Japanese startup plans to vaporize space junk using ground lasers

Osaka-based startup, plans to develop a ground-based laser system to help knock out space junk (Interesting Engineering).

By Christopher McFadden,
Published by Interesting Engineering, 15 January 2024

To combat the issue of space debris, Australia’s EOS Space and Japan’s EX-Fusion will develop a laser system to remove it from Earth’s orbit.

EX-Fusion, an Osaka-based startup, plans to develop a ground-based laser system to help knock out space junk from the ground. This innovative approach, if successful, could be a valuable way of clearing up the increasingly crowded space around our homeworld.

Zapping junk with lasers

Space junk, or space debris, refers to defunct human-made objects in Earth’s orbit, like old satellites and spent rocket stages. These fragments, varying in size, pose collision risks to operational spacecraft and the International Space Station. Even debris as small as a few millimeters can create problems when it hits functioning satellites and spaceships.

As a result, the need to track and remove smaller space debris grows as space-related activities spread globally. For example, Nikkei Asia reports that a Tokyo-based startup, Astroscale Holdings, plans to launch a dedicated satellite to remove relatively large space debris. Another is Japan’s Sky Perfect JSAT, which collaborates with Riken and other partners to develop a satellite-mounted laser that redirects space debris into the Earth’s atmosphere, where it burns up.

EX-Fusion stands apart because it is taking the ground-based approach, with the startup tapping its arsenal of laser technology initially developed in pursuit of fusion power. In October, EX-Fusion signed a memorandum of understanding with EOS Space Systems, an Australian contractor with technology for detecting space debris. EX-Fusion has announced its plans to install a powerful laser system at the EOS Space Observatory near Canberra.

The initial stage of this project will involve setting up laser technology to track space debris that measures less than 4 inches (10 cm). This size of debris has been traditionally challenging to target from the ground using lasers. During the second phase, EX-Fusion and EOS Space will use laser beams fired from the surface to remove space debris.

The method involves firing the laser intermittently in the opposite direction of the debris travel to slow it down. This decrease in orbiting speed should, in theory, cause the debris to enter the Earth’s atmosphere, which will burn up. The EOS Space group currently supplies laser weapon systems to destroy drones, but high-powered lasers have other applications, too.

EOS Space’s executive vice president, James Bennett, Nikkei Asia reports, said that lasers designed to remove space debris are not the same as weapon-grade lasers. Current laser weapons often use fiber lasers to cut, weld metal, and destroy drones through continuous firing heat.

EX-Fusion’s method will, however, use diode-pumped solid-state (DPSS) lasers. These lasers are pulsed to apply force to fast-moving debris, stopping it like a brake. “The power of a laser for destroying space junk is an order of magnitude lower than for nuclear fusion, but they share technical challenges such as controlling them via special mirrors,” EX-Fusion CEO Kazuki Matsuo said.

Much work to do

EX-Fusion’s plan to shoot down space junk from the ground faces development hurdles related to precision and power. Still, it has the advantage of allowing for improvements and maintenance to be easily handled on Earth. The technology could potentially be used alongside debris removal services provided by companies such as Astroscale.

See: Original Article