US Space Weapons Statement

Greetings.

The below article is in reference to debris problems in LEO orbit being
caused by US space weapons and denial of any problems.

http://www.defencetalk.com/news/publ...e_001896.shtml

Can someone clarify some of the responses given by US defense.

Namely, they claim that the Space station can maneuver out of the way of
debris. I understood that ISS could do that for debris it tracks, not small
clouds of debris. What is the smallest size debris tracked by ISS, or are
they dependant on terristrial facilities in the 10cm+ size.

Secondly, they state that debris would likely reenter after one orbit. Is
this accurate. I would have though debris capable of hitting the ISS would
orbit significantly more than once.

Appreciate any clarification.

In article , Christian Ramos
wrote:

The below article is in reference to debris problems in LEO orbit being
caused by US space weapons and denial of any problems.
....
Secondly, they state that debris would likely reenter after one orbit. Is
this accurate. I would have though debris capable of hitting the ISS would
orbit significantly more than once.

In hypervelocity impacts, where thing A hits thing B at several km/s,
you tend to get two clouds of debris that move along the original paths
of A and B. If both A and B are in sub-orbital trajectories before the
collision (like an ICBM and probably the interceptor) then so will the
debris clouds.

A sub-orbital trajectory is just an orbital path where the orbital
ellipse intersects the surface of the Earth. Its highest point can be
well above the height of something that is continuously orbiting, like
the space station. A sub-orbital trajectory can go straight up and
straight down, standing still at the top. A circular orbit goes around
and around very fast (~7 km/s for LEO), and has a kinetic energy from
its motion much larger than its kinetic energy from its height above
Earth's surface.

--
David M. Palmer (formerly @clark.net, @ematic.com)

"David M. Palmer" wrote in message
...
In article , Christian Ramos
wrote:

The below article is in reference to debris problems in LEO orbit being
caused by US space weapons and denial of any problems.
...
Secondly, they state that debris would likely reenter after one orbit.
Is
this accurate. I would have though debris capable of hitting the ISS
would
orbit significantly more than once.

In hypervelocity impacts, where thing A hits thing B at several km/s,
you tend to get two clouds of debris that move along the original paths
of A and B. If both A and B are in sub-orbital trajectories before the
collision (like an ICBM and probably the interceptor) then so will the
debris clouds.

Sure but that is not what the article is talking about. Both A and B will
not be in sub-orbital trajectories. The weapon will be based in space at
orbital velocity. Given that impact is likely to be above the atmosphere,
wouldnt that tend to make some of the debris assume a orbital or close to
orbital speed. As such, would not a large amount of debris follow the
original orbital track but with a perigree slightly closer to the earth than
the original launch platform and an apogee slightly higher than the launch
platform.

A sub-orbital trajectory is just an orbital path where the orbital
ellipse intersects the surface of the Earth. Its highest point can be
well above the height of something that is continuously orbiting, like
the space station. A sub-orbital trajectory can go straight up and
straight down, standing still at the top. A circular orbit goes around
and around very fast (~7 km/s for LEO), and has a kinetic energy from
its motion much larger than its kinetic energy from its height above
Earth's surface.

Hmm.. I'm confused, isnt sub-orbital simply an object moving at less than
orbital speed, example something going straight up and down without any
horizontal velocity. I thought what you were describing was an eliptical
orbit with perigree on the earth's surface. I understood anything could have
such an orbit, including something travelling at orbital speed (although it
wouldnt be orbiting for long ).

I can see where you are going if both A and B are suborbital, but not
launched from an orbital platform to impact with a slightly lower orbit.
Additionally, if an object was hit at a lower orbit than the launching
platform, wouldnt the apogee of some of that debris be in a higher orbit
than the launching platform.

In article , Christian Ramos
wrote:

"David M. Palmer" wrote in message
...
In article , Christian Ramos
wrote:

The below article is in reference to debris problems in LEO orbit being
caused by US space weapons and denial of any problems.
...
Secondly, they state that debris would likely reenter after one orbit.
Is
this accurate. I would have though debris capable of hitting the ISS
would
orbit significantly more than once.

In hypervelocity impacts, where thing A hits thing B at several km/s,
you tend to get two clouds of debris that move along the original paths
of A and B. If both A and B are in sub-orbital trajectories before the
collision (like an ICBM and probably the interceptor) then so will the
debris clouds.

Sure but that is not what the article is talking about. Both A and B will
not be in sub-orbital trajectories. The weapon will be based in space at
orbital velocity. Given that impact is likely to be above the atmosphere,
wouldnt that tend to make some of the debris assume a orbital or close to
orbital speed. As such, would not a large amount of debris follow the
original orbital track but with a perigree slightly closer to the earth than
the original launch platform and an apogee slightly higher than the launch
platform.

Right, I misread the article.

If you have a space platform firing interceptor missiles at ICBMs,
then, if you fire the interceptors in a prograde direction (adding to
the platform's orbital velocity) then the interceptor is in an orbit
that stays above the atmosphere, and so will its debris cloud if it
hits something. However, if you fire your interceptor retrograde, or
Earthward or zenithward with any significant velocity, then the
interceptor and subsequent debris will re-enter. Other directions, it
depends.

For testing the system, you can choose the shootdown direction. Of
course, some might argue that a full comprehensive testing program
would be need to cover all directions. But the US ABM program has
tried to keep testing as minimal as possible.

Testing can find problems. Problems can lead to delays or even
cancelling of development, deployment and, more importantly, payment.
That's why we have a couple of brand new, expensive, ABM interceptors
in silos in Alaska, but no testing for the past couple of years.
http://www.aps.org/WN/WN04/wn091704.cfm

--
David M. Palmer (formerly @clark.net, @ematic.com)

"David M. Palmer" wrote in message
...


Testing can find problems. Problems can lead to delays or even
cancelling of development, deployment and, more importantly, payment.
That's why we have a couple of brand new, expensive, ABM interceptors
in silos in Alaska, but no testing for the past couple of years.
http://www.aps.org/WN/WN04/wn091704.cfm

--
Interesting. One would hope that Nasa has enough swing to ensure that no
significant damage can be done to the orbital environment. But then again,
NASA versus the Military isnt really a fair battle

Christian Ramos ) wrote:

: "David M. Palmer" wrote in message
: ...

:
: Testing can find problems. Problems can lead to delays or even
: cancelling of development, deployment and, more importantly, payment.
: That's why we have a couple of brand new, expensive, ABM interceptors
: in silos in Alaska, but no testing for the past couple of years.
: http://www.aps.org/WN/WN04/wn091704.cfm
:
: --
: Interesting. One would hope that Nasa has enough swing to ensure that no
: significant damage can be done to the orbital environment. But then again,
: NASA versus the Military isnt really a fair battle

Yeah, the military gets 26 times what NASA gets from the US Govt. budget.
I wonder what the citizen donation ratio is?

Eric