Satellite defense

I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?
Considering that a satellite is probably the same temp as the
background, a tracking device on an asat wouldn't be IR but would be
radar. How easy is it to radically reduce the radar cross section of
future sats considering the need for the antennae etc.
A radar decoy should be easy to put on sats that could be deployed
when it was attacked and then reeled back in for further use.
If we want to protect existing expensive sats, perhaps the use of small
cheaper sats that will be flown to nearby an existing sat that could
deploy a radar reflector when needed would help.
Is Oberg's discussion of the inverse power law for radar really a
limitation for an attack on high flying sats? Wouldn't the initial
target acquisition be done by high power ground based radar and then
final guidance switched over to the kill veh when it gets within range?
Low inclination sats approach China and Taiwan from the west, does this
mean that ship mounted anti-missile systems would be useless for
defending these sats from an attack?
An active sat defense wouldn't suffer from the fourth power radar
problem since it would only need to detect the asat on board radar so
it could respond before the asat got a last fix. Any thoughts on such
active defense?

Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that
is aiming to hit it. Since most spysats are big and heavy and most
ASATs are
small and very quick-footed, it would appear that most ASATs would
prevail in a
one-on-one contest. If not on the first shot, then on the next pass,
or the pass
after that. But if the spysat can deploy decoys or employ other means
to blind
the ASAT sensors before maneuvering, then the ASAT has a more difficult

problem to solve.

- Ed Kyle

On 22 Jan 2007 12:09:08 -0800, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that
is aiming to hit it. Since most spysats are big and heavy and most
ASATs are
small and very quick-footed, it would appear that most ASATs would
prevail in a
one-on-one contest. If not on the first shot, then on the next pass,
or the pass
after that.

That assumes that it gets a second chance. The one that the Chinese
fired was almost certainly suborbital.

Rand Simberg wrote:
On 22 Jan 2007 12:09:08 -0800, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that
is aiming to hit it. Since most spysats are big and heavy and most
ASATs are
small and very quick-footed, it would appear that most ASATs would
prevail in a
one-on-one contest. If not on the first shot, then on the next pass,
or the pass
after that.

That assumes that it gets a second chance. The one that the Chinese
fired was almost certainly suborbital.

Right. But a determined attacker would probably assign several ASAT
missiles to a specific target. They could be fired on sequential
passes
if the first one misses. Either the presumably mobile missiles could
be
lined up beneath multiple orbit tracks, or the attacker could simply
wait
12 or 24, or however many, hours.

- Ed Kyle

Ed Kyle wrote:
Rand Simberg wrote:
On 22 Jan 2007 12:09:08 -0800, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that
is aiming to hit it. Since most spysats are big and heavy and most
ASATs are
small and very quick-footed, it would appear that most ASATs would
prevail in a
one-on-one contest. If not on the first shot, then on the next pass,
or the pass
after that.

That assumes that it gets a second chance. The one that the Chinese
fired was almost certainly suborbital.

Right. But a determined attacker would probably assign several ASAT
missiles to a specific target. They could be fired on sequential
passes
if the first one misses. Either the presumably mobile missiles could
be
lined up beneath multiple orbit tracks, or the attacker could simply
wait
12 or 24, or however many, hours.

Yes, if you have a large number of ASAT interceptors, you can probably
be assured of destroying one or a few particular satellites. But a
large number of ASAT interceptors take money and time to build. Also,
once you try to destroy a billion dollar military asset of a foreign
country and fail, you have put yourself in an undesireable situation.
The owner of the satellite may decide to destroy a few billion dollar
military assets of yours, on the "do unto the other guy what he would
do unto you, but do it unto him first" theory. Some obvious
hard-to-hide choices are space surveillance radars and satellite launch
complexes.

- jake

Jake McGuire wrote:
Ed Kyle wrote:
Rand Simberg wrote:
On 22 Jan 2007 12:09:08 -0800, in a place far, far away, "Ed Kyle"
made the phosphor on my monitor glow in such a
way as to indicate that:

Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that
is aiming to hit it. Since most spysats are big and heavy and most
ASATs are
small and very quick-footed, it would appear that most ASATs would
prevail in a
one-on-one contest. If not on the first shot, then on the next pass,
or the pass
after that.

That assumes that it gets a second chance. The one that the Chinese
fired was almost certainly suborbital.

Right. But a determined attacker would probably assign several ASAT
missiles to a specific target. They could be fired on sequential
passes
if the first one misses. Either the presumably mobile missiles could
be
lined up beneath multiple orbit tracks, or the attacker could simply
wait
12 or 24, or however many, hours.

Yes, if you have a large number of ASAT interceptors, you can probably
be assured of destroying one or a few particular satellites. But a
large number of ASAT interceptors take money and time to build. Also,
once you try to destroy a billion dollar military asset of a foreign
country and fail, you have put yourself in an undesireable situation.
The owner of the satellite may decide to destroy a few billion dollar
military assets of yours, on the "do unto the other guy what he would
do unto you, but do it unto him first" theory. Some obvious
hard-to-hide choices are space surveillance radars and satellite launch
complexes.

- jake

Yes. So much would be at stake that I don't think we would
see ASAT attacks unless a big war was already on, or was
just about to begin. China's main wargaming scenario has
to be Taiwan, where it would need to blind the U.S. for just a
few days. Once they have swarmed onto that island, and
have it surrounded by a gazillion submarines and protected
by a missile screen, the war is over.

- Ed Kyle

On 22 Jan 2007 12:09:08 -0800, "Ed Kyle" wrote:

If not on the first shot, then on the next pass, or the pass
after that.

They'll only get the one chance. After that, they'll have to start
heading to their bunkers because the B-2's are a-comin'...

Brian

Brian Thorn wrote:
On 22 Jan 2007 12:09:08 -0800, "Ed Kyle" wrote:

If not on the first shot, then on the next pass, or the pass
after that.

They'll only get the one chance. After that, they'll have to start
heading to their bunkers because the B-2's are a-comin'...

Brian

I doubt that any nation would attack another's satellites
unless the war had already begun. There would be no
point otherwise.

I agree that a full scale missile war won't last very
long.

- Ed Kyle

Ed Kyle wrote:
Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that is aiming to hit it. Since most spysats are big and heavy and
most ASATs are small and very quick-footed, it would appear that most
ASATs would prevail in a one-on-one contest. If not on the first shot,
then on the next pass, or the pass after that. But if the spysat can
deploy decoys or employ other means to blind the ASAT sensors before
maneuvering, then the ASAT has a ore difficult problem to solve.

Stealth is another potential solution. Misty 1 and 2, launched in 1990
and
1999, respectively, are believed to be KeyHole class IMINT sats, with
radar and optical signature suppression. A new generation is believed
to
be under development.

Misty's stealth technology is believed to be very expensive, so there
is
some question of cost-effectiveness for all but the costliest payloads,
i.e. KeyHoles, but not DMSPs.

Misty's high cost may be a result of the design requirement to always
hide
when in range of an adversary's radar and optical sensors. That may be
ideal for reconnaissance, but perhaps for evading ASATs it would be
sufficient to remain visible except during periods of tension between
the
U.S. and potential attackers. I do not know whether or not that would
be
any less expensive to achieve.

Ted Molczan

wrote:
Ed Kyle wrote:
Frogwatch wrote:
I vaguely remember that some US survelliance sats have the ability to
maneuver. Is this sufficient to dodge a hit to kill asat?

The satellite would have to have more maneuvering capability than the
ASAT that is aiming to hit it. Since most spysats are big and heavy and
most ASATs are small and very quick-footed, it would appear that most
ASATs would prevail in a one-on-one contest. If not on the first shot,
then on the next pass, or the pass after that. But if the spysat can
deploy decoys or employ other means to blind the ASAT sensors before
maneuvering, then the ASAT has a ore difficult problem to solve.

Stealth is another potential solution. Misty 1 and 2, launched in 1990
and
1999, respectively, are believed to be KeyHole class IMINT sats, with
radar and optical signature suppression. A new generation is believed
to
be under development.

As is altitude. Buried in Pete Worden's address to a roomful of
skeptical astronomers at the recent meeting on "Astrophysics
Enabled by the Return to the Moon" was the statement that
current developments in reconnaissance satellite technology
include "slow" adaptive optics, which can make up for what
we;d normally consider underperforming mirror supports structures.
Their rationale is that this lets them think about 30m
mirrors in geosynchronous orbit. (This came up in the context
of ways astronomers can reuse technology that someone else paid
to develop, historicaly a very useful pattern). His talk
is archived at http://www.stsci.edu/center/informat...g/archive/AERM
(near the end of the conference program).

Bill Keel