The external propulsion system that Escape Dyamics proposes uses a phased array of antennas on Earth to send microwaves at 92 GHz to a space-plane’s microwave-absorbing heat exchanger. This would heat up hydrogen, which then bursts out of a nozzle system to create thrust. Some important details still need to be worked out before launching any microwave-powered trips to space. Engineers need to build powerful enough antenna array, ensure that the microwaves stay on target, and address any potential safety concerns about firing microwaves into space.
Escape Dynamics joins private companies such as Virgin Galactic and SpaceX in the quest for innovative spacecraft that can provide affordable trips to space and back. If external propulsion technology works, it will have many advantages over current systems. In traditional launch systems, fuel takes up as much as 90 percent of the weight. Reducing this weight would leave more room for useful payloads and would drastically reduce the cost per launch, which could lead to on demand flights for small satellites. Certainly, launches would be safer, without the risk of explosion that comes along with combustion-based systems. One of the biggest benefits of the proposed microwave-based system is that space launch vehicles would become reusable. Finally, the current design is powered with electricity from the grid through a battery storage system, but future iterations of the system could use renewable sources of energy.
