There is an image that is going around the world. A shot halfway between documentary and surreal, which portrays a familiar yet alien object. An 11 meter long piece of rocket, suspended in the cosmic darkness 400 km from Earth. This is not a photomontage or a digital rendering, but an authentic photograph, captured by a satellite at a record distance of just 50 meters. An unprecedented undertaking, which marks a crucial step forward in the fight against one of the most pressing problems of the space age: orbital debris.
Yes, because that strange metal scrap floating in the frame is nothing more than a fragment of the thousands of tons of garbage that crowd the space around our planet. A real "island of debris", orbital equivalent than the one made of plastic floating in the Pacific Ocean. Debris from old missions, decommissioned satellites, loose fragments traveling very fast, representing a growing threat to space vehicles and infrastructures. And it is precisely to study this cosmic rubbish closely that it was launched ADRAS-J, the "sweeper" satellite protagonist of this historic photo. A first, courageous step towards the future reclamation of Earth's orbit. Let's see how.
Space debris, invisible threat
Many of you already know that above our heads, while we wander unaware between home and office, there is a real landfill of space debris. Earth orbit, especially low orbit (LEO, Low Earth Orbit, up to 2000 km altitude), is crowded with a multitude of abandoned objects. However, many are unaware of the extent of this material. An inventory of waste that NASA estimates to be around 6000 tons, for a total of over 100 million fragments larger than one millimetre.
The problem is that all this debris, even the smallest, moves at crazy speeds, up to 28.000 km/h. At those speeds, even a bolt or a chip of paint can turn into lethal projectiles for operational space vehicles, such as the International Space Station or the increasingly numerous satellites on which our telecommunications depend. The weather. GPS navigation. Not to mention the growing risk of cascading collisions, with debris colliding and generating more debris in a potentially catastrophic avalanche effect.
In short, space debris is a real sword of Damocles on the sustainability of human activities in space. A problem that requires global cooperation and innovative solutions: a bit like that of astroscale, with its pioneering ADRAS-J program.
Astroscale, the street cleaners of space
Founded in 2013 in Tokyo, Astroscale is one of the world's leading companies in the development of space debris removal technologies. Its stated mission is to “ensure the safety and long-term sustainability of space activities,” through monitoring, inspection and active removal of orbital waste services.
Its ADRAS-J (Active Debris Removal by Astroscale-Japan) project was selected by the Japanese space agency JAXA for a commercial-scale debris removal demonstration (CRD2, Commercial Removal of Debris Demonstration). The objective of the mission? Test key technologies for approaching, inspecting and characterizing space debris, in view of future capture and removal operations.
The designated target was an H-2A upper stage, a Japanese rocket component about 11 meters long, which has been in orbit since 2009 after completing its task of launching an Earth observation satellite. An emblematic wreckage, perfect for testing the capabilities of the ADRAS-J satellite.
But how does a mission of this type take place in practice?
Anatomy of a space encounter
First you need to precisely locate and track the target debris, using radar and telemetry data. A real space hunt which, in the case of ADRAS-J, began last February. Once the target orbit was defined, the sweeper satellite began the approach phase, guided by sophisticated autonomous navigation algorithms and data from a network of ground stations.
As the distance decreased, from the initial approximately 10 km down to a few hundred meters, on-board sensors, such as high-resolution cameras and infrared vision systems, came into play. Electronic eyes indispensable for the final, delicate rendezvous.
Finally, on April 9th, the long-awaited meeting: ADRAS-J visually "hooked" the H-2A debris from a safe distance, confirming it could track and follow it in a stable manner. An already remarkable result in itself, which paved the way for the last, exciting phase of the mission: the close inspection.
In the following weeks, in fact, the satellite progressively approached the wreckage, until it reached a record distance of around 50 meters in mid-May. It was at that point that the historic image that went around the world was taken: the first close-up portrait of one of the space debris plaguing Earth's orbit, captured from an unprecedented perspective.
A shot which, in its raw beauty, perfectly summarizes the meaning of Astroscale's undertaking: shedding light on a problem invisible to most, but increasingly pressing for the future of human activities in space. And demonstrate that cutting-edge technological solutions, such as garbage satellites, can make a difference in the fight against orbital pollution.
One small step for a satellite etc
Of course, that of ADRAS-J is only a first, partial victory. Getting up close and photographing space debris is one thing, capturing and removing it is another story. For that, even more complex and ambitious missions will be needed, equipped with robotic arms or nets capable of physically hooking the wreckage and dragging it towards a controlled atmospheric re-entry.
But let's not underestimate the importance of this first, historic step. The images and data collected by ADRAS-J, in fact, will be fundamental to better understand the challenge that awaits us. To study the conditions and dynamics of debris, to refine navigation models and capture strategies. In other words, to lay the foundations for a future in which space will be a cleaner, safer and more sustainable place for everyone.
A future in which increasingly advanced scavenger satellites will patrol the Earth's orbit, ready to intervene as cosmic guardian angels to remove the dangers and waste left by previous generations. A bit like our urban garbage services do here on Earth.
With a fundamental difference, however: that while the streets and squares of our cities are an asset that belongs to citizens, space is a common asset of all humanity. A legacy to be preserved and passed on to future generations. Help us keep the orbit clean!