Space junk at 'tipping point', now getting worse on its own

Satellites and spacecraft face the growing risk of damage and failure thanks to the expanding volume of small pieces of junk hurtling around the Earth's orbit. Scientists have warned the amount of orbital junk has reached a tipping point in volume and size. The National Research Council has said in a report (here) that …

[John Arthur]

Really?

"So far the problem has been largely restricted to low Earth orbit (LEO), but geosynchronous Earth orbit (GEO) could suffer the same fate over a longer period of time."

Shurely a piece of junk in geosynchronous orbit is not moving relative to the other pieces of junk there so will not collide with it. Anyway it is all over the Equator so who cares?

[Sir Runcible Spoon]

Sir

"Shurely a piece of junk in geosynchronous orbit is not moving relative to the other pieces of junk"

Methinks you need to revisit Newtons laws of motion.

Just because there is a position in the orbit of a planet whereby zero energy input is required to maintain a static overhead position of somewhere on the surface, does not mean that nothing moves in this band.

How do you think the satellites got there in the first place??

[Steve Davies 3]

Doh!

Yes the junk might not be moving relating to other bits in geosync orbit BUT what happens when you want to put a $500M Satellite right where said junk is? Boom? then you have thousands if not millions more bits of junk right where you don't want it.

time to send those bin men with the iPads up there to sweep things up....

[Bob H]

To GEO or not to GEO

Ah, what you need to remember is that when they talk about GEO they are talking about satellites which are just the right distance from the earth to orbit at (relatively) the same rate as the surface of the earth. That doesn't mean that a piece of junk couldn't be flung out there, or that a damaged satellite in GEO couldn't send off debris which might cause damage. Being in the GEO orbit doesn't mean that material isn't moving, merely that objects which stop there are more inclined to stay there (relative to the surface).

The moon, varying density of the Earth and other celestial bodies all exert forces on space objects, so as much as satellites need small adjustments to stay in position, objects which don't have station keeping systems can be pulled into inconvenient locations.

Regards, Bob (for whom 5 years of dealing with the foibles of space was a living)

[It wasnt me]

No so, Im afraid.

Just last week the AM4 satellite failed to enter GEO. The craft is now completely lost in a highly inclined geosynchronous transfer orbit.

In plain english, its now out of control, in an orbit varying in height between 1000 and 21000 km, inclined at 51 degrees.

In plainer english between now and the end of time it will cover the entire volume of space between those two heights, approximately between the latitudes of london and Buenos Aires.

It's not the only uncontrolled piece of junk in a similar orbit.

Don't you think it will be more impressive if it _doesn't_ hit anything?

The chinese were infinitely irresponsible with their satellite desctruction test and proved themselves to be an unworthy and immature space nation. If they really wanted to prove the technology they could have shot down a much lower satellite that would have re-entered earths atmosphere, as the Americans did.

Instead they took the first step towards shutting the gates completely on any desires to leave earths atmosphere. Not just for themselves but for all mankind, for a duration that is measured on the geological timescale.

Unless someone starts taking the problem seriously we will see that the Kessler Syndrome is real, and the Chinese have wilfully brought it on.

Disclaimer: my job is at stake if satellites become no longer commercially viable. A surprising amount of the UK GDP is also. In fact, with the support industries, your job is probably at stake.

[Ken Hagan]

Re: Really

I agree. The GEO problem sounds like FUD.

GEO satellites are only useful to the extent that they sit in equatorial orbits, so they presumably do form an orderly queue around the Earth with small relative velocities. Also, with fewer spacemen dropping hammers and fewer chinese missiles there is a lot less junk being produced to fill that space. Lastly, at a radius of 23500 miles, there's several orders of magnitude more room to play with than in NEO.

NEO satellites move within a smaller volume and generally don't sit in equatorial orbits so they may have relative /transverse/ velocities of many thousands of miles per hour. That will make a real mess of anything (or anyone) it hits. This isn't FUD. This is "just a matter of time".

Probably another reason to "go slow" on that manned space program. Robots don't have wives and children watching on TV back home.

[Anonymous Coward]

FUD?? actually it's know as FOD

Foreign Object Damage.

[Jared Hunt]

I'm sticking up for John Arthur on this one

The relative velocities in different bits of junk in LEO are vastly different to GEO. Objects in GEO all have to be in an equatorial orbit, in the same direction as the rotation of the earth and at the same velocity in order to maintain their relative position above the ground.

Objects in LEO are under no such constraint, the can be in polar orbits, equatorial orbits and every inclination between.

I'd say there is a lot more danger of objects colliding destructively when they're flying perpendicular to each other than from objects that are all moving in the same direction at the same speed. Even when launcing new GEO satellites the rocket has to match speed and direction for the same reasons so there's still very little chance of a collsion.

[Vulch]

GEO isn't stable

Due to the Earth not being a sphere and having the moon going round it and both going round the sun geostationary orbits aren't stable. The lifetime of a satellite up there is largely determined by the amount of station keeping fuel it can carry.

Left to their own devices the satellites start drifting up and down so that from the ground they don't stay in one place but appear to loop round a figure of eight over the course of the day. Over time the inclination of the orbit gets higher and higher, so the figure of eight looks larger and larger. From the point of view of another satellite in GEO the drifting satellite is moving in a circle, crossing GEO twice a day at right angles, the bigger the circle, the faster it's moving relative to GEO so the worse any collision will be. Debris from a collision at any altitude spreads into different orbits very quickly so eventually you have bits coming at you from all directions.

[John70]

Scrap metal

Just send metal theives into orbit, they can scrounge for the scrap metals.

[fridaynightsmoke]

Space tatters

... all we need to do is develop a spacefaring Transit dropside van...

[TeeCee]

Re: Space tatters

There's one for sale down the road.

Well, it's got spaceship milage on it.........

[John Dougald McCallum]

Space Pickup

Sorry the yanks have just scraped it.

[Anonymous Coward]

Scraped it you say?

Don't worry that'll polish out.

[BristolBachelor]

Rockets for scrap metal thieves?

I'm not sure what type of rocket would be best. Strap the thief to a chair with a pile of gun-powder underneath and douse in petrol, stand well back and throw a match?

[amanfromearth]

Yeah

SpacePikeys !

[Marvin the Martian]

Tipping point?

Given what they're doing up there, that should obviously read "fly tipping point".

[Anonymous Coward]

@John70

Genius! I think you've just solved the Dale Farm problem!

[Anonymous Coward]

Let's build a rocket

I say let's build a rocket! Let's see, we can make the capsule of of that cement mixer, use those old tanker trailers as the fuselage. I have some old explosives as fuel. We need a name...

How about "The Vulture"? That would be apropos.

Mine's the "Broderick Salvage" one...

[Winkypop]

I wonder how long

...it would take for all the crap to become captured by Earths gravity and burn up in the atmosphere.

Assuming nothing new was launched of course. 100 years, 1000 years???

I see NASA are helping to keep space clear.

[Chris 244]

Captured by Earth's gravity?

An orbit is a gravitationally curved path of an object (e.g. "crap") around a point in space (e.g. Earth). Ergo all of the "crap" is already "captured". In fact it never really escaped.

I think you mean slowed sufficiently through atmospheric drag to cause re-entry.

[Anonymous Coward]

Fylingdales

That's one of the jobs that RAF Fylingdales does, keep an eye on whats going on up there. Even when the space shuttle was launvhed it became an entry in the database for tracking.

[Naughtyhorse]

looks like we can now say...

mankind has truly arrived in space, and true to form is filling the place up with his shit.

well done us!

[BristolBachelor]

LEO yes, GEO, don't think so

I can understand the problem in LEO; there are lots of different orbits in different planes, different altitudes, different amounts of circularisation, different inclinations, etc. This all means that things that com into contact can be travelling at very different velocities (leading to spectacular events).

However in GEO, everything runs in a flat plane level with the equator, and at a fixed altitude, so they all go around together. Old things get pushed out to a higher altitude. Anything left un-powered at the normal GEO altitude will gently drift to one of a few dead-spots. I don't think that there is much chance of things coming together up there.

[Rob Carriere]

GEO usually isn't

If all the satellites in "GEO" actually were in GEO, there wouldn't be much opportunity for high-speed collisions. Many of them orbit at a slight angle to the equator, however, and that gives you the opportunity for collision at several kilometers per second.

The slight angle is the reason you see figure-8 curves when the position of the satellite is plotted on a map of the Earth. If the orbit was truly equatorial, the position would be a single point.

[It wasnt me]

No so.

See my earlier post. If everything works well then its all on the same plane (nominally, but in reality +/- 3 ish degrees). However it doesn't all work well. See AM4 reports for that.

The old things getting pushed to a higher altitude is a convention that has been brought in amongst satellite operators for exactly this reason. It doesnt apply to old satellites and ones over which you have no control.

Finally the unpowered ones will as you say slowly drift to a stable orbit. Those stable points are approximately 75deg east and 105deg west. Over the indian ocean and in prime position to broadcast to the whole of the americas. To call them 'dead spots' is complete nonesense. The unpowered satellites don't just drift there either. Their orbital position slowly oscillates around the dead spot whilst decaying. As it does so the eccentricity of their orbit increases.

Commercial satellite operators routinely move their satellites out of the way of these rogue wondering junk satellites. Eventually 2 will collide, not at LEO velocities but still enough to make a mess up there.

Really, the notion that GEO satellites just stay put and don't move realtive to each other is just not true.

[Ian Stephenson]

Salvage 1

Anyone remember that (short lived) series?

Venture Capital opportunity me thinks.

[Bill Cumming]

@ John Arthur

GSO does not mean "not moving" it means moving forward at the same rate as falling towards the ground. (Remember Douglas Adams explanation of flying " falling towards the ground and missing")

Things are still whizing about at a few hundred meters per second.

Also it's not all in a nice circle around the equator, they tend to pass overhead as well...

[Anonymous Coward]

Surely ..

it (geostationary) means just that - the satellites are not moving relative to the ground and therefore each other.

From Wikipedia :

"Satellites in geostationary orbit must all occupy a single ring above the equator."

[David Taylor 1]

@Bill Cumming

No, you've just defined "orbit" not "geosynchronous orbit". ALL orbits are "falling towards the ground and missing".

There are two special features of a GSO:

1. The period of the orbit is the same as the rotational period of the Earth (~24 hours).

2. The orbit is aligned with the Earth's equatorial plane.

As a result, from the point of view of an observer on earth, the satellite does not move.

From the point of view of a bit of space junk ejected from an exploding satellite, it's no different to any other orbit. But luckily, everything we try to put into the GSO belt tends to go in the same direction, which should help.

[ratfox]

Call Disney

I remember an old Scrooge McDuck story where he went up in space to collect all that junk... And sell it to collectors back on earth.

[Kevin Johnston]

I wonder

how much it would cost to put together an LEO dustpan and brush with re-entry capability. Could you get enough back on the scrap to self-finance?

[Remy Redert]

@Bill Cumming

Just to correct you. Relative speeds of up to 7km/s are possible in GEO. At those speeds, objects impacting eachother pack several times more kinetic energy than exploding TNT.

Also, the anime PlanetES.

[Anonymous Coward]

Surely an iPad is needed?

If Bury Council think that an iPad is required to ensure the smooth running of garbage collection in Bury then surely an iPad is a fundamental part of any space junk solution? But, strangely, I could find no mention of one in the article.

[Chris Griffin]

Love it

"Asteroids" has become reality. Don't they disappear after three hits?

[Peter Clarke 1]

Simplez

All the Americans need do is get up there in the shuttle, fill the cargo bay and then return to earth. Oh, wait a minute ...

[Rob Carriere]

What we need is...

...Toybox and the Debris section.

[Loyal Commenter]

Shirley...

...when two pieces of orbiting junk cross orbits and collide, the resulting debris ends up in a number of different orbits, most of which will intersect with the Earth's atmosphere? I would have thought that the orbits of most pieces of junk would be decaying anyway, given that space isn't a perfect vacuum in the first place, and most would not be in perfect circular orbits to start with? As mentioned above, does anyone know the lifetime of these orbits? Does the claim of a tipping point really stand up to scrutiny?

[Bango Skank]

Shirley Yes

Yes, little bits coming off won't all share the same orbit as the thing from which they detached, either because they were expelled with force, collided with parts of the craft, picked up some drag, etc.

The orbital decay starts immediately precisely because of what you said - space isn't a perfect vacuum and there are faint forces like sunlight, solar wind, dust, & cetera. The instant it arrives in GEO it is starting its reentry. All of the stuff up there eventually comes down or goes away, depending on what happens to it.

None stays GEO forever.

The time for that decay to result in contact with the atmosphere or the planet can be measured appropriately in seconds, minutes, ... or many hundreds of years.

Yes, tipping point is very apt, and speaks to a probability curve regarding collisions based on population, distribution, and trajectories.

At a certain point the likelihood of a serviceable satellite getting dinged and itself shedding bits becomes high enough to create a chain reaction in exactly the same fashion as that of nuclear fission reactions.

It won't be a domino or arithmetic reaction, but a geometric progression because each collision has a high likelihood of resulting in several more bits of debris.

[John W]

Feedback

We need sticky satellites to introduce some negative feedback so that collisions result in a decrease in junk pieces rather than an increase.

[OrsonX]

Solutions

Sticky satellite.... I like it!

For the small "paint fleck" debris then perhaps something like this could be made to work? Perhaps a giant cylinder or ball with a penetrable outer surface but filled with kinetic absoarbing "kevlar foam". The thing could sweep (literally) across the heavens collecting debris then be directed back into the atmosphere.

Or, how about lazers (with a Zed) to atomise the small bits??

[James 47]

Why NASA only?

Surely the Chinese, Indians and Russians can chip in too?

[Number6]

Retro Games

Obviously one for your old game series - Asteroids. I seem to remember in that, shooting an asteroid resulted in it breaking into lots of smaller ones.

[Lloyd]

Does anyone remember the Tomorrows World on this?

During the 80's? They were talking about sending up a large multilayered disk to try and catch some of it.

[conhoolio]

The solution....

http://en.wikipedia.org/wiki/Asteroids_%28video_game%29

[PassiveSmoking]

Dyson

This is why the vacuum cleaner guy invented the Dyson Sphere, so we would have an enormous vacuum cleaner to suck all the space debris back up without even having to change the bag.

Oh, wait. That's a Dyson Ball.

[Jacqui]

Calling Ben Gunn

and his "space vaccum"!

[mgtrock]

Spaceballs

Megamaid.... simple solution!!

http://local-static2.forum-files.fobby.net/forum_attachments/0020/8567/megamaid-spaceballs_large.jpg

[Anonymous Coward]

Conspiracies!

I don't believe one word they say.

I bet its all a secret conspiracy to create a "spacejunk shield" in order to keep the invading aliens out of our atmosphere!

[Anonymous Coward]

Not to mention

That the Earth is flat.

[Jared Hunt]

Ok I posted too soon, GEO is riskier than I thought

Reading some of the later comments from people in the satellite business shows how much I know. Which clearly isn't all that much. Oh well, every day's a school day.

[Bango Skank]

oh sweet Jeebus! GEO refers to ...

(a) an altitude at which Geosynchrony can be achieved with low additional energy usage i.e. thrusters, AND

(b) the orbits of bodies that have achieved an orbital speed equal to the rotation of the planet regardless of whether they use energy to stay there or not

Now that might sound like it is standing still but actually it means that it is belting along at a massive lick and could clobber anything that crosses its path going in, going out or traversing at any angle to its orbital sphere.

Loads of stuff comes in (literally tons a day) from space and includes things too small for the naked eye to see and things even bigger than Paris's inflatable head.

A fair amount traverses those orbits going up too, things on their way to Mars for example, and often shedding little bits ranging from paint flecks to tools to great big panels as they go.

On top of that, if a geostationary satellite sheds any bits, there is no guarantee that those bits will continue to share the same orbit, and can't start accelerating ever so slowly as they wind downwards back to the planet at ever increasing speeds for ever so long because of drag, collisions, or separation vectors. After many moons of a very modest acceleration some pretty amusing and entertaining velocities can be attained - in the order of many thousands of meters per second.

At which point a paint fleck can punch a rather satisfying hole in a duraluminium plate.

As far as China is concerned, well their response to the weaponization of space and GPS-guided munitions was to hint that (a) they could shoot stuff down if they liked, and (b) if they wanted to they could heave a busload of little ball-bearings up there and put a stop to people guiding things or threatening to launch stuff from up there.

Perhaps one should pay attention to this simple practical demonstration that if you bring your guns and grenades into the pool, they shall crap in it and laugh at you.

[Siduri]

Scientists report that use of the phrase ''tipping point' has reached a tipping point

Scientists report that use of the phrase ''tipping point' has reached a tipping point with more than 100% of circulating word volume now consisting of this phrase. There are now so many instances of this in orbit that they risk colliding with each other and causing damage to the grammatosphere. Boffins are already worried that the huge cloud of circulating instances of 'iconic' have contributed to global hot air. It now seems that excessive use of tipping point means we are all...(continued on p94). Sorry, sorry, couldn't resist. It aint Reg - its the original writers I'm aimed at btw.

[Olafthemighty]

@ Siduri

+1 Internets for "grammatosphere" and another +1 for sneaking an Eye reference in there!

[stu 19]

Space Cleaner

Space cleaner for hire, GBP 7000 per hour. You provide the ship and suit and I'll bring a brush and a bin bag.

[Anonymous Coward]

Big space going vacuam cleaner? Spaceballs!

Been done see Mel Brooks as I believe he and Princess Vespa have the patent.

Behold the Mega Maid.

http://www.youtube.com/watch?v=fffN1Bkd2YQ

[Anonymous Coward]

Sorry, prior prior art

Sorry, but I think Richard Benjamin and "Quark" have prior art to Mr. Brookes....

http://www.imdb.com/title/tt0077066/

[T.a.f.T.]

New Moon

Perhapse we need to build a couple of new artificial moons of a sizable mass just under and above the geostationary area to sweep the skys clean. I am thinking some thing mostly made of rubish with a few limited boosters to keep it in orbit; like a Space Hulk from the 40k universe.

<- Looks a little like an Ork

[Anonymous Coward]

99942 Apophis

I wonder if anyone has taken into account the effect of

a) 99942 Apophis nudging the space junk by gravity and/or more importantly

b) the space junk changing the trajectory of 99942 Apophis, either by gravitational effect or simple impact?

By the time 2029 comes round, we may well have more stuff "up there" to screw around with nature.

[Loyal Commenter]

Here you go:

Additional gravitation pull on debris from 99942 Apophis compared to tidal effects from Moon: 0.0000...%

Additional graviational pull on 99942 Apophis compared to gravitational pull from Earth/Moon system, bearing in mind that the additional mass in orbit originated from said Earth/Moon system: 0%

Proportional of solar system gravitational pull that affects the orbit of 99942 Apophis that comes from the Earth/Moon system, bearing in mind that most of the solar system's mass is concentrated in the sun, then Jupiter, and that 99942 Apophis will only experience any appreciable gravitational pull from the Earth/Moon system when it is (in cosmic terms) very close: 0.0000...%

[Anonymous Coward]

Oh, thank you!!!!

And here I was without a novel basis for my new doomsday cult.

[Stevie]

Bah!

The answer is for a special satellite (and a special payload for the ISS as this method works in any orbit).

The satellite (or ISS Modulette) is loaded with that high-expansion foam they sell at Home DIY centers for making door and window frames bend so the door or window won't close properly.

Once in a likely junk-heavy trajectory the satellite (or ISS modulette) starts forming a big foamy ball of sticky gunk. Once formed to, say, a few fractions of a mile in diameter, the BFBoSG will act as an inelastic target for all this junk, capturing any that impact it nicely. Best of all, it won't knock bits of fthe ISS if it hits it on one of its junk-removing orbits because it's soft and bouncy at the relatively low approach velocities we shall arrange for it by choice of deployment orbit.

Once it is as full of crap as it can get without shattering we de-orbit it over someone we don't like. They'll be picking junk out of their topsoil for years, and that sticky foam is murder to deal with after re-entry has melted it into tar. That'll teach 'em.

This plan offers the following significant advantages:

a) all off-the-shelf technology, no new costly R&D needed.

2) totally green unless you count the places we drop the junkball on after de-orbit, but then, we shall pick the most deserving smug bastards to host the Return of the Satellite Bits so that's all right.

#) gets all those cans of expanding foam off the DIY store shelves so they can't be purchased and deployed by unwitting home handymen, thereby saving the cost of foam-removal-from-windowframes the next day.

I see no downside.

[Chris 244]

Global warming is the solution

The most efficient way to clear out LEO of debris is to warm up our atmosphere. Gas expands upon warming, including the air up there. Bigger atmosphere = more drag in LEO.

[Jonathan Bliss]

I remeber this from about 20 years ago.

I remember this from a few years back.

In 1990 or 1991 I had to give a talk on "anything" as part of a presentation skills course. Not having a clue I picked up the most recent issue of Analog and used an article from that. What to do about space debris before we end up trapped on the planet.

I can't see anyone taking any action until we actually lose a couple of satellites. You'd think New International would be starting to lobby for NASA to go and do something given how much they rely on the technlogy.

[atomic jam]

Magnets

They could stick a giant magnet up there.

[Anonymous Coward]

GEO freeway analogy

All objects in the geosynchronous orbit are travelling the same speed and direction just like cars on a freeway. Obviously collisions are impossible and none of us are ever late for work. The biggest difference between the Clarke Orbit and the freeway however is the lack of medians. There is nothing except satellites stopping objects in other high orbits from "crossing the freeway" in almost any speed or direction (or even driving the whole freeway backwards). If a geostationary satellite does explode into dust, that dust will not (at least not quickly) collect at a La Grange point, as some have suggested but will form a highly variable cloud in an infinite number of orbits with, on average, the orbital energy and momentum of a Clarke Orbit.

[The elephant in the room]

Frikkin Lasers!

The solution to any problem!

[Al 24]

RE: Frikkin Lasers!

And I thought you were just joking!

http://en.m.wikipedia.org/wiki/Laser_broom

[John Smith 19]

@Al 24

Try this

http://www.wikipedia.org/wiki/Laser_broom

[RTNavy]

NEW JOBS:

Domestic Engineer needed, ability to work alone in low gravity work environment. Work clothing and vehicle responsibility of employee!

[Ken Hagan]

Space elevators

The "column" of a space elevator isn't moving (relative to the Earth) fast enough to be in orbit. That's one of the reasons why they are hard to build. Therefore, if anyone ever does manage to erect one, they'll find that for most of its height it is sweeping up objects that *are* in orbit.

Just one more technical hurdle to throw at the space elevator designers then: must be able to withstand collisions with solid objects at several km/s.

[Jared Vanderbilt]

Self regulating problem.

Now that we've reached the point where that anything that gets sent into the LEO gets smashed to bits simple return-on-investment will limit the cost and number of new objects that get sent up. The problem solves itself.

This also remedies the manned space flight dilemma. A protective ring of death keeps humans on the ground (and aliens in space where they belong). And global warming will subside when all the shiny metallic spacecraft are pulverized into a dust cloud and reflect those pesky solar rays back into space.

Hey I have a new theory on Saturn's rings. Where's my Nobel? Barkeep, work that tap a little faster please.

[steve 124]

uninformed

This may sound like a stupid question, but won't this stuff eventually suffer from a decaying orbit and come back in the atmosphere to burn up harmlessly? I'm sure the newer stuff up there is a concern but surely nothing stays up there very long without a boost to keep it in orbit?

[Stuart 25]

Sky Lab anyone?

I thought the earth atmosphere was quite good at cleaning out near earth orbit.

Even the ISS needs regular boosts to stop the atmosphere bringing it back to earth too soon so I'd imagine fragments of broken sats would suffer the same fate.

This may also be the reason that despite billions of years of asteroids smashing into things we have managed to put our current crop of satellites up. This whole story looks like an attempt by someone to get billions spent on their pet project.

If in doubt just do the maths to look at the volume of space we are talking about given the relatively small mass of metal we have managed to get into orbit.

[Remy Redert]

Re: Uninformed

Yes, it will eventually suffer from a decaying orbit and burn up in the atmosphere.

However we'd like to continue spaceflight for the next few thousand years, not get stuck on the planet because there's too much debris in orbit to get there safely. Once debris reaches the tipping point, it's entirely possible that large parts of Earth orbit become nigh impossible to traverse for hundreds if not thousands of years.

[nyelvmark]

If only we could launch Rupert Murdoch into space

...we could solve the problem. All the junk and crud would quickly come to orbit around him, and it would be easy to avoid.

[John Smith 19]

A few notes

The earths atmospheres is the *biggest* force on an object below 1000Km. At 100 statute miles during solar max (Peak of 11 yr-ish sun spot cycle) that was 7 micro g. (E Ring Propellants and pressurization systems). If that's 1 unit gravitational forces on the same object are at 0.061.

And these are *small* objects like paint flecks, which regularly penetrated 2 of the 3 layers of the Shuttle wind shied (BTW AFAIK this is one of those no backup situations which pretty much guarantee LOC)

The top of the Earth's atmosphere can grow or shrink 10x depending on time of year and day.

In GEO satellite drift in a rectangular "box* something like 25 (E/w) by 4 (N/S) Km. They therefor *all* have relative motion as well and if the propellant fails they start to drift out of their box.

If an object is in a wildly varying orbit (apogee >> perigee) it can have a *very* big relative velocity compared to *any* object in a roughly circular orbit anywhere between those limits. You need to keep in mind the *vectors* of the 2 objects. Stable orbit is *mostly* along, little up/down. Cross orbit it's mostly up/down, little bit along -> massive side impact.

Note 100mph -> c44m/s. Speed of sound is 340m/s. Delta v to trigger re-entry can be 10s of m/s. LEO orbital velocity (*along* track) is c7795m/s. You won't like a side impact from that.

They're small and there are *lots* of them, so low scrap value.

I'll note that if you can charge these objects their passage through the Earth's magnetic field *should* create enough drag to get them to do-orbit, while the *very* low atmospheric pressure (yes it's the largest force but by human standards it's virtually a vacuum) would prevent them discharging once charged up.

How you do that is the tricky question.

[kain preacher]

Glue balls

Just launch a few 1000's glues balls into space . Make sure the core is comprised of thermite, oxidizers and solid ox. When the balls gets full blast them with a 750 Tera watt laser . With a bunch of mini suns you can burn every thing up. No I'm not drunc bno I'm not boozed up.

Rick Perry for prez. Runs from the Dr.s it white lab coats.

[Mako]

"No I'm not drunc bno I'm not boozed up."

You sure, mate?

[Coen Dijkgraaf]

"to monitor and tack space debris"?

What clever scientist worked out a way of tacking objects in orbit to the fabric of space?

[CyberCod]

It is time...

...to launch the space magnets.

[gzuckier]

waste not

Dangerous space junk? Or valuable building material for orbital habitats, systematically launched over several decades prior to when it will be needed?

[the Jim bloke]

Geo stationary orbits very valuable real estatte

To achieve a geo stationary orbit there is a very limited altitude range, and specific orbital velocity and path..

the area relevant to europe is desired by anyone from South Africa up to Finland, for Australia, we need to share with Indonesia, Japan, and China.. Merkans dont need to share - anyone in the area just gets their stuff and is supposed to be grateful..

So the satellites that go in GSO are the ones that prevent airplanes from flying into the ground (WAAS) and communications etc.. not enough space for everyone.

Geo synchronous is a bit looser than geo stationary, but still competing for the same area