When president Trump released his budget proposal earlier this year, space enthusiasts were dismayed to learn that it didn't include funding for NASA's mission to place a lander on Europa. Although it is just one of Jupiter's 67 moons, Europa is unique in that it is thought to have an ocean of liquid water under the icy, red-veined crust that covers its surface, which makes it the best candidate in the solar system for hosting alien life.

All hope is not lost for the subsurface exploration of Europa. Just last week, a French researcher suggested that NASA and the European Space Agency could pursue a joint Europa lander mission in lieu of the NASA's solo mission. A spokesperson for NASA said that neither agency is developing such plans at this time.

This is particularly good news for the folks at Stone Aerospace, who have spent the last few years developing ARTEMIS, an autonomous submarine that is pioneering the technology that they hope will one day be used to explore Europa's ocean. In 2015, ARTEMIS was given its first field test off the coast of Antarctica and the results of these test runs were presented at NASA's astrobiology conference last week. By all accounts, the mission was a huge success.

The submarine developed by Stone as part of a multi-million-dollar NASA grant is nearly 14 feet long, weighs over 2,800 pounds, and is capable of traveling a little over 3 miles on its own before returning and docking itself at its pickup point. Obviously, such a large craft would be prohibitive for any space mission to Europa. ARTEMIS was made from off-the-shelf parts and meant to test autonomous navigation and sample retrieval systems. The actual sub used on Europa would have to be entirely custom made to lower its bulk.