This is important for space solar energy, which has greater energy production potential than stationary solar panels on Earth. Stationary solar panels are not the only way to generate clean solar energy. In a unique experiment conducted last year, researchers from various fields successfully used orbiting satellites to collect solar energy and transmit it to Earth. The results of the experiment are detailed in a new article published on the arXiv portal. The team behind this achievement was from the California Institute of Technology (Caltech)’s Space Solar Power Project (SSPP for short). They conducted the experiment last year in collaboration with Indie Semiconductor, Inc., NASA’s Jet Propulsion Laboratory (JPL), Amazon Web Services, and Caltech spinoff startup GuRu Wireless. The collaborative effort resulted in a prototype called the Space Solar Power Demonstrator (SSPD-1). The prototype will eventually be used for three experimental technologies, including space solar power generation. Today, we already use solar energy and solar panels to generate electricity on Earth, but even the most advanced solar panels have drawbacks. Cloudy or rainy days can reduce solar panel performance by up to 25%, and fixed panels can’t generate electricity at night for obvious reasons. On-orbit solar panels, on the other hand, can operate at night as long as they are rotated to expose them to the sun’s rays. Scientists needed to find a reliable way to transmit energy collected in space to Earth and use it to power homes, businesses, public resources, and more. This is his idea of MAPLE (Microwave Array for Low Earth Orbit Energy Transfer Experiment), one of his three main technologies for SSPD-1. Based on a 6U CubeSat, MAPLE harnesses solar energy collected by the SSPD-1 solar array and converts it into radio frequency (RF) energy using a rectifier antenna array. A pair of custom-made 16-channel silicon radio frequency ICs (RFICs) then synthesizes a beam of radio frequency energy that can be transmitted to Earth. On the roof of Caltech’s Moore lab, special equipment has been installed to track MAPLE’s position, and a high-frequency receiver receives the incoming energy and converts it into direct current. On January 3, 2023, a team of SSPP scientists successfully launched his SPPD-1 prototype into low Earth orbit (LEO) on his SpaceX Falcon 9 rocket. Just two months later, his SSPP team at Caltech began experimenting with his MAPLE power transfer hardware. In his preprint SSPP paper, which is currently under peer review, he reports a slight performance drop at the end of each experiment, but the experiment can be described as successful throughout the 10-month period. Ultimately, the SSPP team hopes to create a “constellation” of satellites like his SPPD-1 that can transmit enough energy to power 10,000 homes. Of course, we still have a long way to go. MAPLE was able to capture 175 to 251 mW for long periods in space, but only 1 mW reached the Caltech ground station. However, the purpose of the SSPP experiment was not to supplement the power grid, but rather to prove the feasibility of producing solar energy in space.