Hertfordshire Pedal Aeronauts, builders of the HPA巨嘴鳥(英语:HPA Toucan) human-poweredaircraft 漢斯·彼得·安文(英语:Hans Peter Anvin),一位在1972年出生的瑞典程式設計師,名字經常縮寫成HPA。
air-breathing scramjet-powered vehicles that are launched and land horizontally, nuclear-powered vehicles, and even jet-engine-powered vehicles that can fly