If experiments on the ground are cool, experiments in the sky are cooler. And so we can count ourselves extra icey this week, as we got to see to high-flying studies. First, we chatted with aviation company UAV Turbines, which is building mini, watermelon-sized jet engines. Pourquoi? Turns out 500- to 1,000-pound drones need power to stay aloft, too, and the batteries that power smaller flyers aren’t always up to the task. Then we spoke to the designers and executives behind Rolls-Royce’s transformation of a Qantas jet that was still flying passengers last week into a very expensive flying testbed for experimental jet engines.