Pentagon to Shoot down Spy Sat

John wrote:
This is from another group . . . but I got to admit . . . this is just
not passing the sniff test yet.


http://www.latimes.com/news/nationwo...,7685340.story

"The plan calls for firing a tactical missile at the satellite when it
reaches a low orbit of about 130 nautical miles. Officials said Navy
ships would attempt to shoot down the satellite from the northern
Pacific Ocean.
Marine Gen. James E. Cartwright, vice chairman of the Joint Chiefs of
Staff, said the action was not intended to ensure that classified
components on the craft were destroyed before hitting the ground, saying
any sensitive instruments would be destroyed when the satellite
reentered Earth's atmosphere.
"There's some question about the classified side of this," Cartwright
said at a Pentagon news conference announcing the decision. "Once you go
through the atmosphere and the heating and the burning, that would not
be an issue in this case. It would not justify using a missile to take
it and break it up further."
Military commanders conferred with NASA officials to ensure the
operation didn't interfere with the orbiting International Space Station
or space shuttle Atlantis. NASA Administrator Michael Griffin said the
risk posed to either one by the destruction of the satellite was
negligible."

By blowing it apart in low orbit weeks before it would have naturally
decayed, good sized chunks of it will be scattered all over its orbital
path before reentry, so in other words you are actually increasing the
odds of something falling on someone's house by doing this.
Hydrazine is a monopropellant that detonates if heated (as we found out
the hard way on the Contour spacecraft), so if the satellite had fallen
naturally, it almost certainly have exploded at high altitude and dispersed.
The remark about the tank being "well insulated" is interesting... if it
needs to be well insulated, it's on the exterior of the satellite and
exposed to sunlight. That in turn means it would not be sheltered by the
satellite's structure during reentry.
This is almost certainly about the proposed Russo-Chinese space weapons
treaty we rejected two days ago:
http://afp.google.com/article/ALeqM5..._E6fDr_NfYJdCQ

Pat

On Thu, 14 Feb 2008 14:15:49 -0800, in a place far, far away, "Al G"
made the phosphor on my monitor glow in
such a way as to indicate that:


Note the Kinetic Kill Vehicle. With no explosives, this shouldn't scatter
parts to far.

At orbital velocities, explosives are superfluous.

On Thu, 14 Feb 2008 16:21:14 -0600, in a place far, far away, Pat
Flannery made the phosphor on my monitor glow in
such a way as to indicate that:



wrote:
Hear on the afternoon news, not much detail.
Thought I heard them say will use a missle to knock it down to retain
more control. Jeez now we'll have quite a mess up there. I'm sure
there will be more info shortly......................Doc


It's going to be "shot down" {a complete misnomer as it will be broken
up, not shot down) by a missile launched from a Navy cruiser:
http://www.abcnews.go.com/Technology...4292585&page=1
Let's see where all the administration people who were pulling their
hair out over the evil Chinese ASAT test are now.

Our test won't create a debris cloud in LEO that lasts many years.

On Feb 14, 4:21 pm, Pat Flannery wrote:

The evil hydrazine tank will almost certainly cook off during reentry, which makes it only a small threat.

Quite small.

The hazard(*) area on the ground around the 1-meter tank quoted at the
DoD briefing was "two football fields," probably meaning two hectares.
IOW, 1e-10 or less of the surface of the earth underneath the
satellite's orbit: 1/10,000,000,000.

(*) For effects that might cause you to visit your doctor, or worse.

On Feb 14, 5:58 pm, Pat Flannery wrote:

By blowing it apart in low orbit weeks before it would have naturally
decayed, good sized chunks of it will be scattered all over its orbital
path before reentry, so in other words you are actually increasing the
odds of something falling on someone's house by doing this.


incorrect, the pieces would smaller
Hydrazine is a monopropellant that detonates if heated (as we found out
the hard way on the Contour spacecraft),

Wrong. That was known since the early days of the space program and
it was Contour'a SRM that came apart

so if the satellite had fallen
naturally, it almost certainly have exploded at high altitude and dispersed.
The remark about the tank being "well insulated" is interesting... if it
needs to be well insulated, it's on the exterior of the satellite and
exposed to sunlight. That in turn means it would not be sheltered by the
satellite's structure during reentry.

Totally incorrect. You state the exact opposite of what needed.
Exposed to the sun would heat it. Burying it in the structure is the
best place to help insulate it

Al G wrote:

Note the Kinetic Kill Vehicle. With no explosives, this shouldn't scatter
parts to far.


Assuming the hit it head on, impact velocity will be a minimum of around
17,000 mph as the satellite runs into the ascending KKV. That is going
to scatter stuff far and wide, although most of it will descend out of
orbit in fairly short order as the net effect will be to decelerate the
debris.

I believe the N. Koreans will watch with interest.


They don't really need to, as they don't have any satellites.
Who this is aimed at is China and Russia.
And they _will_ take notice, and this bodes no good at all for keeping
weapons out of space.
Apparently there was a good deal of squabbling about this in the
administration, but the White House...read Cheney's crew of ex-Project
For The New American Century* wackos...demanded it be done:
http://www.reuters.com/article/newsO...47206620080214

"U.S. officials said they were not trying to protect classified
information on the satellite or to demonstrate their capabilities to
China, which downed one of its own satellites with a missile last year,
drawing criticism from Washington.
But some experts disagreed and questioned the risks associated with
shooting down the satellite.
Two defense officials also cited disagreement within the administration
over the action and said the decision appears to have been strongly
influenced by the White House."

* Which appears to be pretty much defunct; the website is still there,
but the search engine doesn't work, and the last update was in December
of 2006.

Pat

On Thu, 14 Feb 2008 18:18:52 -0600, in a place far, far away, Pat
Flannery made the phosphor on my monitor glow in
such a way as to indicate that:



Al G wrote:

Note the Kinetic Kill Vehicle. With no explosives, this shouldn't scatter
parts to far.


Assuming the hit it head on, impact velocity will be a minimum of around
17,000 mph as the satellite runs into the ascending KKV. That is going
to scatter stuff far and wide, although most of it will descend out of
orbit in fairly short order as the net effect will be to decelerate the
debris.

No, the net effect will not be to decelerate the debris. The net
effect will be to break it up into smaller pieces of varying orbital
eccentricities, but all of them will come down at least as quickly as
the original satellite would have. That's why it's dumb for the media
to say that we are "shooting it down."

They don't really need to, as they don't have any satellites.

The ability to kill a satellite is at least somewhat correlated with
the ability to kill a missile.

Who this is aimed at is China and Russia.
And they _will_ take notice, and this bodes no good at all for keeping
weapons out of space.

Can you say "unverifiable"? There is no way to keep weapons out of
space. It's not even a good idea, any more than one can keep weapons
out of a school.

On Thu, 14 Feb 2008 18:18:52 -0600, in a place far, far away, Pat
Flannery made the phosphor on my monitor glow in
such a way as to indicate that:



Al G wrote:

Note the Kinetic Kill Vehicle. With no explosives, this shouldn't scatter
parts to far.


Assuming the hit it head on

A poor assumption.

Pat Flannery wrote:



wrote:

Hear on the afternoon news, not much detail.
Thought I heard them say will use a missle to knock it down to retain
more control. Jeez now we'll have quite a mess up there. I'm sure
there will be more info shortly......................Doc



It's going to be "shot down" {a complete misnomer as it will be broken
up, not shot down) by a missile launched from a Navy cruiser:

Let's see where all the administration people who were pulling their
hair out over the evil Chinese ASAT test are now.

At least all of our trash from this will soon reenter. And breaking the
spy sat up should allow it to be pretty much totally destroyed when it
all reenters, so our spy sat secrets won't be blown...


The Soviet RORSATS had a nuclear reactor aboard. When the whole
"dangerous falling satellite" story first broke, I speculated that it
might have one aboard also, and that if they tried to grab it with the
Shuttle or shoot it down, that would reinforce that suspicion.
The evil hydrazine tank will almost certainly cook off during reentry,
which makes it only a small threat.

That hydrazine would be released in space, which is a lot better place
than some random inhabited area on the ground.

The ASAT intercept lets us flex our muscles with the big boys and show
Moscow and Beijing that the eagle still has claws. An interesting
sideline to all this is that it also shows that our ship-launched ABMs
are also ship-launched ASATS, something we never claimed to have or be
developing.



That's for sure. Bit we get to look like good stewards of space, by taking

care of a problem satellite of ours to keep it from killing people

somewheres on the ground. And that the resulting junk would soon reenter,
if it didn't, we'd not have a reason to take out the dead satellite
in the first place...

Brian Thorn wrote:
Except that a reactor would undoubtedly be thick and heavy

No, it doesn't need to be all that heavily shielded, as there's no crew
aboard; check out the one on the Soviet US-A RORSAT:
http://www.svengrahn.pp.se/trackind/RORSAT/RORSAT.html
In that case the reactor proper and its fuel weighed 130 kg, and 385 kg
with its shielding added.
Since the KKV will hit the satellite while its traveling at its orbital
velocity of over 17,000 mph, a tremendous amount of energy will be
liberated in the collision, enough to vaporize or melt a good deal of
its mass.
The way they were talking about it today, the intent is to hit it pretty
much head-on in a way that will cause its debris to lose enough velocity
to reenter and fall into the sea shortly after impact.
I seriously doubt it's going to work like that; more likely pieces of
it are going to get blown all over the place with some maintaining most
of their orbital velocity and still taking weeks to reenter.
As I mentioned earlier, if you just let it come down naturally, the odds
were nearly three out of four that it would come down over the
ocean...by blowing it up, you are going to create debris of different
sizes, mass, and air drag that are going to be descending over a period
of days or weeks, and you can virtually guarantee that some are going to
come down over land.
I think they had blowing it up in mind right from the moment they
"leaked" the info about the dangerous satellite to the press a few weeks
ago, and the proposed Chinese-Russian space weapons treaty we dismissed
two days ago was the thing they'd been waiting for to destroy the
satellite and show the bad guys who's boss.

and
unlikely to be damaged much by an ASAT. Without the rest of the
satellite around it creating drag, a thick, dense reactor will stay up
*longer* not come down faster.


If I were of a conspiratorial turn of mind, I'd say that the satellite
was launched specifically so we could do a ASAT test on it while having
"plausible deniability" about the whole thing. The timing is sure right
in regards to our ABM program, and in the past few days Russia warned
Ukraine that if it starts to deploy any part of a US ABM system (the one
that is supposed to be limited to Poland and the Czech Republic) or put
NATO bases on its territory, it's going to be in deep trouble.
What would be funny is if they shoot at it...and completely miss. :-)

Pat