Experts Scoff at Satellite Shoot-Down Rationale

On Feb 15, 1:41 pm, Jack Linthicum <jacklinthi...@xxxxxxxxxxxxx>
wrote:
On Feb 15, 1:39 pm, "La N" <nilita2004NOS...@xxxxxxxxx> wrote:



"Jack Linthicum" <jacklinthi...@xxxxxxxxxxxxx> wrote in message

news:ea435a13-4fdc-464e-a4f0-0490bd7394eb@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx

On Feb 15, 1:02 pm, "La N" <nilita2004NOS...@xxxxxxxxx> wrote:
"Jack Linthicum" <jacklinthi...@xxxxxxxxxxxxx> wrote in message

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On Feb 15, 12:35 pm, j...@xxxxxxxxx (John Dallman) wrote:
In article <47b5e533.106252...@xxxxxxxxxxxxxxxxxx>,
fairwa...@xxxxxxxxx

(Derek Lyons) wrote:
Why do they build them so sturdy?

Remember, these tanks are built to contain pressurized gas in the
first place! :) Seriously, pretty much any tank is going to fail
at
a single point - and once it does, pressure and thus stress drops
off.
It takes pretty serious overpressure to burst 'em like a cherry
bomb,
and gradual heating leads to a gradual pressure rise.

Also, these tanks tend to be inside the structure, which shields
them
from the worst of re-entry heat. Attached piping also provides
potential failure-and-vent paths, and tends to run much closer to
the
skin (in the case of tanks for RCS systems).

How much of the contents is typically still inside them when they
reach
the ground? Hydrazine's boiling point is only 387K, according to the
data book, so it could do quite a bit of boiling off fairly readily,
once the tank or pipes are breached.

I'm asking these questions because I have two guys - you and a chap
with
a master's in satellite comms and satellite operation experience - who
both seem to know what they're talking about, but are telling me
almost
completely different things about the likely hazard from a re-entering
hydrazine tank.

--
John Dallman, j...@xxxxxxxxx, HTML mail is treated as probable spam.

That sounds like the Pentagon's little trio briefing the other day:
this tank will survive and it is filled with deadly hydrazine which
you should respect as a volatile substance. But, there's no danger if
you keep at least twofootballfields distant from it.

I heard the "twofootballfields" reference on CBC Radio.

Aren't Canadianfootballfields longer than U.S.ans?

Yes. And that's what confused me. I don't know how far away from this
falling debris I should be. In any case, if there is a G*d, the satellite
is falling on Eugene's roof.

The General said to think of it as the size of a bus. This raises a
question since there are various sized buses.


Apparently, the space experts are chiming in on the dangers or lack
thereof, "comedic gold" is the term used. Having the US government
spend millions of dollars to destroy a billion-dollar failure to save
zero lives is comedic gold."

"Everything they said made sense except for the reason for doing the
intercept in the first place."


Experts Scoff at Satellite Shoot-Down Rationale
By Noah Shachtman

February 15, 2008 | 1:14:09 PM


The Pentagon says it has to shoot down a malfunctioning spy satellite
because of the threat of a toxic gas cloud. Space security experts
are calling the rationale "comedic gold."

Yesterday, Deputy National Security Advisor James Jeffrey said the
satellite's tank full of hydrazine rocket propellant was the main
reason the military was planning to blast the orbiter. There's a
small but real risk that the hydrazine tank could rupture, releasing a
"toxic gas" over a "populated area," causing a "risk to human life."

But, as we noted yesterday, Joint Chiefs of Staff Vice Chairman Gen.
James Cartwright cast the threat from the satellite in much less dire
terms. Even if the hydrazine were released, he noted, the effects
would likely be mild -- akin to chlorine gas poisoning, which can
cause burning in the lungs, and elsewhere. The area affected would be
"roughly the size of two football fields [where you might] incur
something that would make you go to the doctor."

And that doesn't sound like much of a risk at all.

Especially when you consider that several other hydrazine-filled
object have come crashing down to Earth. Not only did the space
shuttle Columbia have a similar tank, which survived re-entry, with no
toxic gas cloud. Several other hydrazine-laced objects have also
crashed into the atmosphere, with no ill effects. Space researcher Ed
Kyle notes that there were 42 major reentry objects for 2007,
including 9 satellites -- at least one of which contained a form of
hydrazine, UMDH (unsymmetrical dimethylhydrazine).

In addition, roughly 8-12 upper stages that originally contained
UDMH reentered during 2007. Some of these could very well have
contained some residual propellant. [One particular] upper stage
probably contained several hundred [kilograms] of residual propellant,
for example.

Which leads one military satellite observer to tell DANGER ROOM,
"Everything they said made sense except for the reason for doing the
intercept in the first place."

"The hydrazine tank is a 1-meter sphere containing about 400 liters of
hydrazine. The stated hazard area is about 2 hectares, something like
1/10,000,000,000 of the area under the orbit," he adds. The potential
for actual harm in unbelievably small. Which means the hydrazine
rationale just doesn't hold up, literally not within orders of
magnitude."

"The cynic in me says that the idea that this is being done to protect
the lives of humans is simply a feel-good cover story tossed to the
media," another veteran space security specialist adds. "It is true
that hydrazine is very toxic and could result injury or death, but the
odds of this happening are minuscule. The average person in American
is many thousands of times more likely to be killed in a car accident
than by any falling debris. In fact, no one has ever been killed by
space debris (I have heard of one or two being struck but only minor
injuries). So pretty much everything else you can think of (including
getting hit by an asteroid/comet) is many times more likely than dying
from this. Having the US government spend millions of dollars to
destroy a billion-dollar failure to save zero lives is comedic gold."

"There has to be another reason behind this," said Michael Krepon, co-
founder of the Henry L. Stimson Center, tells the Washington Post. "In
the history of the space age, there has not been a single human being
who has been harmed by man-made objects falling from space."

So what could that other reason be?

Our veteran space security specialist believes there are several. To
him, the satellite shot is a chance for the military to try out its
missile defense capabilities; a way to keep secret material out of the
wrong hands; and a warning to the Chinese, after they destroyed a
satellite about a year ago. He shared some educated guesses:

My first thought is that MDA [Missile Defense Agency] is always
looking for ways to pimp their systems and provide further
justification that they work. The upcoming change in Administration
is almost guaranteed to result in missile defense losing the top-level
advocacy that it has enjoyed for the last several years. Any
additional missions and justifications that the missile defense
community can provide would increase the likelihood of their systems
(and budgetary power) surviving.

An additional reason could be that destroying the satellite would
prevent any chance of another nation getting access to any of the
potentially sensitive technology on board. However, I have heard from
other sources that supposedly the NRO [National Reconnaissance Office
- the country's spy satellite shop] is actually against the
"shootdown" (and I hate that term - the satellite is not flying and is
coming down regardless of whether or not it gets hit by a missile).
Their absence at the press briefing could lend some weight to this
rumor, although it could also be explained by the nature of the
satellite and its still classified link to the NRO.

My real concern is that this is simply a knee-jerk reaction made by
the Administration in response to the purported threat by the Chinese.
Since the April 2007 ASAT [anti-satellite] test, there have been
rumors and whispers going around that the Administration and like-
minded individuals are looking for more sticks (instead of carrots) to
use against China. While this "shoot down" is not a direct action
against China, it would be a clear signal that the US can possess an
active ASAT capability at any time if it so desires. That is a
serious development as the previous US ASAT system using F-15s was
mothballed in the 1980's.

There are many significant political ramifications that would happen
as a result of this. The US has been berating the Chinese on their
ASAT test but now demonstrate that it is okay as long as it occurs at
a low enough altitude to prevent long-lasting debris and can "save
lives". This is close to an implied "ok" for the US and other nations
to conduct more ASAT tests, which could open another arms race. I am
also certain that Russian and China would also see this as a slap in
the face as they are trying to revive the Peaceful Uses of Outer Space
treaty discussion and ban on space weapons. It would further
negatively affect the relations between them and the US. Which could
lead to increased tensions, arms buildup, etc etc etc. Nothing good
for anyone outside of arms manufacturers and politicians that need a
bogeyman to scare people into voting for them.

Oh, and [NASA Adminsitrator Mike] Griffin's presence at the briefing
was also an indicator to me that they are trying to spin this as a
safety issue and not a missile defense / ASAT test. NASA has
absolutely nothing to do with US Strategic Command using a Navy
missile to blow up a broken NRO satellite. This is a military/national
security op from the start and the only reason you trot the NASA
Administrator out is to try and convince people otherwise.

http://blog.wired.com/defense/2008/02/fishy-rationale.html
.

Relevant Pages

  • Re: Experts Scoff at Satellite Shoot-Down Rationale
    ... once the tank or pipes are breached. ... hydrazine tank. ... reason the military was planning to blast the orbiter. ... My first thought is that MDA [Missile Defense Agency] is always ...
    (sci.military.naval)
  • Re: US: Broken satellite will be shot down
    ... WASHINGTON - The Pentagon is planning to shoot down a broken spy ... satellite expected to hit the Earth in early March, ... They contain the toxic rocket fuel hydrazine, ... However it is toxic and tends to absorb through skin. ...
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  • Re: WHATS NEW Robert L. Park Friday, 15 Feb 08, Washington, DC
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  • Re: US: Broken satellite will be shot down
    ... satellite expected to hit the Earth in early March, ... I remember combining hydrazine and nitromethane for dragster fuel many ... "UDMH is often used in hypergolic ... However it is toxic and tends to absorb through skin. ...
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