During the 1950s, several zero-length launch (ZELL) systems were tested but not put into service. They used expendable solid-rocket boosters to allow standard fighter jets to take off without a runway, although landing still required one.

I sought to design an improved and reusable ZELL system which would also work for landing. The main innovations are to use rocket pods compatible with standard hardpoints, and to combine nitrous oxide (a self-pressurizing oxidizer) with the aircraft's fuel into a liquid rocket engine. The oxidizer load is enough for one sortie.

The STOL procedures are simple but a bit nerve-raking :
- On launch, the brakes are engaged and the engine pushed to full throttle. The rocket pods are ignited and stay on until the horizontal speed is above the stall speed.
- To land, the airplane is put into a deliberate flat stall and the pods control the descent rate.