hey have been used to hunt down whales and now there are plans to use harpoons to hunt down space junk orbiting the Earth.
The Defence and Space division of the European aerospace company Airbus has been working on the concept for a number of years in response to the growing problem of space debris.
Currently there are about 20,000 pieces of debris, sized 10 centimetres or larger, being tracked.
Alastair Wayman, an advanced project systems engineer with Airbus, helped develop the high-tech harpoon and said it would prove “really effective at capturing space debris”.
“There’s kind of two challenges to space debris, one is capturing it and one is then actually bringing it down once you’ve captured it,” he said.
“And the harpoon is a really nice way to capture it. It really simplifies that because all we have to do is stand away from the target by a reasonable distance and fire at it.
“We don’t have to go up to it and actually get in contact with it at all.”
Trapped by our own debris
The latest space harpoon has been developed with the capability to capture one of the biggest pieces of space junk of them all — Europe’s old Envisat Earth observation platform.
Weighing in at around eight tonnes, it died suddenly in 2012 while in orbit.
The trouble with big pieces of space junk is that when they collide with each other they can smash apart and become thousands of new pieces of space junk, each one with the potential to rip apart a spacecraft or satellite.
A concept, known as the Kessler Syndrome, describes the nightmare scenario that would develop if a cascading series of such collisions in the near-Earth orbit destroyed every satellite above Earth, causing havoc to global communications and travel.
Mr Wayman said the growing number of satellites being launched up into space everyday was a big issue.
“The problem is that as they stop working, … they become a risk of colliding into each other,” he said.
“And when they do that they create huge amounts of space debris that then collide into more space debris, and it’s a big snowballing problem.
“And one of the main ways of solving this is to capture some of those large pieces of space debris and bring them back out of orbit, so that they can’t collide with anything.”
Mr Wayman said if the problem of space debris was not solved, then the amount would only continue to grow, until it was impossible to launch future satellites.
“That would be a real problem because we wouldn’t be able to use any of the weather forecasting satellites that we rely on, any telecommunications satellites, any of those kind of things,” he said.
First whales, now space junk
While the harpoon has been used throughout history, the new space version has undergone a few upgrades
Airbus engineer Pete Steele said though it was unlikely a whaler would recognise their harpoon, there were some similarities between the two.
“I mean, the point of a harpoon is that it has barbs,” he said.
“The old whalers’ harpoons, they didn’t have the technology to deploy them after impact, but we’ve managed to develop that.
“We then pierce the target panel of a satellite, we get to this point and the barbs deploy, we then have a locked satellite.
“We now can pull on it, it’s not going anywhere.”
Testing in the laboratory has shown the space harpoon would easily penetrate the shell of the satellite, before deploying spring-loaded barbs to prevent the target from escaping.
Next month, scientists will launch a small, test-version of the space harpoon, along with a piece of mock “space junk” for testing in the real-world conditions of space.
Meanwhile other methods for removing space junk are also being developed in other laboratories.
The European Space Agency has been working on garbage-collecting robotic arms for spacecraft and even big nets for scooping up other more elusive objects.