UPDATE - There is a second Nextbigfuture article with more technical details.
Broomfield, Colorado-based Escape Dynamics announced July 17 it carried out a small-scale test in the laboratory of its beamed microwave thruster. In that test, the company beamed microwave energy to a thruster, heating helium propellant and generating a small amount of thrust.
Escape Dynamics designed and built a 100kW-class high power microwave system operating in a continuous wave (CW) mode at 92.3GHz. The system incorporates a gyrotron, a power conditioning unit designed to supply highly stable current and voltage and a modular power supply unit. The gyrotron and the power conditioning unit, which provides power to the gyrotron, are designed and built in-house by Escape Dynamics’ team and conform to the highest levels of performance and efficiency.
The primary application for the high power microwave system in our lab is to provide power to a wireless energy transfer system that delivers a microwave beam to externally powered engines. The beam is converted in the engine into a highly efficient, combustion-free thrust.
EDI is currently developing a 500kW CW system at 92.3GHz designed to fully support the needs of an orbital launch facility.
EDI’s external propulsion launch system will operate at a specific impulse above 750 seconds and this breakthrough increase in efficiency reduces the fraction of mass dedicated to propellant to less than 72%. The increase of 3x in the mass fraction dedicated to structure and payload for the first time opens doors for reusability and single-stage-to-orbit flight. Our first generation vehicle is optimized for 100-200 kg payloads and is designed to operate like an airplane: the vehicle flies into orbit, delivers the payload, re-enters the atmosphere after completing one or more orbits around Earth and lands back at the spaceport.
Key benefits of external propulsion:
* Space launch vehicles become fully and rapidly reusable.
* Cost per launch can eventually be reduced to $150 per kg.
* The need for combustion is eliminated, leading to safer and simpler launch vehicles.
* Useful payload fraction goes up from 1.5-3% to 8-12% and the structural mass is increased by 1.5-2x.
* Small satellites can be launched as primary payloads allowing higher degree of flexibility for customers.
* Space launch is effectively powered with electricity from the grid through a battery-storage system pioneered by the company, and in the long term can rely on renewable sources of energy.
Escape Dynamics is developing the first single-stage-to-orbit, reusable launch vehicle powered with external propulsion. In external propulsion energy required for launch is delivered from a ground-based phased array of microwave antennas designed to safely and efficiently beam flight-sustaining power to the space plane during the ascent and acceleration to orbital velocity. The energy is converted into thrust in a heat exchanger which absorbs microwaves into heat and couples the energy into the flow of hydrogen propellant. The heated hydrogen is exhausted through the nozzle creating thrust and accelerating the vehicle.
Externally powered engines designed by Escape Dynamics operate with specific impulse above 750s and propellant mass fraction below 72% (compared to almost 90% of chemical rockets) and for the first time enable reusable single-stage-to-orbit flight.
Escape Dynamics (EDI) is an advanced technology company developing electromagnetically-powered, reusable, single stage to orbit flight systems and is innovating in core technologies required for next generation aerospace systems such as wireless energy transfer, high power microwaves, and next generation propulsion and materials. The company was co-founded by Richard F. Schaden and a team of Caltech scientists with Dr. Dmitriy Tseliakhovich leading the way. Laetitia Garriott joint the founding team in 2014.
SOURCE - Escape Dynamics, Space News, Youtube