Two Satellites Collide

[Urwumpe]

It has been reported that this one snapped off after just about 6 months of service.

I had the report that it was considered operational for 5 years, until 1998.

 

[SiberianTiger]

I had the report that it was considered operational for 5 years, until 1998.

No, I was wrong and you were right.

 

[garyw]

Yea, it's not like it costs you a lot of fuel to de-orbit your empty booster or your old satellite. Just let it catch the upper atmosphere and it's done.

And then pay the bill when a metal fuel tank kills someone.

You don't just deorbit a stage anywhere, it has to be done safely.


-----Post Added-----

Good for him.
He's lying.

Of course he is. If there was any truth to it, as a millitary person, He would know to keep his mouth shut.

 

[T.Neo]

And then pay the bill when a metal fuel tank kills someone.

You don't just deorbit a stage anywhere, it has to be done safely.

Wouldn't the impact zone be calculable from atmospheric factors, etc?

 

[Urwumpe]

Wouldn't the impact zone be calculable from atmospheric factors, etc?

You have a more or less huge impact ellipse, even if you have accurate knowledge of the time of reentry.

Just look at the impacts of Skylab, Salyut 7 and Mir:

Skylab: NASA did their best to reduce the damage with the limited possibilities. Got fined for littering in Australia, but did not cause fires.
Salyut 7: No mitigation at all - impacted somewhere on Earth. Somewhere in this case was Argentina. Result had been a few Steaks á la Kosmos 1686.
Mir: Painful coordinated damage mitigation with accurately controlled deorbit. Impact hit target zone. Which was luckily large enough to be hit.

 

[T.Neo]

But the ocean is big, expecially the Pacific. Would that be too hard to miss?

 

[Urwumpe]

But the ocean is big, expecially the Pacific. Would that be too hard to miss?

The pacific is also used for planes and ships - if you want to drop something, you can't just close the whole ocean, you need to limit yourself to a small region and make sure that it is free of suicidal idiots.

 

[T.Neo]

The pacific is also used for planes and ships - if you want to drop something, you can't just close the whole ocean, you need to limit yourself to a small region and make sure that it is free of suicidal idiots.

Then what about diverting shipping lanes and flightpaths, and making a designated "drop zone"?

 

[Urwumpe]

Then what about diverting shipping lanes and flightpaths, and making a designated "drop zone"?

That is already done. But you can't make these drop zones arbitrarily large. If your impact ellipse is so big, that it is impossible to let a plane fly for a day... people will say "Forget it. We will just fly and sue you if you can't keep your things together."

 

[T.Neo]

That is already done. But you can't make these drop zones arbitrarily large. If your impact ellipse is so big, that it is impossible to let a plane fly for a day... people will say "Forget it. We will just fly and sue you if you can't keep your things together."

Darn.
Now, would it cost more to put more propellant in these stages/satillites then it would be to repay those people?

 

[Urwumpe]

Darn.
Now, would it cost more to put more propellant in these stages/satillites then it would be to repay those people?

Kill a human accidentally as huge US government agency, and you will find out.

You better avoid it. Especially if you might kill US citizens. They are expensive targets and have gained a huge target cross section in the last years on the average. Afghans or Somali are cheaper, but harder to hit.

 

[garyw]

Darn.
Now, would it cost more to put more propellant in these stages/satillites then it would be to repay those people?

Over time, Yes.

It's not just repaying them. The vast majority of shipping are international cargo containers which are transporting anything from fruit and veg to cars. A lot of the products spoil quickly and the captains of the cargo ships get bonuses for being early into port. Those bonuses can be a few months money - It's THAT cut throat in the shipping trade.

So, you want to start dumping stages everywhere? That's a lot of people to repay and it will get expensive very quickly. How would you verify those claims? That's also going to get expensive.

Also, What about marine life? Can you imagine the wildlife campainers if your stage whacked the middle of a rare whale breeding area?

 

[T.Neo]

So, you want to start dumping stages everywhere? That's a lot of people to repay and it will get expensive very quickly. How would you verify those claims? That's also going to get expensive.

Also, What about marine life? Can you imagine the wildlife campainers if your stage whacked the middle of a rare whale breeding area?

Even in such a breeding area I would expect the wildlife to be rather widespread.
If I deorbit a rocket stage, and it hits a whale by accident, why make such a fuss over me when other countries kill whales on purpose under the guise of it being "scientific"?

And, if deorbiting this stuff isn't practical, what do you do with it?
Leave it up there with the threat of spalling into minute untrackable debris?

Or, what about collecting this junk and wrapping it up in balls for easy disposal?

 

[TSPenguin]

If you leave stuff up there, you just pushed the problem a few years/decades ahead. It is going to come down eventualy.
So either you invest some kilograms into proper deorbiting stuff now or you take the easy route, leave it up there and just don't care.

 

[T.Neo]

If you leave stuff up there, you just pushed the problem a few years/decades ahead. It is going to come down eventualy.
So either you invest some kilograms into proper deorbiting stuff now or you take the easy route, leave it up there and just don't care.

Exactly. Stuff could come down all over the place...
That would be far more dangerous then a vague ellipse in the Pacific.

 

[Hielor]

You better avoid it. Especially if you might kill US citizens. They are expensive targets and have gained a huge target cross section in the last years on the average. Afghans or Somali are cheaper, but harder to hit.

:rofl::rofl::rofl:

 

[SiberianTiger]

We need to build a space elevator with the cable made of unobtainuium. There's a triple benefit: In a few years, there won't be any space junk; We get a cheap access to space; And finally, we obtain unobtainium! :rofl:

 

[T.Neo]

We need to build a space elevator with the cable made of unobtainuium. There's a triple benefit: In a few years, there won't be any space junk; We get a cheap access to space; And finally, we obtain unobtainium! :rofl:

"Where do you get unobtainium?"
"I don't know, you just build something out of it"
:rofl:

But how exactly does building a space elevator remove space junk?

 

[Linguofreak]

And a more on-topic question - was that collision an observable event?
If they collided at near 8km/s velocity, shouldn't there be a flash or something visible from the ground?

What are the dynamics of such an impact - which plane the pieces are in for example?
Or did the satellites just clipped each other producing a debris field and a couple of noseless derelicts?

According to Wikipedia, the relative velocity was 11.6 km/s. At about 2.9 km/s, an object's kinetic energy is equal to the explosive yield of its mass in TNT. Kinetic energy goes up with the square of velocity. So at 11.6 km/s, the yield equivalent to about 16 times the mass of the colliding objects. The satellites together weighed about 1.5 tons. So your yield is about 24 tons of TNT.

 

[SiberianTiger]

"Where do you get unobtainium?"
"I don't know, you just build something out of it"
:rofl:

But how exactly does building a space elevator remove space junk?

It stretches out from a point on the Equator to a point at GEO. Every orbiting body's track below GEO will eventually cross the cable. And THAT is a usual counter-argument against a viability of a space elevator.