Space debris removal: A wheelie bin will do that

Space debris removal: A wheelie bin will do that

It’s slightly smaller than a trash can and has roughly the same purpose: to collect waste, but in space. The device is called Elsa-d, and it will depart from the Russian Baikonur launch site next week. Elsa-d was built by Astroscale, a trading company headquartered in Tokyo with offices in several countries, including Great Britain. Astroscale was founded seven years ago and provides governments and (telecom) companies with cleaning debris from their space activities (see box).

Elsa is an acronym for End of Life Services by Astroscale. The letter “d” denotes the explanation. The device shown in the picture consists of two parts. The big piece, with solar panels, is called the service. The smaller block is its client, which is the size of the moving box. These two are stuck together. But when the Elsa-d is brought into orbit with a Soyuz missile, it will release its client, a few meters away, and then catch it again.

Unexpected strangers

The Elsa-d uses a magnetic arm for this purpose, and the first test should prove it is operating in space. On a second experiment, it gets more complicated. Space debris not only hangs a few meters away and remains stationary, but flies through space on all of its axes. In the second trial, the customer will be released again, but with one click, causing unexpected crashes. In addition, it is hundreds of meters away from service.

Elsa-d must now approach his client, measure what he’s doing, and start making exactly the same spinning motions so she can grab the client again with his magnetic arm. In a third experiment, the client will be many miles from the server, and Elsa-d must prove that he can locate and then seize a specific piece of space debris orbiting Earth.

The final part of the mission is waste disposal: the servant and his client go down to Earth and are released into the atmosphere. Due to its high speed, the air resistance causes heating and the trash and its space debris are burned. If you want to get an impression of the entire Japanese mission, you can watch the animation below.

Fatal collisions with space debris

The mission that begins next week must primarily demonstrate that the technology developed to remove space debris is working. Astroscale is already working on the next step. The company was awarded a contract last month by the Japanese space agency Jaxa. Like fellow organizations in the United States (NASA) and Europe (ESA), JAXA understands that the immediate vicinity of Earth must be cleaned to avoid deadly collisions by chopping off space debris.

In the first project, Jaxa wants to remove the last stairs from a missile launched earlier. The giant, which weighs several tons on Earth, is floating in orbit around the planet. Picking it up and clearing it would be a completely different story to the Elsa-d mission. However, the missile stage is several times larger than that of the customer Elsa-d will play, it has no iron and cannot be caught with a magnetic arm.

In this case, it is likely that a robotic arm could be developed that could accommodate the obsolete portion of the missile. But this is for later. In the first part of this Japanese mission, Astroscale will launch a satellite to examine this piece of space debris closely, from a distance of several meters, and to map its immediate surroundings. It has to be done next year, after which Jaxa can think of a second stage in how to bring the Colossus into the atmosphere for cleansing.

Elsa-d must show that it is possible to capture space debris.Star image

Microzwaartekracht

Robotic arms are the technology ClearSpace also chooses. This young Swiss company originated from the Technical University of Lausanne three years ago and recently won the first contract offered in the new debris removal program for the European Space Agency (ESA).

In this first mission, ClearSpace will launch a four-armed robot from the Kourou launch site in French Guiana in 2025. It has to use it to recover part of a missile launched in 2013. The part that is now orbiting the Earth is very large; You will weigh over a hundred pounds on Earth.

In the microgravity of near space, almost nothing of this weight is left. This sounds useful, but it makes recovering space debris very complicated: a little wrong and a piece of debris can disappear from view at any moment. Or worse, it can be damaged and broken into pieces, adding to the problem of space debris. Also in this case, the debris removal machine, simply called ClearSpace-1, must first accurately find out where the piece of space debris is and how it is spinning, in order to capture the giant on a trajectory.

Swiss craftsmanship

It’s a € 100m project, and it came as a surprise that Esa awarded it a young Swiss company. Switzerland is a member of the European Space Agency, but it is not a major country in spaceflight. Why is ClearSpace Swiss start-up? “Why not?” Said founder Luc Piquet recently in an interview with Innovaud, the Swiss innovation agency. “Our country has great universities and engineers, and a long tradition of craftsmanship. Made in Switzerland people associate high quality with reliability, and this also applies to aviation technology.”

According to Japanese Nobuo Okada, founder of Astroscale, it will be a matter of preparing satellites before departure for disposal at the end of their working life. His company developed a round plate with optical and magnetic properties, which is now installed on the customer. This allows Elsa-d to find and magnetically connect the customer. This panel can be installed on any future satellite. Scrapers would help.

What a mess

Space is cool and empty, but near Earth is a landfill. More than half a million pieces of space debris orbit the Earth. A small portion of it has a natural origin: meteorites that orbit the sun like Earth and approach the planet. But most of it is human waste, ranging from small bits to entire rocket bits orbiting the Earth.

This space debris is not only a disgrace, but also a great danger. The pieces rotate around the Earth at a speed of 28,000 kilometers per hour. At these speeds, even the smallest particles of debris can cause a devastating collision with satellites orbiting Earth or, for example, with a space station.

Space organizations ESA (Europe) and NASA (US) estimate that such a collision, with the current amount of space debris, occurs once every ten years. This doesn’t look like much, given the sheer amount of space debris, but it’s a lot of space.

Waste cloud

Known collisions included in 1996 when a French satellite was damaged by the remnants of a missile – also French – launched ten years earlier, and in 2009 when a retired Russian satellite collided with a commercial American satellite, which not only meant the end of life of the latter, but a bonus On it she added about two thousand pieces of debris to the trash cloud.

Therefore, the chance of colliding with existing space debris is really great. Chaos continues to grow as humanity brings more and more equipment into space. In the first decade of this century, an average of 72 satellites were put into orbit each year. There are now more than 125 a year, ESA said, and the number will increase dramatically as new and advanced versions of the internet are built.

Indeed, the International Space Station and larger satellites sometimes have to change course somewhat to avoid hitting debris. But not all space satellites have the engines to do this.

Space organizations have developed guidelines in consultation around the world to reduce the remnants of launches and bring satellites that are no longer in orbit where they are not in their way. These guidelines are not enough. Some debris must be removed to reduce the risk. If more dangerous items are chosen, the number to be saved will be limited. The technology for this is now under development. But they are very expensive missions.

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