Spaceflight, even with SpaceX's commercial launches to the International Space Station (ISS), is still expensive and resource-intensive. Larger and heavier rockets must dedicate large amounts of their storage space for fuel supplies.One of the many research teams that are studying alternative forms of propulsion proposes a novel way to power rockets: blast them from the ground with a microwave beam.According to their study published in the Journal of Spacecraft and Rockets last month, the team was made up of engineers from Japan's University of Tsukuba Nagoya University. They were able to power a small quadrotor drone that flew freely using a microwave while it was in flight with the powerful microwave.According to a Tsukuba press statement, the researchers explained that they didn't know how feasible this idea was before their experiment. After much experimentation, the researchers believe that microwave beams could be used to lift an aircraft and possibly launch rockets into orbit.AdvertisementAdvertisementAlthough the team was not the first to try powering a spacecraft using a microwave beam, it was one of their most successful. It was however the first time this experiment had been attempted in decades. This meant that they could use stronger beams and better technology to track the spacecraft, which allowed them to fly where others failed.In the press release, Kohei Shimamura, a Tsukuba engineer, stated that we used a sophisticated beam tracking system to ensure that the drone got as much microwave power as possible. To increase transmission efficiency, we also carefully tuned the phase of microwaves with an analog phase shifter, which was synchronized to GPS units.Although this is still early days for the unique propulsion technique, the team was able to transfer enough energy into the drone to keep the drone in flight.It will still be some time before the next NASA mission is launched by a microwave beam. According to the study, 0.43 percent of the total energy efficiency of this experiment was due to energy lost through conversion into the beam or by the drone capturing and converting it to electric power.AdvertisementAdvertisementThis is a dismal result in the overall scheme of things. It is still shockingly higher than the 0.1% energy efficiency that the same group measured using a fixed-position drone in an earlier experiment. But, hey, they are getting there.These results indicate that further work is required to improve transmission efficiency and evaluate the feasibility this propulsion approach for rockets, spacecraft and aircraft. Shimamura stated.READ MORE: Research on microwave-powered rocket propulsion [University of Tsukuba]Read more about unusual spacecraft: US Tests a Space Propulsion System that Does Not Use FuelAdvertisementAdvertisement
