Deep ocean mapping and exploration has posed a unique and seemingly impossible challenge to scientists. While autonomous aquatic robots have proved to be instrumental in solving this problem, they require careful monitoring and maintenance to ensure they last as long as possible. However, a new design may be able to remove the need for constant check-ups and offer over three months of uninterrupted exploration.
The new robot is called the Sounding Oceanographic Lagrangrian Observer Thermal RECharging, or SOLO-TREC for short, and was designed and assembled by engineers from NASA, the US Navy and a handful of universities. What separates the SOLO-TREC from other similarly designed autonomous ocean-going robots is that it can actually provide enough energy to keep itself going indefinitely.
By using a thermal recharging cycle based on the temperature variations caused by depth, the SOLO-TREC can convert heat energy into mechanical energy, which will in turn become stored electrical energy. The whole system is centered on carefully blended substances known as "phase change materials." As the robot descends, the temperature will drop, causing these phase change materials to contract. This allows a chamber to fill with oil and then seal to prevent any loss of pressure. As the robot ascends, the phase change substance will warm and expand, causing the oil to drive a hydraulic motor housed inside the SOLO-TREC.
Ten individual tubes of this phase change material are installed on the prototype, and they are able to produce enough energy to keep all of the scientific instruments up and running, as well as provide power for the robot to maintain a certain buoyancy.
The prototype SOLO-TREC robot recently concluded a 3 month test just off the south western coast of Hawaii. It was launched on the 30th of November, and was allowed to float freely for just over 3 months. During that time, it completed over 100 dives down to a depth of 1640 feet followed by a gradual return to the surface.
SOLO-TREC Test Voyage
Another test, this one spanning up to a year, is being currently being planned and will serve as a final test for the design. The public can keep tabs on the prototype SOLO-TREC by visiting a website set up by the team that will track the progress vie GPS.