A unique chamber tests pilotless aircraft for their ability to function at altitudes exceeding 67,000 ft. Engineers at Aurora Flight Sciences Corp. (Manassas, VA) designed, built, and operate the chamber, called the Ultra-High Altitude Test Facility. Aurora successfully tested its Perseus B drone in the 12- by 7-ft chamber. Ram air coolers, normally mounted under the Perseus wing and on the fuselage's side, were replaced with compact coolers in which liquid fluids cool the engine and turbos instead of the ram air. To simulate the low temperatures at high altitudes, a special low-temperature fluid with a freezing temperature of about -130C was pumped through the coolers. For details, e-mail Ben Russat at firstname.lastname@example.org.