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Space Debris Illustrated: The Problem in Pictures

Trackable objects in Earth ORbit.  Image Credit:  ESA
Space junk, space debris, space waste — call it what you want, but just as junk and waste cause problems here on Earth, in space spent booster stages, nuts and bolts from ISS construction, various accidental discards such as spacesuit gloves and cameras, and fragments from exploded spacecraft could turn into a serious problem for the future of spaceflight if actions to mitigate the threat are not taken now. The European Space Operations Centre has put together some startling images highlighting this issue. Above is a depiction of the trackable objects in orbit around Earth in low Earth orbit (LEO–the fuzzy cloud around Earth), geostationary Earth orbit (GEO — farther out, approximately 35,786 km (22,240 miles) above Earth) and all points in between.

Trackable objects in Low Earth Orbit.  Image Credit:  ESA
Between the launch of Sputnik on 4 October 1957 and 1 January 2008, approximately 4600 launches have placed some 6000 satellites into orbit; about 400 are now travelling beyond Earth on interplanetary trajectories, but of the remaining 5600 only about 800 satellites are operational – roughly 45 percent of these are both in LEO and GEO. Space debris comprise the ever-increasing amount of inactive space hardware in orbit around the Earth as well as fragments of spacecraft that have broken up, exploded or otherwise become abandoned. About 50 percent of all trackable objects are due to in-orbit explosion events (about 200) or collision events (less than 10).
Impact from space debris on shuttle window
Officials from the space shuttle program have said the shuttle regularly takes hits from space debris, and over 80 windows had to be replaced over the years. The ISS occasionally has to take evasive maneuvers to avoid collisions with space junk. And of course, this debris is not just sitting stationary: in orbit, relative velocities can be quite large, ranging in the tens of thousands of kilometers per hour.

For the Envisat satellite, for example, the ESA says the most probable relative velocity between the satellite and a debris object is 52,000 kilometers per hour. If a debris objects hits a satellite, the ISS or the Shuttle, at those speeds it could cause severe damage or catastrophe.

Space Debris in polar orbit.  Image Credit:  ESA

Above is a depiction of debris in polar orbit around Earth. From the image below, it’s evident how explosions of spacecraft causes even more scattered debris. Even after the end of the mission, batteries and pressurised systems as well as fuel tanks explode. This generates debris objects, which contribute to the growing population of materials in orbit, ranging from less than a micrometer to 10 centimeters or more in size.
An upper stage of a spacecraft exploding.  Image Credit:  ESA

About 40% of ground-trackable space debris come from explosions, now running at four to five per year. In 1961, the first explosion tripled the amount of trackable space debris. In the past decade, most operators have started employing on-board passive measures to eliminate latent sources of energy related to batteries, fuel tanks, propulsion systems and pyrotechnics. But this alone is insufficient. At present rates, in 20 or 30 years, collisions would exceed explosions as a source of new debris.

2112 future simulation.  Image credit: ESA
The ESA says it is crucial to start immediately to implement mitigation measures. This image shows a simulation of the the 2112 GEO environment in the case when no measures are taken. In the top panel, with mitigation measures, a much cleaner space environment can be observed if the number of explosions is reduced drastically and if no mission-related objects are ejected. The bottom panel shows the “business-as-usual” scenario, without any mitigation measures taken. However, to stop the ever-increasing amount of debris, more ambitious mitigation measures must be taken. Most importantly, spacecraft and rocket stages have to de-orbited and returned to Earth after the completion of their mission.

They’ll burn up in the atmosphere, or splash down in uninhabited ocean areas. In the case of telecommunication and other satellites operating in the commercially valuable geostationary zone, they should boost their satellites to a safe disposal orbit, as shown below.
Graveyard orbit.  Image credit:  ESA

There are other measures, like reducing the number of mission-related objects and controlling the risk for reentry, but these are the basics. The issue is that such mitigation measures cost fuel and operational time, and therefore they increase cost. In the commercial world, this may competitiveness, unless there is an international consensus to accept such costs.

Original News Source: ESA


Nancy Atkinson is currently Universe Today's Contributing Editor. Previously she served as UT's Senior Editor and lead writer, and has worked with Astronomy Cast and 365 Days of Astronomy. Nancy is also a NASA/JPL Solar System Ambassador.

Comments on this entry are closed.

  • Mikey May 19, 2008, 6:13 AM

    thanks for the news

  • Sherri July 5, 2008, 9:57 AM

    We may as well put a “No Vacancy” sign up on Earth. That’s where we are headed.

  • Sherri July 5, 2008, 10:00 AM

    Ant: I’d love to know where you get your information about “Fifth dimentional energy”

    Global warming isn’t real to you? Greenhouse gases is made up and ‘crap”

    Just how long do you think we can do what we do to the planet and NOT pay a price?

    I’m not religous either. But I am educated.

  • Philip August 29, 2008, 7:08 AM

    If we can get all this space debris back to earth, or the moon, or to a space station, can it be recycled so we don’t have to fight the gravity well to send precious metal into orbit? I know it will be years and years in the future, but what else will we do withall this space debris? Toss it? Isn’t that how we got into this mess in the first place? I am not a tree hugger, just a pragmatist, I think :)

  • Toby1 September 28, 2008, 9:48 AM

    I would put a big parabolic mirror up there and focus the suns radiation into a beamm and vaporise them. They would be harmless if turned into gas.

  • Kelli September 29, 2008, 12:35 PM

    All I can say is NOT-SO-MUCH!!!!LOL!!!!

  • NAL October 5, 2008, 8:45 PM

    Here is a tv-show based on this subject.

    broadcaster (dot) com/clip/24640

  • Willy dilly. October 5, 2008, 8:47 PM
  • mystery fish January 16, 2009, 11:33 AM

    i ? this website

  • mystery fish January 16, 2009, 11:34 AM

    i ? this website

  • mystery fish January 16, 2009, 11:35 AM

    (the ? is supposed to be a heart (alt+3))

  • john black January 17, 2009, 1:08 AM

    Generally I do not post on blogs, but I would like to say that this post really forced me to do so, really useful information.

  • Satweavers January 21, 2009, 11:55 AM

    There was a shortlived TV comedy in the late ’70s about Space Garbage Men called “Quark” . I never watched it, but might have if I’d known how visionary it was. It’s hard to imagine a solution to this problem. Retrieving the stuff, chasing it around, matching velocities, even with an autonomous vehicle would require too much fuel. If the satellite killing inertial impact vehicles proposed for security and anti satellite are ever used, we can say goodbye to GPS, weather forcasting, media broadcast, and all critical telecommunications and data transfer. We would be doomed!

  • nick January 28, 2009, 8:20 AM

    Ant: i dont know much but i do believe in space junk or ‘crap’ as you put it. I dont know why you think that global warming isnt real? Yes i am religious and i believe in one Plan that i can do anything about but i do believe in what ive seen and not “Fifth dimentional energy”. thanks with love,


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  • Shaula Brant February 14, 2009, 1:37 PM

    We definitely need to get the junk and defunct satellites out of orbit, at least where they pose the most dangers, but having every piece of junk deorbitted is not a real solution either. It would be nice if these items could be placed in a storage orbit, or placed at one of the Earth – Moon Lagrange points (L4 or L5). Use something along the lines of a solar sail to move the stuff; it would take some time to move items, but every little bit will help. They would be out of the way and could be used again as raw materials once we have a more permanent presence in space. Place a solar concentrator out there and melt it down for salvage…along with materials from the moon, to aid in our effort to continually humanize space.

    Same thing could even be done for the Hubble telescope, but with that one, maybe it could end up as a part of an on-orbit museum piece at L5.

    Idealistic…perhaps…but that and other ideas are out there.

  • jeff March 31, 2009, 9:08 PM

    hey baby

  • joe March 31, 2009, 9:10 PM

    you guys suck balls

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