The US Air Force Research Laboratory and Northrop Grumman have converted solar energy into radio frequency waves using sandwich tiles. This is the first step in creating a system for transmitting energy from space to terrestrial military bases, in the future it is planned to assemble more powerful composite panels from such tiles.
In 2018, the US Air Force Research Laboratory signed a contract with Northrop Grumman for research and development of equipment for wireless transmission of energy from spacecraft. This is how the SSPIDR project (Space Solar Power Incremental Demonstrations and Research, step-by-step research and demonstration of ways to transfer solar energy) appeared.
The goal of this project is to create a spacecraft with panels that will convert solar energy into radio wave radiation and transmit it to Earth, where systems for receiving this radiation will turn it into electricity. The military believes that this will help to provide energy to hard-to-reach temporary bases and outposts, where it is expensive and difficult to deliver fuel. Conventional solar panels on Earth are not suitable for this purpose — a lot of them will be needed for a military base, and it is inefficient to install them for a short period of time.
It was not specified which technologies would allow the military to transfer solar energy from space. Maybe we are talking about the microwave transmission of energy from space, the possibility of which has been considered since the seventies. As NASA found out in 1978, in order for energy at a frequency of 2.45 gigahertz to pass through the atmosphere, an apparatus with an antenna with a diameter of 1 kilometer must be placed in orbit. At the same time, it is necessary to install a ten—kilometer rectenna on the Ground - a nonlinear antenna that converts radio wave radiation into electricity.
The US Air Force Research Laboratory reported on December 21 that, together with Northrop Grumman, they managed to convert solar energy into radio frequency. To do this, a sandwich tile made of two layers was used. The first layer contains highly efficient photovoltaic cells. They collect solar energy and feed the second layer, which includes components that allow you to convert solar energy into radio frequency waves and form a beam. What exactly these components are is not disclosed.
Program manager James Winter says the next step is to build six of these tiles and integrate them into a panel that will be tested in low Earth orbit. The military plans to launch it into space in early 2025. They call this experiment Arachne.
In addition to energy from space, the military is considering other ways to supply electricity to hard-to-reach areas. For example, nuclear mobile microreactors. Earlier we wrote that the Pentagon ordered the development of their prototypes from three companies.
Vasilisa Chernyavtseva
