This is the third and final part in a short series that explores the issue of space debris surrounding our planet. For part 1 click here and for part 2 click here
Don't Blow Up A Satellite - Even If It Is Yours.
9 years ago on the 11th January 2007, the Peoples Republic of China launched a missile carrying a kinetic weapon into space and destroyed one of its own old weather satellites. The satellite's name was Fengyun-1C (Fengyun stands for Wind Cloud I believe). Although the weapon was kinetic and relied solely on impact to destroy its target, the resulting destruction caused 3,037 pieces of debris greater than 5cm which accounts for 22 percent of all objects in low earth orbit (below 2000km). Source. There were also an estimated 35,000 objects between 1 to 5cm created. Source
The debris cloud from this incident has now spread like a blanket over the earth. The picture below shows: - on the left - The orbital planes of the debris after one month. Centre - the orbital planes after 6 months - notice how they start to spread apart - and on the right - the orbital planes after 2 years. The debris pieces now blanket the globe during their orbits.
The majority of this debris will pose a distinct threat to other orbiting satellites for many years to come
What Can Be Done To Mitigate The Amount Of Debris?
Well, the most obvious thing is to not blow up a satellite! Other than that there are some new technologies being developed to accelerate the decay of objects into the earth's atmosphere once they have reached the end of their useful life. One of the most interesting is the use of 'space sails' that increase the surface area of a satellite and hence the drag effect. This causes the satellite to fall to earth faster.
One of these sails is currently being tested in orbit as I write. A satellite that regales in the name of EGG (re-Entry satellite with Gossamer aeroshell and Gps/Iridium) which has been developed at the University of Tokyo, has deployed an aeroshell and should re-enter the earth's atmosphere before too long.
A picture of the EGG Satellite with the aeroshell (the yellow hexagon structure) deployed. Source
After the Iridium 33 / Cosmos 2251 collision in February 2009 (Details in part 2 of this series - here) government agencies and private industries involved in space are now coming together to plan for the future reduction of space debris. These measures will take many forms and include legislation to minimise the orbit lifetime after a satellite is decommissioned, the forceable reentry of rocket bodies after a launch and the ongoing development of new technology such as the space sail discribed above.
Does It Matter?
I hope that through this series of posts I have highlighted the dangers of space debris and its possible impact for everyone here on Earth. Think about how modern life would be affected if we suddenly lost our communication, navigation and weather satellites? Not only would it be very costly and a huge inconvenience but also potentially life-threatening.
I hope you have enjoyed this post and would consider following me (I will reciprocate). Some of my posts are about mental health issues while others cover a wide range of subjects. For a taster of my musings please follow these links:-
A local landmark created by a giant....well maybe.
Space Debris - Part 1 - The Problem
More about Space Debris - Part 2 - The Effects
A Dome For All Seasons - Part 1
A Dome For All Seasons - Part 2 - The saga continues.....
Is social media a force for good?
Sunset over the North Yorkshire Moors
My first attempt at digital art
How too much news may not be good for us
Another one on how dogs can help us
Until next time - take care of yourselves....