Last year, NASA announced the development of a new vehicle seemingly straight out of science fiction: a space submarine. Since so many of the moons in our solar system are believed to have potentially life-sustaining oceans rife with hydrothermal activity beneath their icy surfaces, an interplanetary submarine may be the perfect tool to search the unexplored waters of alien worlds for any signs of life. To that end, NASA and the European Space Agency (ESA) want to send a robotic submarine to Europa, one of the largest of Jupiter’s 67 moons and a prime candidate in the search for alien life in the solar system.
According to the joint NASA/ESA press release describing their Joint Europa Mission (JEM), both agencies believe there is a good chance Europa might sustain alien life of some kind:
There is a consensus in the planetary community that Europa is the closest and probably the most promising target to search for extant life in our solar system. The Galileo discovery of a sub-surface ocean likely in direct contact with a silicate floor that could be a source of the key chemical species needed for the build-up of biomolecules. [...] Europa is likely habitable, and [we] strongly support a scientific plan to go there and see if it is indeed inhabited.
To prepare for such a mission, NASA has funded and is currently testing submarine designs. One such sub designed by Stone Aerospace, ARTEMIS, is currently being tested in Antarctica. NASA revealed the results of some of the preliminary tests at this year’s NASA Astrobiology Science Conference (AbSciCon). The difficulties of sending a submarine to a distant moon, getting through the moon’s thick icy surface, and then operating a remote mission all from a single borehole are many, and ARTEMIS will have to undergo years of testing before it's ready to be sent to explore Europa.
The recently-published tests of the ARTEMIS submarine were designed around three main objectives:
(1) the ability to reliably conduct operations in completely ice covered waters accessible only via a single borehole for deployment and recovery, (2) the ability to characterize the physical and geochemical environment, and (3) the ability to search for life at the ice-water interface and conduct detailed investigations (in this case, to take and return water samples) in identified areas of interest.
According to the presentation given at AbSciCon 2017, the tests were all successful. Don’t get too excited yet, though. The Joint Europa Mission will first have to send a probe to conduct a flyby of Europa in order to determine where its nuclear-powered laser drill could realistically break through the 10-15 miles of ice covering Europa. You read that right: nuclear-powered laser drill. Those Europan lifeforms are gonna love us.