Space junk blues

MrBishop

Well-Known Member


A computer-generated pic of all the crap that's in Earth orbit right now.
What this pic doesn't show is - what the hell we can do about it.

Scientists are keeping a close eye on orbital debris created when two communications satellites one American, the other Russian _ smashed into each other hundreds of miles above Siberia Tuesday Feb. 10, 2009. Think of it as a galactic garbage dump. With a recent satellite collision still fresh on minds, participants at a meeting Thursday Feb. 19, 2009 in the Austrian capital Vienna are discussing ways to deal with space debris junk that is clogging up the Earth's orbit.
Associated Press
 

Professur

Well-Known Member
The density, perhaps...but not the volume of space junk out there.

I'm surprised that there aren't more collisions.

That's because you don't understand just how insanely huge a space (pard'n the pun) you're dealing with. Standard orbit radius gives you an surface area of about four times the surface of the earth. If the entire population of the planet was to be transported en masse to equidistant points, evenly distributed about that area ... you`d never see another person. They'd be too far away. But then, it`s not even a plane, either, but a volume. So you'd need to match not only two dimensions, not even 3, but 4 dimensions to have one single collision.
 

MrBishop

Well-Known Member
That's because you don't understand just how insanely huge a space (pard'n the pun) you're dealing with. Standard orbit radius gives you an surface area of about four times the surface of the earth. If the entire population of the planet was to be transported en masse to equidistant points, evenly distributed about that area ... you`d never see another person. They'd be too far away. But then, it`s not even a plane, either, but a volume. So you'd need to match not only two dimensions, not even 3, but 4 dimensions to have one single collision.
These bits aren't equidistant, nor immobile. Few of the satellites in play are geosynchronous, and certainly none of the space-junk, not bits of damaged satellites.

Most in the 'representation' are large enough to be tracked - most of the pieces of the accident aren't trackable - too damn small - but not so small that they can't badly damage other satellites, the Int'l space station, shuttles etc..should there be an impact.
 

Altron

Well-Known Member
It's very unlikeily for two things to hit... obviously, it happened, but it's not going to happen often.

Those things up there have well defined trajectories with small variations in path. It's not a floating junkyard where things are bouncing off of each other. We've known how to calculate orbital paths for the past 400 years.

I find that picture very hard to believe... if there was that much shit, we would have a noticeable decrease in the intensity of sunlight.

The junk is very high up, and very fast, but it will eventually fall down low enough to get burnt up in the atmosphere. I'm going to guess that most of it dates back to the Space Race, when it was about launching satellites, not keeping them operational.
 

catocom

Well-Known Member
It's very unlikeily for two things to hit... obviously, it happened, but it's not going to happen often.

Those things up there have well defined trajectories with small variations in path. It's not a floating junkyard where things are bouncing off of each other. We've known how to calculate orbital paths for the past 400 years.

I find that picture very hard to believe... if there was that much shit, we would have a noticeable decrease in the intensity of sunlight.

The junk is very high up, and very fast, but it will eventually fall down low enough to get burnt up in the atmosphere. I'm going to guess that most of it dates back to the Space Race, when it was about launching satellites, not keeping them operational.

yeah I don't know if I buy the whole 'out of control' thing.
 

MrBishop

Well-Known Member
It's the most recent hit..but the only one? Hell, not one year ago, the Chinese tested their satellite killer missile on one of their 'non-operating' satellites.
The largest space debris incident in history was the Chinese anti-satellite weapon test on January 11, 2007.[17] The event was estimated to have created more than 2300 pieces (updated 12/13/07) of trackable debris (approximately golf ball size or larger), over 35,000 pieces 1 cm or larger, and 1 million pieces 1 mm or larger. The debris event is more significant than previous anti-satellite tests in that the debris field has a higher orbit altitude, resulting in deorbit times of 35 years and greater

The U.S. Strategic Command maintains a catalogue currently containing about 13,000 objects, in part to prevent misinterpretation as hostile missiles. Observation data gathered by a number of ground based radar facilities and telescopes as well as by a space based telescope[10] is used to maintain this catalogue. Nevertheless, the majority of debris objects remain unobserved. There are more than 600,000 objects larger than 1 cm in orbit (according to the ESA Meteoroid and Space Debris Terrestrial Environment Reference, the MASTER-2005 model)
 

Professur

Well-Known Member
Um, I hardly think that a deliberate targeted killer launch really comes into the conversation of space junk collisions.
 

MrBishop

Well-Known Member
It's not about collisions..it's about space junk and potential damage caused by said orbiting debris. (To satellites, space stations, astronauts on space walks, telescopes like the Hubble and soon to be launched Kepler) etc..

The sat-killer added to the number of orbiting junk...in a big way.
 

Professur

Well-Known Member
It's not about collisions..it's about space junk and potential damage caused by said orbiting debris. (To satellites, space stations, astronauts on space walks, telescopes like the Hubble and soon to be launched Kepler) etc..

The sat-killer added to the number of orbiting junk...in a big way.

Dude, you really need to consider reading what you type. What potential damage is there without collissions ... if it's not about collisions?

And as for the amount of debris .... a large amount of it headed straight down. A large amount headed straight up. Most of what didn't stayed pretty much where the original satelite was anyhow. What went down is going to reenter in short order. What went up ... for every mile up, there's another few hundred billion miles of nothingness for it to exist in a la solo. For what stuck around ... it was going to be there anyhow. The precious little that went sideways is now much smaller and much more subject to the solar wind and photonic pressure (you did know about them, didn't you?) and is the only real increase in debris that matters.
 

MrBishop

Well-Known Member
Dude, you really need to consider reading what you type. What potential damage is there without collissions ... if it's not about collisions?

Um, I hardly think that a deliberate targeted killer launch really comes into the conversation of space junk collisions.

The thread isn't abut collisions (that have already happened), it's about the increased chances of future collisions due to the increasing number of junk in orbit...and what can be done about it.
 

Altron

Well-Known Member
Well, if we stop making new junk, the old junk will fall down.

Prof - the acceleration due to photonic pressure is more of a function of mass and surface area than size. Small, dense particles will have less acceleration than large, light objects.
 

catocom

Well-Known Member
well, if there's enough junk, that takes out more sats, big bro is going
to have a tough time with that.

We need to keep land lines around.
 

Luis G

<i><b>Problemator</b></i>
Staff member
I wonder how mankind was able to put in orbit pieces of junk bigger than a small country :confuse3:
 
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