June 26, 2014
My roommate loves to go fishing. Personally, I have never seen the appeal. I mean, you go and sit out in the hot sun all day looking at a pole with a string attached to it, hoping that some fish just happens to swim by and take a solid bite of your bait. Overall, it just always felt like a waste of time to me. Of course, this opinion may have some basis on my dislike of fish overall – I find them gross – and that I never really went fishing as a kid. I did not have anyone to take me, save one or two times when my grandmother felt I was “missing out” and tried taking me, despite not having any real experience with doing it herself. While it was a good attempt, it was a far shot from anything enjoyable. Of course, if someone were to combine fishing with something that I did enjoy, like say… space, then I might gain an interest.
After decades of launches, Earth’s orbit is starting to get really cluttered with space debris. Currently, there are more than 17,000 traceable bits of space junk, all larger than a coffee cup, floating around up there. Any one of them a potential threat to future missions, as any object larger than a nut or bolt could risk catastrophic damage to satellites should they collide. The only way we have to possibly control this risk is to remove larger items such as derelict satellites and the upper stages of rockets from our orbit. Doing so will lessen the current debris cloud as well as make sure that these massive objects do not break apart or explode – a genuine risk due to leftover fuel or partially charged batteries – and create even larger debris clouds. These clouds would make traveling outside of our atmosphere even more hazardous, as any one of these objects breaking apart could risk a chain reaction of debris cloud formations.
So how do we handle this? We go spear-fishing.
The European Space Agency‘s Clean Space initiative is already working on what they are calling the e.DeOrbit mission, which is set to fly in 2021. The idea is that the satellites sophisticated sensors and autonomous control will be able to identify and lock onto a target, trap them, and reel them in using a harpoon. The initial concept of the space harpoon has already undergone initial investigations by Airbus Defense and Space in Stevenage, UK, and has already been tested in the lab. A prototype space harpoon was fired into material representing the outer full of a satellite in order to gauge if the harpoon could pierce and actual satellite, the strength needed to reel the debris in, and if doing so might generate additional fragments that might threaten the retrieval unit.
The three physical actions needed to ensure a safe and clean grasp by the harpoon are a high-energy impact into the target, being able to pierce its hull, and finally being able to reel the target in, just like with normal spear-fishing. Using computer models, this project is already investigating all three of these steps in order to make sure that the e.DeOrbit will be successful. Aside from this, there have been many other different proposed solutions. These include a thrown-net, clamping mechanisms, robotic arms, and many others. Amusingly enough, the most low-tech of these solutions have thus far yielded the most promising results.
The next step of the project for ESA is to build and test a prototype in order to adopt the harpoon and its launching mechanism for the mission. There is a great deal of work that will have to be done by 2021 in order to ensure the mission’s success.
Fishing in space. What will they think of next?
Image Credit: Airbus Defence and Space