Q&A with Alvaro Gimenez, ESA’s director of science

Extra testing of the James Webb Space Telescope and delays in assembling the powerful observatory will push back the $10 billion mission’s launch by at least six months to early 2019, officials announced last week as the telescope successfully completed an extensive performance test inside a cryogenic vacuum chamber in Houston.

The European Space Agency’s $1.6 billion Rosetta spacecraft closed in Thursday for a deliberate crash landing on the surface of comet 67P/Churyumov-Gerasimenko early Friday, a slow-motion kamikaze plunge to bring the enormously successful mission to an end after more than two years of unprecedented close-range observations.

The Airbus-built Solar Orbiter spacecraft has been closed up inside the payload fairing of a United Launch Alliance Atlas 5 rocket in preparation for liftoff from Cape Canaveral in February on a joint mission between the European Space Agency and NASA.