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It could be one small step for space junk, one giant leap for commercial space operations.

The European Space Agency signed an €86 million contract with a team led by Swiss start-up ClearSpace SAin November, talking to reporters on Tuesday about what could be the first space mission to remove an item of debris from orbit, and one that could potentially push the commercial space trash removal market forward. And folks, the proposed spacecraft has four robotic tentacles.

Space debris has long become a colossal problem, not one you can personally see clogging up your streets and drains outside, but one that could have serious impact on future space endeavours — particularly if you're in the business of launching say, thousands of satellites.

It's been 60 years since the Space Race started, and more than 5,550 rocket launches from Earth have left approximately 23,000 tracked objects remaining in space, not to mention the millions of bits and pieces floating around low Earth orbit known as "space junk." About 9,600 satellites have been placed into Earth's orbit to date, with about 5,500 still in space, and just 2,300 of those are functioning.

This only stands to increase, with today's space industry averaging 100 launches a year. Add to this the rising popularity of satellite "mega-constellations" as a means for worldwide telecommunications coverage, consisting of hundreds, even thousands of objects — Elon Musk wants to send a total of 42,000 satellites into orbit for SpaceX's Starlink project, aiming to provide high speed internet to the globe.

Problems arise when larger objects in orbit collide in space, causing fast-moving, smaller fragments of space debris to break off, creating a space junkyard that can cause all kinds of hazards at speed, especially for active spacecrafts. The 2009 collision between active commercial satellite Iridium 33 and inactive military satellite Kosmos-2251 has become the prime example of this, but even as recently as September last year, the European Space Agency's Aeolus satellite had to fire its thrusters to avoid colliding with one of Musk's Starlink satellites.

It's a problem with exponential growth potential, most notably due to a phenomenon known as "Kessler Syndrome," a term coined in 1978 by astrophysicist Don Kessler, a former senior scientist for orbital debris research at NASA, which describes the idea that one collision could result in several more, like falling dominos.

"The more populated the orbits around us get, the higher probability of collisions," Rolf Densing, ESA director of operations told reporters on Tuesday. "This has happened in the past, and unfortunately, I'm quite sure that this will happen in the future as well."

Space junk clean-up is no easy task — you can't just vacuum it up, sweep it under some space rug, or pluck it out like a piece of lint on a cardigan. People have tried, some more successfully than others. NASA has been studying this since the '70s. But ClearSpace's contract with the ESA, potentially the first space mission to remove an item of debris from orbit, could be a significant moment for space trash removal if the mission is successful.

The ClearSpace-1, a 500-kilogram spacecraft equipped with four robotic tentacles, is locked in to launch in 2025. Funded by ESA and backed by enterprises in several European countries including Switzerland, the Czech Republic, Germany, Sweden, Poland, the United Kingdom, Portugal, and Romania, ClearSpace's project was the winning idea after ESA issued a callout in 2019 for experts to pitch a space debris removal solution.

For its first mission, the ClearSpace-1 will aim to capture the upper part of an ESA-owned craft known as VESPA (Vega Secondary Payload Adapter), a 112-kilogram object about the size of a small satellite that was launched in 2013 and eventually left in "gradual disposal" orbit at an altitude of about 800 kilometres by 660 kilometres.

"First of all, it's a simple structure," said Muriel Richard-Noca, chief engineer of ClearSpace SA. "So, the type of small satellites; a bit bigger than a washing machine. It has basically the size and the mass of our targeted market."

ClearSpace's idea is to launch its spacecraft into orbit at a lower, 500-kilometre altitude below the VESPA, for commissioning and tests before being raised to the target's orbit.

To capture the object, ClearSpace-1 will use robotic arm technology developed with ESA to capture the VESPA, in what looks like something out of James Bond's You Only Live Twice or the crane game down at the arcade.

Just look at this incredible demonstration of the proposed capture process:

These tentacles weren't the only possibility for the ClearSpace team; it was a fiercely debated toss-up between this option and a net — for one, the University of Surrey successfully deployed a net in 2018 which captured a piece of debris that was orbiting around Earth. It was a little more classic than the space harpoon method the same university deployed in 2019, which nonetheless worked. After capture, debris removal is the next step for these tests, something ClearSpace hopes to be the first ever to do.

The net option, Richard-Noca pointed out, would actually hinder their mission rather than help. "If you throw a net and the net misses your target, you would have to have a second net and try again, but then you will have to capture not only the net that you launched, but also the target. So it becomes complicated," she said. "Here with the tentacle, if we start going into the capture, we see there is a problem, we can go back, reverse the whole procedure. This system gives us the flexibility that we need for this first time demonstration."

During the capture sequence, ESA will supervise operations to make sure ClearSpaceSA operates within safe procedures, but the start-up will be taking the helm. The ClearSpace-1 will use new image processing techniques to reconstruct the target's movement for study in future missions if the VESPA mission is successful.

Then, the ClearSpace-1 will perform a controlled atmospheric reentry with the space trash, and both will burn up on re-entry. Essentially, the vessel will analyse and grab the debris, then sacrifice itself.

Already existing space debris varies in size and weight, with more inevitably on the way with the launch of mega constellations. ClearSpace and ESA intend to focus on the larger objects first, like the VESPA, and then move onto the smaller ones, as the larger objects (per Kessler's Syndrome) tend to be those sources of new fragments prompted by collisions.

"We are looking at options to remove smaller objects, however, we must be clear that the priority are the large ones," said Holger Krag, head of ESA’s space safety programme. "These are the source of the small ones. It is extremely effective to go for these ones first."

Space debris isn't just an inconvenience, it's burning a hole in the pocket of space operations. Using data from ESA's Space Debris Office, the Organisation for Economic Co-operation and Development (OECD) in April published its first report on the economic cost of space debris, and found that for satellites in orbit, costs related to space debris — added surveillance and tracking measures on board the satellites, and moving satellites out of the way — could amount to 5–10 percent of the total mission costs, which could be hundreds of millions of dollars. The report said this could be even higher for missions in low Earth orbits.

So, while that €86 million contract seems outstandingly expensive, ClearSpace sees this as an opportunity to reduce long-term damage control costs for satellite operators and the countries that manage them. But if successful, the team says the price for the service will come down a lot after the first demonstration mission.

"Our goal is to build up a commercial service," explained Luc Piguet, CEO of ClearSpace SA. "We will target to perform steadily more ambitious removal and servicing during the follow-up missions. The idea is to go to larger objects, but mostly to go to multi-object removal, to be able to essentially bring down the cost of space operations for that kind of operation." ClearSpace's technology could also be potentially used in different applications during future missions, like refuelling and servicing satellites in order to extend their life in orbit — a market Piguet says is very little served.

In terms of the companies gearing up to send thousands of new objects into space, ESA director of operations Densing noted that operators of mega constellations like SpaceX would probably be interested in keeping their orbits free of defunct spacecraft — and agencies will want to keep their spacecrafts free of this too. "Who wants to go back to the customer, to the owner of the spacecraft and explain to them that they have crashed a spacecraft [thanks to] a piece of space debris? You're doing everything in your power to avoid this," he said. Plus, if a piece doesn't damage a satellite, simply moving it out of the way in an avoidance manoeuvre can lead to lost data while the satellite is busy dodging the debris. "We are getting plenty of collision warnings — there's more than 100 per day. Then we analyse them and we have to fly a collision avoidance manoeuvre about every two weeks on a fleet of some 20 spacecraft."

ClearSpace isn't the only company working on space debris removal in the world — for one, Japanese company Astroscale plans to launch the first phase of its own technology by April 2023.

Piguet said that ClearSpace has been talking with satellite constellation companies like OneWeb and Iridium during their development process to discuss the most pressing problems of space debris from a commercial perspective. "What we could see is that there's a real concern around this subject, especially for operators that are operating beyond 600 kilometres altitude," he said. "To give you one example, OneWeb, if one of their satellites fails, it will remain in orbit for more than 1000 years. So it's not so much the question of what is the cost of one single unit, but what is the cost over time of the risk of keeping those objects up there."

ESA director general Jan Wörner sees space debris removal as "market of the future," as the need for it becomes imperative, and advocated for three potential requirements when it comes to satellite companies launching more of their own into space.

"In future, a satellite provider should at least have one of the following three conditions fulfilled," said Wörner. "Either the system has an automatic de-orbiting system on board, number one. Or number two, the company has a contract with another contract saying, 'OK, in case your satellite is not working, we will bring it down.' So for instance, ClearSpace. Or number three, they give a deposit to an agency, and then in case something happens, the agency can go to ClearSpace or whoever and ask the company to bring it down. I think there are a lot of business models."

It remains to be seen just how marketable space trash removal services are going to be — instead of coughing up for a rather expensive taxi ride, satellite companies may agree, like Wörner said, to make sure the satellite will de-orbit and incinerate in the atmosphere in the future. That being said, the space trash problem isn't getting any smaller, so solutions like ClearSpace's are exciting.

Might just be time to jump into the business of space junk removal, before it gets crowded.

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