By the time we’ll be seriously considering the selective recycling of the intergalactic trash we generate, many a dead satellite or lost toolbox will pass overhead, where no-one can hear you scream. But we have plenty of time to get used to solutions that go beyond the sci-fi domain and become the reality of our daily news.
As the exploration of extraterrestrial space became part of our daily lives – from the discovery of cosmic rays, using a balloon, in 1912; to space tourism, started in 2001; to the launch of the first Romanian nano-satellite – inter-galactic ecology was and remains a hot and controversial topic. First estimated at 14,300,000 tons per year in 1957 by Hans Pettersson, through optical measurements, the amount of trash we produce has evolved alarmingly, according to a NASA-coordinated study last year. Compared to 2006, the number of space objects larger than 10 cm grew from 9,949 to 16,094. 20% of these were generated by a test of anti-satellite technology done by China in 2007, which resulted in the ground-controlled destruction of Feng Yun (FY-1C), the Chinese weather satellite.
There are solutions for ecologizing outer space – already being polluted for decades – but none are cheap or easy to apply
Since the beginning of the Space Age there have been over 5,000 missions, all generating various debris – from tools used to repair the International Space Station, to satellites like Envisat, with 8 tons of hardware, worth 2,9 billion dollars, becoming useless in 2013 and endangering Earth’s atmosphere for the next 150 years. Not to mention lost Russian watches; Laika, the first dog in space, still circling the Earth; or ghost cosmonauts lost among the stars.
Specialists define two types of trash, which either threaten orbiting satellites, or could at any time enter a collision course with our planet. This can either be naturally-occurring debris, produced by comets and asteroids; or man-made debris – including satellites, garbage, tools left in outer space and various other objects launched into orbit. The history of intergalactic junk starts with a piece of the rocket that placed Sputnik-1 into orbit, the first artificial satellite, successfully launched by the Russians in 1957. Over time, space debris evolves in accordance with the Kessler syndrome – every collision, no matter how small, generates a chain effect that will, in the long run, stop space exploration and the launch of new satellites.
The first major accident to give scientists serious food for thought occurred on February 10th, 2009, when satellites Kosmos 2251 and Iridium 33 clashed at 42,000 km/h and were both destroyed on impact. The presence of space trash affects astronomical study, by adding artifacts to images, or by obstructing telescopes on Earth, or on satellites specialized in continuous space scanning, such as Hubble, or the recently-launched Stereo telescope, which takes 3D images.
There have been mentions of solutions to avoid the layer of cosmic debris, orbiting our planet at approximately 30,000 km/h, even as far back as 1946, when the first composite material was designed to protect space modules from micro-meteorite impact. Today, the latest materials engineered by 3M are based on an alloy of Kevlar and Nextel, resulting in a material 2.5 times lighter than the aluminum foil used until now, and efficient when faced with particles smaller than 1 cm. These particles make up the most part of the 30,000 fragments identified and monitored by NASA, with at least one of them falling out of orbit every day.
The most pessimistic scenario has space junk blocking the sunlight, and generating global climate change. Though there is no international treaty to minimize the production of space debris, there are a few methods, mostly experimental, of ecologizing the space we pollute – other than protecting equipment against the constant exposure to interstellar trash.
One such method, already tested on the French satellite Spot-1, is to remove unused equipment from orbit, thus reducing its lifespan in space from 200 years to 15. The operation would theoretically be run by using a giant laser sweeper – it was studied during the Orion project, but never used as anything other than a measuring tool, since international law prohibits placing such powerful lasers within range of cosmic flights. According to a NASA study published last year, a 5 KW laser can push debris through space at speeds of 200 m/day – quite inefficient for an expensive intergalactic broom (500 million dollars’ worth) than could cause collateral damage at any time.
Another method, proposed by the German Space Agency, is to build a shield, also known as NEOShield, which could modify the orbit of space debris using nuclear explosions or an electromagnetic noose. Not exactly a practical solution, considering that the explosions could influence measuring instruments already in space, and make an ever bigger mess judging by the Kessler effect. The research project would take three years, and be financed by the European Community, with 4 million euro, and international partners, with 1.8 million euro.
The Swiss Space Center recently proposed another method for cleaning outer space, using machinery specialized in recovering out-of-control equipment bigger than 10 cm. With the CleanSpaceOne project, completely robotized intergalactic garbage cleaners would hunt for debris, at 28,000 km/h, at an altitude of up to 800 km; they would send junk off-orbit and to various locations where it could be safely destroyed. The first symbolic targets chosen are the pico-satellite Swisscube, and Tisat-1, launched a few years ago. The project will become operational within a few years, thanks to strategic partnerships with NASA and a budget of 10 million Swiss francs.
It seems we’ll be witnessing an increase in sci-fi action, with robots and a lot of space junk in the night sky, as in 2015 the Canadians also plan to launch a space shuttle – this one specializing in recharging the batteries of functioning satellites and recovering the ones that are out of use and polluting our atmosphere. With a 300 million dollar budget, the project was initiated by the MDA Corporation and Intelsat – a company that started up in 1964, and currently controls a fleet of 52 communication satellites.
The ElectroDynamic Debris Eliminator is another solution suggested by a private company in South Carolina, and seconded by DARPA. According to estimates, by 2030 space-cleaning ships could be getting rid of as many as 50 objects a year, from rocket debris to smaller particles that it could pulverize with lasers. The first test flights are programmed for 2013, when electro-dynamic fishing nets may start dragging useless equipment into the Pacific Ocean, or even recycling it on location, in outer space.
Editor’s note: a big thank you goes to Crina Căliman who managed to translate our not quite easy to translate romanian article.