Space may not actually be as big as we imagine, at least not the space that directly surrounds our planet. When we gaze up into the night sky, romantically spotting stars we may have more of a chance of browsing items in the cosmic junk yard.
With more than 5,000 launches of various shuttles, satellites and other equipment in the last 60 years, space is becoming congested. Space trash is becoming a real problem …space rage may be the next thing to hit the headlines.
You may have seen the impact that space trash had on Sandra Bullock in the blockbuster movie Gravity, but surely that isn’t something that could affect us right? Well it could be more of a problem to our daily lives than we realise.
There are non-lethal ways that space junk could interfere with our daily lives. GPS signals, international phone call connections, TV signals and weather forecasts could be disrupted. But it could also have more serious implications.
It is debris, mostly man-made, consisting of a variety of non-functional left overs of space missions. Out-Of-Commission space vehicles, broken satellites, spent rocket launch stages, objects that have been ‘dropped’ by astronauts, including a glove, a tool box, nuts and bolts – and then fragments which result from collisions between these.
There are millions of fragments of debris, some as tiny as grains of salt rushing around the globe at speeds of around 17,500 miles per hours.
500,000 pieces of space debris between 1 and 10cm
More than 21,000 pieces larger than 10cm
More than 100 million pieces below 1cm
Most orbital debris is within 2,000km of the Earth’s surface
The greatest concentrations of debris are found at 750-800km
Travel up to speeds of 28,163 km/h (17,500 mph)
Only 7% of space junk is functional
The amount of debris varies at different orbit levels around the Earth.
Low Earth-orbit (LEO), is between the distances of 125-1,250 miles from the surface. At this level, space junk is directly affected impacted by the atmosphere, which degrades their orbit – dragging the pieces back to Earth.
Semi-synchronous orbit is between the distances of 6,000 to 12,000 miles above the Earth. This is mostly used for navigation and communication satellites.
Geo-synchronous orbit is that above 22,000 miles from Earth. This is the best for satellite telecommunication and weather satellites. Items here can remain in orbit for millions of years.
Much of the trash flying around the Earth is a result of normal space missions. Simply satellites that have ceased to be useful, or launch stages of rockets that are shed intentionally. Rubbish has been jettisoned from Space Stations over the years, as astronauts spend extended periods of time in a confined space.
There have also been mistakes and human error which have caused additional pieces of debris, as mentioned, dropping items such as gloves. Over time, collisions between the junk in space has exacerbated the problem, created thousands of smaller individual pieces of debris over time.
Inconceivably, in 2007 China intentionally destroyed a Chinese weather satellite in a test to measure the ability of an anti-satellite missile, creating a considerable amount of junk in it’s wake.
“The greatest risk to space missions comes from non-trackable debris,” said Nicholas Johnson, NASA chief scientist for orbital debris.
Space junk can be deadly in space, even debris as small as a flake of paint can cause enormous damage. This is due to the mind blowing speeds that the particles are travelling at, and also because of the unique design of life-supporting vehicles. To sustain human life it is necessary that individual modules are pressurised to a vacuum. These are particularly vulnerable to damage by piercing.
Despite the huge number of defunct objects in space, the number of collisions is relatively low. This could be due to the physics: all objects in orbit move at the same speed, so any gap between them would remain the same. They wouldn’t get closer together at any point, if they just continued along their path. And that is exactly what they do….most of the time. As soon as an orbiting object fractionally increases its speed, it will climb to a slightly higher orbit. It is at these shifting points that collisions can occur. There is another chance for collision in situations where two satellites orbiting at the same altitude but at different inclinations, cross paths.
Debris avoidance maneuvers are planned when the probability of collision from a conjunction reaches limits set in the space shuttle and space station flight rules. If the probability of collision is greater than 1 in 100,000, a maneuver will be conducted if it will not result in significant impact to mission objectives. If it is greater than 1 in 10,000, a maneuver will be conducted unless it will result in additional risk to the crew. Debris avoidance maneuvers are usually small and occur from one to several hours before the time of the conjunction. Debris avoidance maneuvers with the shuttle can be planned and executed in a matter of hours. Such maneuvers with the space station require about 30 hours to plan and execute mainly due to the need to use the station’s Russian thrusters, or the propulsion systems on one of the docked Russian or European spacecraft. ~ Nasa
There have been other notable collisions:
Space trash is constantly falling out of orbit. In fact, at least one piece has crashed towards Earth every single day in the last 50 years. We don’t tend to hear about this in the news, as the vast majority is burned up on re-entry into the Earth’s atmosphere and never makes it to the surface. Much of what does remain intact lands in the sea, which covers around 70% of the surface. To date there has been no serious injury or significant damage to property, according to NASA’s Orbital Debris Program Office. There have of course been a small number of newsworthy space trash crashes on earth. In 1979 the US space station, Skylab fell out of orbit and crashed down to Earth, scattering debris across the Indian Ocean and a (fortunately) low-populated part of Western Australia. In 2001 a huge, 15 year old Russian space station Mir also fell out of the sky. The majority of it’s mass was burned up on re-entry but over a thousand fragments reached Earth, and many were filmed by holiday-makers in Fiji at the time. In 1997, Lottie Williams was hit by a piece of Space Junk and was completely unharmed! “The weight was comparable to an empty soda can,” Williams told FoxNews.com. “It looked like a piece of fabric except when you tap it, it sounded metallic.” There is a large piece expected to impact in November 2015:
Scientists have predicted that a rogue piece of space junk will impact Earth at 6:20 UTC on 13 November, falling into the Indian Ocean about 65 kilometres off the southern tip of Sri Lanka. Dubbed WT1190F, the curious object was rediscovered just this month after scientists lost track of its orbit far beyond the Moon and all but forgot about it. Now the space debris, which is thought to measure between 1 and 2 metres long, is on a collision course with Earth, and presents a rare opportunity for scientists to watch the entire impact event from beginning to end. ~ Space
Brian Weeden, a technical adviser for the Secure World Foundation describes space junk as a ‘super wicked problem‘. As well as the huge amount of debris already in orbit, there are a number of small,cheap satellites being sent to space by private companies. This could further exacerbate the problem. In addition to this there is a potential scenario, known at the Kessler Syndrome which should be taken into account. The Kessler syndrome would occur if the amount of space trash in Low Earth Orbit reaches a critical level. The amount of debris would see a constant stream of collisions, meaning a steady rise in debris greater than the speed of degradation due to atmospheric pull (described above). This would make the low Earth orbit virtually impenetrable.
As an individual, you can track the space debris yourself using one of the dedicated websites that are popping up. Stuff In Space, designed by James Yoder, tracks thousands of objects in realtime. “The website displays anything currently trackable — low-earth orbit, geosynchronous, and anything else there is” ~ Yoder
Scientists have begun to suggest a number of innovative, highly creative solutions to the space trash problem. The issue is more than technical though, with enormous political and even bigger financial problems to overcome. Some think it is a case of reduce, reuse, recycle on a grand scale.
There have even been suggestions of something like a giant pac-man munching the debris!
We have already suggested that space junk could cause problems with the technology that we have come to rely on – GPS and weather forecasts for example.
But on a bigger scale, it is quite shocking to realise that we are impacting not only our planet with our junk, but also the space that surrounds us.
The more that is out there will surely only mean that more will fall to Earth. And what if the low robing trash eventually cuts us off from space, preventing future space travel due to the danger to launch?
Certainly something to think about. What are your thoughts?
We would love to hear from you.
Copyright © 2002-2013. All rights reserved