The advanced technology company “Escape Dynamics”, headquarted in Colorado (US), announced successful tests of their thruster powered by beamed high power microwave energy, with performance greatly surpassing the limit of chemical combustion rockets.
The difference between NASA’s space shuttle program and Escape Dynamic, is the technology for spacecraft’s external propulsion. The 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 spaceplane during the ascent and acceleration to orbital velocity.
“With this technology, we can uniquely bring to market reusable, single-stage-to-orbit spaceplanes, and aircraft-like operations to orbit, and significantly decrease the cost of access to space for payloads up to 200 kg”, said Laetitia Garriott, President of Escape Dynamics.
For over half a century, space access has been solely dependent upon large, expendable chemical rockets, which Escape Dynamics plans to change by using microwave energy delivered wirelessly to a heat exchanger on the spaceplane during the entire ascent via a phased array of microwave antennas located on the ground. Instead of chemical combustion, Escape Dynamics’ spaceplane will be propelled by ejecting hydrogen, heated with the microwave energy, as it flows through the heat exchanger and will be exhausted through the nozzle creating thrust. After the spaceplane reaches orbit and deploys the payload, it will glide back to the launch pad, refuel, and will be ready for its next flight.
Enthusiasm for the game-changing nature of this development echoes across the commercial space industry. Will Marshall, CEO of Planet Labs, commented: “Currently, small satellite payloads cost approx. $25,000-50,000 per kilo to launch, and must share a launcher with other satellites. I’m very supportive of efforts to create lower cost and more regular access to space. Escape Dynamics is pursuing a radical technology — one I fundamentally think is a good idea — which could massively reduce the costs for small satellite payloads.”
Escape Dynamics’ recent tests demonstrated a full sequence of operation of an externally-powered propulsion system. Energy was drawn from the electric grid, converted into microwaves using a gyrotron, guided through a system of beam shaping mirrors, and beamed from an antenna to a thruster. Conversion of the microwave energy into thrust was performed using a thermal thruster with a highly efficient microwave-absorbing heat exchanger. The heat exchanger was designed to capture more than 90% of the incoming microwave energy and heat the propellant flowing through it towards the nozzle.