Northrop Grumman/DARPA's long-range submarine drone shaped like a robotic Manta Ray with the ability to go dormant on the seabed and recharge itself with the teledyne webb thermal buoyancy engine

Must add to Ace Combat universe....

https://www.sciencedirect.com/science/article/pii/S0029801823006947

"When the glider is in power-generation mode, the thermal buoyancy engine uses the thermal energy to change its buoyancy and drive the glider vertically with the assistance of an attitude adjustment unit. During the ascend and descend, the foldable turbine behind the hull opens and harvests energy."

commute music for the day..

Blade Runner — Memories of Green.

F16 I think