The ALTUS I, flown for the Department of Energy/Sandia National Laboratory by the Naval Postgraduate School, incorporates a single-stage turbocharger, while the ALTUS II, built for NASA's Environmental Research Aircraft and Sensor Technology program, sports a two-stage turbocharger to enable the craft to fly at altitudes in the 65,000-foot range.

The ALTUS II and its sister ship, the ALTUS I, are variants of the Predator surveillance drone built by General Atomics/Aeronautical Systems Inc. They are designed for high-altitude, long-duration scientific sampling missions, and are powered by turbocharged piston engines.