| The unpiloted vehicle's supersonic combustion ramjet, or scramjet, ignited as planned and operated for the duration of its hydrogen fuel supply. |
| To prepare for the Mach 10 flight, the third scramjet was upgraded slightly. |
| The task of igniting a scramjet, with air going through the engine at supersonic speed, has been likened to lighting a match in a hurricane. |
| A conventional jet engine does this as well but theoretically a scramjet can operate at much higher speeds. |
| Like the comparatively slower ramjet counterpart, the scramjet has a simple mechanical design with no moving parts. |
| The engine, which will be provided by the Air Force, will be a dual-mode scramjet capable of running as a ramjet or scramjet. |
