A robotic “cryobot,” designed to tunnel down through thick ice caps and penetrate subterranean seas, is undergoing tests on the Matanuska glacier in Alaska. It paves the way towards one day exploring the underground oceans of Jupiter’s moon, Europa, or other icy moons of the Outer Solar System.

Europa is back on the menu for exploration. NASA’s budget for the 2016 fiscal year includes about $30 million for further development of the Europa Clipper concept, a mission to Europa that will seek possible signs of the icy moon’s habitability. However, being potentially habitable is not the same as being inhabited. To find life, a mission will ultimately have to land on the surface and go under the ice to the ocean below. Europa Clipper, if and when it launches sometime around 2025, will carry out reconnaissance of the surface for safe and scientifically interesting places to land. Crucially, however, the Clipper will not be carrying a lander with it.

“Assuming Europa is found to be potentially habitable, the next mission that follows may be able to land and perhaps try to get beneath the ice,” says Louise Prockter, a planetary scientist at Johns Hopkins University Applied Physics Laboratory and Pre-Project Deputy Scientist for the Clipper mission.