Rockets typically use about 90 per cent of their fuel escaping the Earth’s atmosphere. Researchers at the University of Tsukuba in Japan believe this limitation could be overcome by wirelessly transmitting the necessary power to the rocket.
Previous analyses of this kind were carried out decades ago and mostly considered microwaves of a frequency in the low gigahertz (GHz) range. Given that the power transmission efficiency increases as the operating frequency is raised, the team behind this latest research used microwaves with a relatively high frequency (28GHz).
The team managed to get a drone weighing roughly 0.4kg to hover for 30 seconds at a height of 0.8m above the source of the microwave beam.
“We used a sophisticated beam-tracking system to ensure that the drone received as much of the microwave power as possible,” said Kohei Shimamura, lead author. “Moreover, to further increase the transmission efficiency, we carefully tuned the phase of the...