Space Debris Removal: Astroscale Inspection Mission Launches

Earth’s orbit is becoming dangerously crowded. With thousands of defunct satellites and rocket bodies circling the planet, the risk of catastrophic collisions increases every year. To address this looming crisis, private company Astroscale has successfully launched a groundbreaking mission to inspect a large piece of space junk. This marks a critical step toward developing the technology needed to clean up low Earth orbit.

The Mission: ADRAS-J

The mission is officially titled “Active Debris Removal by Astroscale-Japan” or ADRAS-J. It launched on February 18, 2024, aboard a Rocket Lab Electron rocket from the Mahia Peninsula in New Zealand. This mission is unique because it is not just launching a satellite; it is hunting down a specific, uncontrolled object that has been drifting in space for over a decade.

The primary goal of ADRAS-J is to rendezvous with a discarded Japanese rocket upper stage. The spacecraft must safely approach the object, characterize its movement, and inspect its condition. This data is vital for future missions that will attempt to grab and deorbit such objects.

The Target: A Bus-Sized Rocket Body

The target for this mission is the upper stage of an H-IIA rocket (specifically flight number 15). This rocket body was originally launched by the Japan Aerospace Exploration Agency (JAXA) in 2009 to deploy the GOSAT earth observation satellite.

Here are the specific details of the debris:

  • Length: Approximately 11 meters (36 feet).
  • Diameter: 4 meters (13 feet).
  • Mass: About 3 tons.
  • Orbit: Low Earth Orbit (LEO), roughly 600 kilometers above Earth.

Unlike functioning satellites, this rocket stage is “non-cooperative.” It does not emit GPS signals, it does not have reflectors for laser ranging, and it does not communicate with ground stations. It is a silent, tumbling cylinder of metal moving at 17,500 miles per hour.

Why This Mission is Difficult

Approaching a non-cooperative object is one of the hardest challenges in orbital mechanics. When a spacecraft docks with the International Space Station (ISS), the station provides data on its position, speed, and orientation. The H-IIA rocket body provides nothing.

ADRAS-J must rely entirely on its own sensors to find the object and approach it without crashing. The satellite uses a suite of cameras and LiDAR (Light Detection and Ranging) sensors to determine the distance and movement of the target. This technology, known as RPO (Rendezvous and Proximity Operations), allows the satellite to perform a complex orbital dance.

The operations follow a strict safety protocol:

  1. Far Approach: The satellite moves to within a few hundred kilometers using ground-based tracking data.
  2. Close Approach: Using onboard visual sensors, it closes the distance to a few hundred meters.
  3. Proximity Operations: The satellite moves within tens of meters, matching the speed and rotation of the rocket body.
  4. Fly-Around: The spacecraft circles the debris to take high-resolution images to assess structural integrity and spin rate.

In April 2024, Astroscale released the first images taken by ADRAS-J from a distance of several hundred meters, confirming the technology works as intended.

The JAXA Partnership and Future Goals

This mission is part of a larger initiative by JAXA called the Commercial Removal of Debris Demonstration (CRD2). The Japanese space agency realized that government agencies alone cannot solve the debris problem; they need commercial innovation.

The CRD2 program is divided into two phases:

  • Phase I (Current): Astroscale’s ADRAS-J mission. The objective is strictly inspection and data gathering. They need to know if the rocket body is tumbling wildly or spinning slowly before they can design a capture mechanism.
  • Phase II (Future): This phase involves actually capturing the debris and removing it from orbit. Astroscale has also been selected as a partner for this phase, where the goal will be to use a robotic arm or similar mechanism to grab the H-IIA stage and drag it into the atmosphere to burn up.

The Growing Threat of Space Junk

The urgency for missions like ADRAS-J stems from the “Kessler Syndrome,” a theoretical scenario proposed by NASA scientist Donald Kessler in 1978. The theory suggests that if the density of objects in low Earth orbit becomes high enough, collisions between objects could cause a cascade. Each collision creates smaller debris, which causes more collisions, eventually rendering specific orbits unusable for generations.

There are currently over 36,500 pieces of space debris larger than 10 centimeters tracked by space surveillance networks. However, there are millions of smaller pieces that are untrackable but still lethal to satellites and astronauts.

Large objects like the H-IIA rocket body are priority targets. While they are not currently hitting anything, they act as ticking time bombs. If two 3-ton rocket bodies were to collide, they would create thousands of new fragments that would threaten active satellites like Starlink or the ISS.

Competition and Regulations

Astroscale is a leader in this field, but they are not alone. The European Space Agency (ESA) has commissioned the ClearSpace-1 mission, scheduled for launch around 2026. ClearSpace aims to remove a VESPA payload adapter left in orbit by a Vega rocket.

Regulations are also catching up to the technology. In late 2023, the U.S. Federal Communications Commission (FCC) issued a new rule requiring operators to deorbit LEO satellites within five years of mission completion. Previously, the guideline was 25 years. This regulatory pressure creates a market for companies like Astroscale. Satellite operators who fail to deorbit their spacecraft due to malfunction may eventually need to pay “tow truck” services to remove them to avoid fines or licensing issues.

ADRAS-J proves that the “tow truck” is no longer science fiction. It is currently in orbit, flying in formation with a dead rocket, gathering the data needed to keep space open for future exploration.

Frequently Asked Questions

What is the main goal of the ADRAS-J mission? The primary goal is to safely approach, characterize, and photograph a large, discarded Japanese rocket stage to prove that “Rendezvous and Proximity Operations” (RPO) can be performed on non-cooperative space debris.

Will ADRAS-J remove the debris? No. This specific mission (Phase I) is for inspection only. It will not attempt to capture or deorbit the rocket body. Removal is planned for Phase II of the JAXA program.

How close will the satellite get to the rocket body? ADRAS-J is designed to approach within a few meters of the target to capture detailed images and data regarding the rocket’s spin and physical condition.

Who is funding this mission? The mission is funded through a contract with the Japan Aerospace Exploration Agency (JAXA) as part of their Commercial Removal of Debris Demonstration (CRD2) program.

What happens to the ADRAS-J satellite after the mission? Once the mission objectives are complete, Astroscale will likely deorbit the ADRAS-J satellite safely, ensuring it does not become space debris itself.