More people than ever are joining the private space race, developing new ways to loft craft into the night sky. But the Colorado space startup Escape Dynamics has an unusual plan to achieve that goal, which will use beams of microwaves to power a rocket into space.
Late last week, Escape Dynamics announced that it has successfully tested prototypes of its new spaceship engine. But unlike normal rockets, their engines use high-power microwave sources to power electromagnetic motors aboard the craft. The idea is that the removal of some of the on-board power systems would allow for craft that could make it into space in one piece, without jettisoning components — making them fully and rapidly reusable.
In reality, Escape Dynamics would need to create a large-scale energy storage system, charged from the grid or renewable sources, which would be used to drive its microwave system. Then, a series of phased array microwave transmitters would be used to focus beams of microwaves at the underbelly of the craft, where they'd power a heat exchanger that ignites on-board hydrogen to supply the rocket with energy. As the craft takes off, the microwaves would track the ship, providing continued energy as it moves through the sky.
It's a bold aim. But tests of prototypes devices here on Earth suggest it's plausible. Engine efficiency for space craft can be measured in units of Specific Impulse, measured in seconds, with normal chemical rockets topping out at about 460 seconds. The new Escape Dynamics system has shown to achieve 500 seconds, and the company claims that if it swapped out the prototype helium fuel source system for hydrogen that could easily become 600 seconds. That could perhaps be enough to loft a craft into orbit with just one fuel stage.
There's still a little way to go though. Next, the team behind the technology plans to carry out open-air tests of the set-up in the desert, before moving on to setting up a repeatable system to power drones using the technology. Only then will Escape Dynamics try to put craft into space using the technique — first sending them into space and, later, properly into orbit. There's a lot to be done, then, but the company reckons that it payloads of over 1000kg into orbit by 2025.