We are endlessly encouraged by environmental savvy authorities and agencies to "reduce, reuse and recycle". In our backyard [garden] we have a blue wheelie bin for all our plastics, metals, glass and cardboard, a caddy for junk mail and other paper waste, a green bin for all compostable kitchen and garden waste and even in the black bin, the contents of which are perhaps ultimately destined for landfill, are the dregs of daily life that will be digestively heat treated by our local refuse center to extract an organic slurry that can be further processed for safe fertilizer. Any broken electrical goods that simply cannot be fixed must be taken to another recycling center from whence they are processed under various regulations to extract useful metals and plastics and render any remnants safe to landfill.
On that question of landfill, it occurred to me as a school kid first learning about science that landfills might become the opencast mines of the future, there must be huge tonnages of metals, plastics, and glass locked underground in these sites just waiting to be tapped. They could become particularly important for our children's' children who may well face much-dwindled supplies of rare and irreplaceable metals that we have squandered in our electronics since the 1960s.
Then, arrived a press release from the RIKEN's Computational Astrophysics Laboratory, in Japan about space junk. RIKEN, Rikagaku Kenkyusho. In case you don't know is a research institute founded in 1917 that now hosts about 3000 scientists over seven campuses with its main site in Wako just outside Tokyo. With an annual budget of 88 billion Yen (about US $760 million), one would imagine that a lot of interesting science is being done by those 3000. And, their latest press release is testament to that: "A blueprint for clearing the skies of space debris". What a title! What potential!
My immediate thoughts were of a giant version of the Intruder spaceship from the James Bond 007 movie, You Only Live Twice. The Intruder would open its enormous, flower-like cargo doors and ingest all the broken satellites and other space debris. It could then return to Earth, shuttle-like, and deposit its payload at a space junk recycling center. This would be a cosmic task with the RIKEN release alluding to the 3000 tonnes of derelict satellites, rocket components, and fragments produced by collisions between debris orbiting the Earth right now with the number of pieces of debris having doubled approximately during the last decade.
Unfortunately, for my space age, school-kid's brain, the RIKEN release describes a slightly less recyclable rather than a down to Earth solution. The team, which includes international colleagues, has proposed in the journal Acta Astronautica a detection system that uses a super-wide field-of-view telescope developed by RIKEN’s EUSO team to find the space debris. It also repurposes a recently developed high-efficiency laser system, the CAN laser reported in Nature Photonics in 2013, to track the detected fragments and remove them from orbit. The blast of laser light hitting a piece of space debris causing high-velocity plasma ablation. The Newtonian reaction force to this lowers the orbital velocity of the fragment nudging it into a re-entry trajectory, which will lead to it burning up in the earth's atmosphere. The team's specific first application for the system would be to use it to remove space debris from close to the orbit of the International Space Station (ISS) and so make life safer for the astronauts and cosmonauts aboard that craft.
Team leader Toshikazu Ebisuzaki of EUSO explains that, "We believe it is a more manageable approach that will be accurate, fast, and cheap. We may finally have a way to stop the headache of rapidly growing space debris that endangers space activities. This dedicated system could remove most of the centimeter-sized debris within five years of operation."
Well, that's a grand plan for those tiny fragments, but I'm still keen to see the launch of an Intruder type spacecraft that could suck up all the bigger chunks of equipment up there and bring them back to Earth for recycling. Of course, the Intruder would have to be launched from a base deep within an extinct volcano, and my school-kid brain would have me sit with the fluffy white cat on my lap as I press the big red button to start the countdown. Now, 007, what do you think of that dastardly plan, mwahahahahaaaaghhh?
David Bradley blogs at Sciencebase Science Blog and tweets @sciencebase, he is author of the popular science book "Deceived Wisdom".