Astroscale Japan Catches Up To Space Junk, Will De-Orbit It

In his classic book “The Hitchhiker’s Guide To The Galaxy” writer Douglas Adams once said that “Space is big. You just won’t believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it’s a long way down the road to the chemist’s, but that’s just peanuts to space.”

Adams is right, of course. Space is infinitely huge, but at the same time, near-Earth orbit is an increasingly crowded place. As of March 7, 2024, 9,494 active satellites were orbiting Earth, and there are another 3,300 inactive satellites.

There Is A Lot More Space Junk Than Active Spacecraft In Orbit

Those numbers pale in comparison to so-called “space junk”—debris or machinery left by humans in space, including spent rocket stages, pieces discarded by rockets or people still in orbit, and the detritus from previous satellite collisions. Even pieces of paint that have flaked off of spacecraft count because despite their tiny size, they can pack an incredible punch should they hit another object in orbit.

In total, the 6,300 successful rocket launches since 1957 have delivered 14,450 satellites into Earth’s orbit. Over that same period, more than 630 explosions, collisions, or other unplanned events have caused objects to split apart or fragment, creating a huge amount of debris in orbit.

To be fair, much of that debris has re-entered Earth’s atmosphere and burned up, but a lot of it still up there. NASA estimates that an active satellite in low Earth orbit (LEO) will collide with a piece of debris larger than 1 cm every five to six years. Operational spacecraft are routinely struck by very small, sub-millimeter-sized orbital debris with little or no effect.

ISS And Space Junk

For larger pieces of materials, many spacecraft like ISS change their orbital position to avoid an accidental collision. Even then, there have been incidents where astronauts and cosmonauts have been ordered into their capsules to “shelter in place” because of the potential for a catastrophic collision.

On November 15, 2021, seven astronauts were forced to take shelter in their transport spacecraft when the station passed close to orbital debris. The astronauts spent two hours in the capsules and had to close and reopen hatches to the station’s labs every 1.5 hours as they passed near or through the debris.

How Much Space Junk Is Up There?

As of January 2022, NASA estimates that there are more than 25,000 objects larger than 10 centimeters in orbit around Earth, and millions of smaller pieces. This includes:

• 1–10 centimeters: Approximately 500,000 particles
• 1–1 millimeter: More than 100 million particles
• Smaller than 1 centimeter: More than 128 million pieces

Over two hundred and twenty million pieces of space junk is quite a huge number, and that changes the odds of any one of them hitting an active — or worse, crewed — spacecraft at any given time. Suddenly, “mind-bogglingly big” becomes a simple matter of time.

How Do We Keep Up With It All?

The US Department of Defense operates the Space Surveillance Network (SSN) to track objects in space. The SSN uses radar and optical sensors at different sites worldwide to detect and track satellites and space junk.

According to the Aerospace Corporation, “These sensors observe and track objects that are larger than a softball in low Earth orbits and basketball-sized objects, or larger, in higher, geosynchronous orbits. The sensors can determine which orbit the objects are in and that information is used to predict close approaches, reentries, and the probability of a collision.”

Risks Of Space Junk

Can We Fix The Problem?

According to Aerospace Corporation, “We can’t just vacuum or sweep it up into a space garbage truck. To remove space debris, particularly the large and more dangerous objects, we have to get close to it and maintain the same speed as each object. We then, somehow, must attach to it, and move it into a lower orbit or reenter it directly into the ocean. “

Enter Astroscale

Astroscale Japan, a Tokyo-based aerospace company, was selected by JAXA for Phase I of its Commercial Removal of Debris Demonstration (CRD2) program. According to the company, its ADRAS-J spacecraft is “a groundbreaking mission as the world’s first attempt to safely approach, characterize, and survey the state of an existing piece of large debris through Rendezvous and Proximity Operations (RPO).”

Astroscale reported that they have achieved a critical milestone in the ADRAS-J mission, when they “approached the client within several hundred meters.” That client was a piece of large space junk — a spent second stage left in orbit after a JAXA launch.

Next up, according to Astroscale, is the next phase of for the CRD2 program. They say in a press release that “The CRD2 program aims to remove an unprepared Japanese upper stage rocket body, thereby addressing the increasingly critical issue of space debris. Unprepared objects in orbit pose an additional challenge as they have not been prepared with any technologies that enable docking or potential servicing or removal.”

Astroscale added “We are deeply honored to have been selected as the commercial partner of the next phase of this trailblazing program,” said Eddie Kato, President & Managing Director of Astroscale Japan. “Having demonstrated several key capabilities during the ongoing Phase I mission, we are eager to demonstrate our ability to address the next challenge: the removal and deorbiting of large debris. This next phase holds significance in addressing the space debris issue and laying the foundation for a sustainable environment for future generations. We extend our heartfelt gratitude to JAXA for entrusting us with this responsibility.”

If successful, they will demonstrate the first removal of a large piece of space junk, making Earth orbit safer for everything and everyone who travels there.