Live coverage: Vega rocket launches with LISA Pathfinder

Three spacecraft built in Europe and Japan have completed their final joint tests to ensure they are ready for departure to Mercury on an Ariane 5 rocket late next year on the nearly $1.9 billion BepiColombo mission to survey the solar system’s innermost planet.

Engineers working on the James Webb Space Telescope, which had its launch delayed to 2020 earlier this year, recently discovered another problem during testing at the observatory’s prime contractor Northrop Grumman in Southern California.

An Ariane 5 rocket will fire into the sky from French Guiana just after sunset Wednesday and deliver nearly 12 tons of payload to an orbit reaching 22,000 miles up less than a half-hour later.