🛰️ For the first time, a spacecraft will visit multiple space wrecks

It is now possible to closely inspect defunct satellites, a technical feat that paves the way for a better understanding of their failures. Previously, operators had to rely on ground-based observations to guess what had happened.

Thus, the Japanese company Astroscale has unveiled an unprecedented mission: the ISSA-J1 spacecraft, weighing 650 kilograms (about 1,433 lb), is to fly over two retired Japanese satellites in 2027. Its goal is to carry out detailed visual inspections, using thrusters and high-precision imaging systems.


The targets are two large satellites: ALOS, launched in 2006, the size of a bus and weighing 4 tonnes (about 8,800 lb), which lost power in 2011; and ADEOS-II, launched in 2002, slightly lighter (3.7 tonnes, about 8,160 lb) but placed higher. Their common point? They died in orbit, victims of failures that we wish to elucidate.

To do this, the approach will be in several stages: ISSA-J1 will first approach ALOS, starting its observations from a distance before moving closer. Once the inspection is complete, it will change orbit to join ADEOS-II and repeat the same ballet. This sequence demonstrates a new capability: visiting multiple clients on different orbits in a single mission.

Thanks to these inspections, we obtain a valuable look at the condition of satellites, much more precise than what ground-based telescopes can provide. Understanding why a spacecraft stopped working helps design more robust devices in the future and prepare for possible on-orbit repairs.

Astroscale doesn't stop there: the company is also preparing the ELSA-M mission, a debris removal demonstrator, in partnership with the German launcher Isar Aerospace. These efforts are part of a broader Japanese program to strengthen knowledge of the space environment and on-orbit services.

Space debris: a growing problem

Earth's orbit is cluttered with defunct satellites, rocket stages, and various fragments. It is estimated that there are more than 30,000 debris pieces larger than 10 centimeters (about 4 inches). These objects travel at several kilometers per second and pose a danger to active satellites, space stations, and crewed missions.

A collision with debris can destroy a satellite or create a cascade of fragments, worsening the situation. This is called the Kessler syndrome. To limit this risk, international initiatives recommend deorbiting satellites at the end of their life or placing them on a graveyard orbit.

Inspection missions like ISSA-J1 help to better understand the state of debris and identify causes of failures. This data is essential for designing more resilient satellites and for planning orbital cleanup operations in the future.

On-orbit services: a new frontier

Operations such as inspection, repair, refueling, or removal of satellites were until now reserved for crewed missions like those to the International Space Station. But private companies like Astroscale are developing autonomous spacecraft capable of performing these tasks robotically.

Inspection is the first step. Knowing what is wrong makes it possible to decide whether the satellite's life can be extended, for example by refueling it or replacing a faulty component. These services could become a real market in the years to come.

The technical challenges are numerous: approaching an object not designed to be visited, maneuvering with precision, and transmitting data. Missions like ISSA-J1 open the way to a new era where satellites will no longer be disposable items, but assets that can be maintained.