Nasa confirms ocean moon mission
The Europa Clipper mission will target the ice-encrusted moon of Jupiter, which is considered a prime target in the search for life beyond Earth.
Below its icy shell, Europa is thought to hold a 170km-deep body of water.
This could have the right conditions for biology.
Due to launch in 2025, the Europa Clipper mission has now passed a stage called Key Decision Point C, a crucial marker on the road to the launch pad.