Air Turbo Rockets

Air Turbo Rockets (ATRs) are a cross between turbojets and rockets. The basic version is an air breathing engine augmented with a rocket gas generator that drives a turbine and in-turn an air compressor. However, the concept can be extended to an engine that can transition from this mixed mode to rocket only propulsion. That would allow the engine to operate both in our atmosphere as well as in space. Clark Lindsey discusses the concept briefly and points to additional links, which I've repeated:

• Selenian Boondocks - Turbo Rocket Upgrades
• The Air Turbo Rocket: An Introduction - Plasma Wind - May.29.09
• The Air Turbo Rocket: Performance Attributes (Part 1) - Plasma Wind - June.5.09
• The Air Turbo Rocket: Performance Attributes (Part II) - Plasma Wind - June.23.09
• ATR Applications: Tactical Missile Propulsion - Plasma Wind - July.08.09