Re: US: Broken satellite will be shot down

beausabre wrote:
On Feb 14, 9:27 pm, Billy <B...@xxxxxxxxxxxx's> wrote:
Harry Andreas wrote:
In article <fp2392$ru...@xxxxxxxxxxxxxxxxxx>, news <n...@xxxxxxxxx> wrote:
By LOLITA C. BALDOR, Associated Press Writer 1 hour, 5 minutes ago
WASHINGTON - The Pentagon is planning to shoot down a broken spy
satellite expected to hit the Earth in early March, The Associated Press
has learned.
U.S. officials said Thursday that the option preferred by the Bush
administration will be to fire a missile from a U.S. Navy cruiser, and
shoot down the satellite before it enters Earth's atmosphere.
The officials spoke on condition of anonymity because the options will
not be publicly discussed until a later Pentagon briefing.
The disabled satellite is expected to hit the Earth the first week of
March. Officials said the Navy would likely shoot it down before then,
using a special missile modified for the task.
Other details about the missile and the targeting were not immediately
available. But the decision involves several U.S. agencies, including
the National Security Agency, the Department of Homeland Defense and the
State Department.
Shooting down a satellite is particularly sensitive because of the
controversy surrounding China's anti-satellite test last year, when
Beijing shot down one of its defunct weather satellites, drawing
immediate criticism from the U.S. and other countries.
A key concern at that time was the debris created by Chinese satellite's
destruction -- and that will also be a focus now, as the U.S. determines
exactly when and under what circumstances to shoot down its errant
satellite.
The military will have to choose a time and a location that will avoid
to the greatest degree any damage to other satellites in the sky. Also,
there is the possibility that large pieces could remain, and either stay
in orbit where they can collide with other satellites or possibly fall
to Earth.
It is not known where the satellite will hit. But officials familiar
with the situation say about half of the 5,000-pound spacecraft is
expected to survive its blazing descent through the atmosphere and will
scatter debris -- some of it potentially hazardous -- over several hundred
miles. The officials spoke on condition of anonymity because of the
sensitivity of the matter.
The satellite is outfitted with thrusters -- small engines used to
position it in space. They contain the toxic rocket fuel hydrazine,
which can cause harm to anyone who contacts it.
'Ol Lolita apparently doesn't know much about satellites and didn't bother
to learn.
1] You can't "shoot down" a satellite. You can shoot it and destroy it,
but there's no "down" involved. The pieces stay in orbit until they
decelerate enough to re-enter on their own
2] You would think she would correlate the "shoot down" since she
explicitly discusses the China test and all the debris that's STILL in
orbit
3]You would think she would discuss the impact (no pun intended)
of exactly when to shoot the missile, since the satellite is decelerating
and descending on it's own, and shooting it after it's started re-entry will
ensure that the debris will re-enter immediately as well
4] You would think she would discuss the good thing about destroying the
satellite is that breaking it up into smaller pieces will reduce the possibility
of pieces surviving and hitting the ground
5] The chances of hydrazine surviving the "blazing descent through the
atmosphere" are slim at best
I guess that's the problem with journalism degrees.
I remember combining hydrazine and nitromethane for dragster fuel many
years ago. It made many new record runs. Only problem aside from hand
grenading engines was that once the stuff stopped or neared completion
of its chemical combining it became a class a explosive, when vapors an
fizzing stopped from the tank vent. The stuff was nasty but I don't
remember it being a real big deal by itself for toxicity. You would want
to wash in it or drink a glass of the stuff for sure though.

SNIP

"Hydrazine monopropellant thrusters consist simply of an electric
solenoid valve, which allows pressurised hydrazine to enter the engine
as a spray, a catalytist bed of alumina pellets impregnated with
iridium (such as Shell Oil Company's Shell 405), and an expansion
nozzle. These engines typically have twice the thrust-to-weight ratio
of MMH/N2O4 bipropellant thrusters, although monopropellant thrusters
range from three times lighter to being of equal weight for a given
thrust (the thrusters listed in the 100-150 N range were of equal
T:W).

"UDMH (Unsymetrical Dimethyl Hydrazine)is often used in hypergolic
rocket fuels as a bipropellant in combination with the oxidiser
nitrogen tetroxide and less often with IRFNA or liquid oxygen. UDMH is
a derivative of hydrazine and can be called a hydrazine also. As a
fuel, it is described in specification MIL-D-25064.

UDMH is storable and can be kept loaded in the rocket fuel system for
long periods. However it is toxic and tends to absorb through skin. It
has high density and high cost. It is used in virtually all storable
liquid rocket engines. In some applications, eg. some maneuvering
engines, monomethylhydrazine is used instead for its slightly higher
specific impulse.

UDMH has higher stability than hydrazine, especially at elevated
temperatures, and can be used as its replacement or together in a
mixture. UDMH is used in many European, Russian, Indian and Chinese
rocket designs. The Titan, GSLV and Delta rocket families use a
mixture of 50% hydrazine and 50% UDMH, called Aerozine 50.


Biological Effects

Hydrazine is a dangerous, although non-cumulative poison, is corrosive
to eyes, skin, and mucuous membranes, and is a probable human
carcinogen. Its reducing effects make it extremely destructive to
tissues, and it has a variety of adverse systemic effects. Monomethyl
hydrazine has a half-life of 2 days in the environment, and does not
bioaccumulate.

Caustic burns to the skin are the immediate result of contact with the
liquid. Hydrazine dissolves hair, and causes caustic-like burns on
skin.

The vapour is extremely irritating to the eyes and temporary blindness
can result, and eye contact with the liquid causes burns and possibly
permanent damage. Flushing with large quantities of water for 15
minutes is the recommended treatment.

Vapours cause irritation to the nose, throat, and respiratory tract.
High concentrations cause spasm, inflammation, chemical pneumonitis,
and pulmonary edema, and coma in humans, being fatal to half of rats
exposed for four hours at 570 ppm and half of mice at 252 ppm. Other
symptoms of exposure may include a burning sensation, coughing,
wheezing, laryngitis, shortness of breath, headache, nausea, and
vomiting. Symptoms from chronic, nonacute exposure include lethargy,
vomiting, itching and burning sensations, tremors, conjunctivitis, and
contact dermititis.

Readily absorbed through the skin, it can inhibit certain enzyme
systems causing reduced body metabolism. Other systemic effects may
include damage to liver, kidneys, nervous system, and red blood cells.
For skin contact with rabbits, its LD-50 is 91 mg/kg, and with guinea
pigs it is 190 mg/kg. For acute oral doses with rats, its LD-50 is 60
mg/kg, and with mice it is 59 mg/kg.

Hydrazine has a fishy or ammonia-like odor detectable at a mean of 3.7
ppm. The normal 8-hour OSHA permissible exposure limit (PEL) is 1 ppm,
and the immediately dangerous to life and health (IDLH) value is 50
ppm. Hydrazine can be detected in the blood of exposed individuals.

Recommended safe levels for hydrazine's carcinogenic properties are
far lower than those of biological effects stemming from chemical
properties. EPA Cancer Risk Level (1-in-a-million excess lifetime
risk) is 2.0 x 10-73. The EPA suggests that air containing 0.02 mg/m3
of hydrazine directly increases cancer risks by 1 part in ten
thousand.

The chemical is not considered to have adequate warning properties.
Hydrazine detectors, similar to ammonia detectors, are used where the
chemical is handled, and detector cards are used which discolour in
the presence of hydrazine."

Nasty stuff




From Wikipedia



UDMH is storable and can be kept loaded in the rocket fuel system for
long periods. However it is toxic and tends to absorb through skin. It
has high density and high cost. It is used in virtually all storable
liquid rocket engines. In some applications, eg. some maneuvering
engines, monomethylhydrazine is used instead for its slightly higher
specific impulse.

UDMH has higher stability than hydrazine, especially at elevated
temperatures, and can be used as its replacement or together in a
mixture. UDMH is used in many European, Russian, Indian and Chinese
rocket designs. The Titan, GSLV and Delta rocket families use a
mixture of 50% hydrazine and 50% UDMH, called Aerozine 50.

Apart from its use as rocket fuel, UDMH is a nitrogen source in
metalorganic vapour phase epitaxy thin-film deposition.

Safety

UDMH is toxic, a carcinogen and can explode in the presence of
oxidisers."

Here's info on "Hydrazine"

Biological Effects

Hydrazine is a dangerous, although non-cumulative poison, is corrosive
to eyes, skin, and mucuous membranes, and is a probable human
carcinogen. Its reducing effects make it extremely destructive to
tissues, and it has a variety of adverse systemic effects. Monomethyl
hydrazine has a half-life of 2 days in the environment, and does not
bioaccumulate.

Caustic burns to the skin are the immediate result of contact with the
liquid. Hydrazine dissolves hair, and causes caustic-like burns on
skin.

The vapour is extremely irritating to the eyes and temporary blindness
can result, and eye contact with the liquid causes burns and possibly
permanent damage. Flushing with large quantities of water for 15
minutes is the recommended treatment.

Vapours cause irritation to the nose, throat, and respiratory tract.
High concentrations cause spasm, inflammation, chemical pneumonitis,
and pulmonary edema, and coma in humans, being fatal to half of rats
exposed for four hours at 570 ppm and half of mice at 252 ppm. Other
symptoms of exposure may include a burning sensation, coughing,
wheezing, laryngitis, shortness of breath, headache, nausea, and
vomiting. Symptoms from chronic, nonacute exposure include lethargy,
vomiting, itching and burning sensations, tremors, conjunctivitis, and
contact dermititis.

Readily absorbed through the skin, it can inhibit certain enzyme
systems causing reduced body metabolism. Other systemic effects may
include damage to liver, kidneys, nervous system, and red blood cells.
For skin contact with rabbits, its LD-50 is 91 mg/kg, and with guinea
pigs it is 190 mg/kg. For acute oral doses with rats, its LD-50 is 60
mg/kg, and with mice it is 59 mg/kg.

Hydrazine has a fishy or ammonia-like odor detectable at a mean of 3.7
ppm. The normal 8-hour OSHA permissible exposure limit (PEL) is 1 ppm,
and the immediately dangerous to life and health (IDLH) value is 50
ppm. Hydrazine can be detected in the blood of exposed individuals.

Recommended safe levels for hydrazine's carcinogenic properties are
far lower than those of biological effects stemming from chemical
properties. EPA Cancer Risk Level (1-in-a-million excess lifetime
risk) is 2.0 x 10-73. The EPA suggests that air containing 0.02 mg/m3
of hydrazine directly increases cancer risks by 1 part in ten
thousand.

The chemical is not considered to have adequate warning properties.
Hydrazine detectors, similar to ammonia detectors, are used where the
chemical is handled, and detector cards are used which discolour in
the presence of hydrazine."

Nasty stuff


Shows how dumb drag racers were, I guess.
.

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