamber.

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.