The TRIPLE project – Towards technology solutions for life detection missions

The exploration of ocean worlds in the outer Solar System, for example, the Jovian moon Europa and the Saturnian moon Enceladus, are of particular interest for the search for extraterrestrial life. Direct in situ exploration of moons harbouring significant amounts of liquid water beneath their ice surface poses many challenges and requires a sophisticated technological approach. The TRIPLE project (Technologies for Rapid Ice Penetration and Subglacial Lake Exploration) initiated by the German Space Agency at DLR forms a national consortium to work on robotic technologies for sub-ice exploration. The planned system consists of the fully autonomous, untethered miniature submersible robot, called nanoAUV, the IceCraft, a melting probe for penetrating the ice with the nanoAUV as payload, and an astrobiology in-situ laboratory, the AstroBioLab, to study fluid and sediment samples.

Beneath a several kilometre-thick ice-shell of the moons considered here, global oceans are well hidden and not easily accessible, posing extreme challenges for any robotic exploration as it is addressed in the TRIPLE project. Therefore, ice drilling and state-of-the-art technologies need to be developed to meet the manifold requirements. In view of future missions to icy moons, in TRIPLE, an analogue terrestrial demonstration is intended for first time exploration of a subglacial lake at the Dome-C region in Antarctica. The Dome-C mission requires a retrievable melting probe that can penetrate a 4-kilometre-thick layer of ice. It is essential for the mission that the melting probe is able to detect and avoid obstacles along its trajectory and to anchor itself at the ice-water interface for release and support of the nanoAUV into the water. The AstroBioLab concept provides an automated sample analysis laboratory for habitability investigations. It shall not only be able to detect various biosignatures in samples taken from the subglacial habitats, but shall also provide unequivocal evidence of life. For the field test in a terrestrial analogue setting, portable and robust devices using fast analysis methods are particularly suitable, which, as far as possible, should not require time-consuming sample preparation. In this contribution, we give an overview of the TRIPLE project and report on its current status.