Japan is getting ready to launch a satellite with solar panels to find out if we can send solar power from space back to Earth

Japan Space Systems are exploring the possibility of generating electricity in space using the power of the Sun, and then sending it back to Earth. But how will that work, since you can't exactly hang wires from space to the ground?

While this might sound too unreal, everything is already in place to accomplish the mission. Japan will launch "a small satellite, about 180 kilograms [400 pounds], that will transmit about 1 kilowatt of power from an altitude of 400 kilometers,” Koichi Ijichi, one of the researchers and an advisor at Japan Space Systems (JSS), told Space.com.

The JSS satellite will be equipped with a 22-square-foot (2-square-meter) solar panel to collect sunlight and charge an onboard battery. The key challenge, however, is how this stored energy will be transmitted back to Earth.

Since it's not feasible to send solar energy through wires, the satellite will convert the electricity into microwaves which will then be beamed wirelessly to specially designed receiving antennas on the ground.

Additionally, because the satellite will travel at an incredible speed of about 17,400 miles per hour (28,000 kilometers per hour—the typical speed for satellites in low Earth orbit), the receiving antenna on Earth will need to be quite large, possibly spanning several kilometers.

The concept of space-based solar power was first introduced by an American physicist in 1968. He suggested launching solar panels into orbit, about 36,000 kilometers above

Earth, to capture sunlight. The technology works by converting solar energy into microwaves, the same type of electromagnetic radiation used in microwave ovens, which are then transmitted to ground-based receiving stations for conversion into electrical energy.

Since then, things have changed. Advances in robotics, wireless transmission, and orbital logistics—especially the potential of SpaceX’s Starship rocket—are making what once seemed impossible increasingly feasible.

Japan Space Systems Project Manager Yanagawa Hiroki expressed hope for the success of the flight test scheduled for later this year, along with a series of space-based experiments set to begin next year. The project team aims to make the technology practical by 2045 at the earliest.