Boeing X-20 Dyna-Soar

A drawing in [Vous devez être inscrit et connecté pour voir ce lien] magazine from before the project's cancellation depicts the craft dipping down into the atmosphere, skimming the surface, to change its orbital [Vous devez être inscrit et connecté pour voir ce lien].

It would then fire its rocket to resume orbit.

This would be a unique ability for a spacecraft, for the laws of [Vous devez être inscrit et connecté pour voir ce lien] mean it requires an enormous expenditure of energy for a rocket to change its orbital inclination once it has reached orbit.

Hence the Dyna-Soar could have had a military capacity of being launched into one orbit and rendezvousing with a satellite, even if the target were to expend all its propellant in changing its orbit.

Acceleration forces on the pilot, however, would be severe in such a maneuver.

Unlike the later Space Shuttle, Dyna-Soar did not have wheels on its [Vous devez être inscrit et connecté pour voir ce lien] as it was thought the rubber would burn during re-entry.

Instead [Vous devez être inscrit et connecté pour voir ce lien] developed retractable wire-brush skis made of the same René 41 alloy as the airframe.