Posted to sci.astro:

*******************************************
Newsgroups: sci.astro, sci.physics, sci.space.policy, sci.astro.amateur, us.military.army
From: Robert Clark <rgregorycl...@yahoo.com>
Date: 2 May 2007 15:50:17 -0700
Local: Wed, May 2 2007 6:50 pm
Subject: Re: Orbital surveillance satellites now exceed 1 inch resolution.

On May 1, 5:28 pm, Jochem Huhmann <j...@gmx.net> wrote:
> Robert Clark <rgregorycl...@yahoo.com> writes:
> > This passage describes it as having a large surface area for the given
> > weight. But note this means it also has a very low weight for its
> > given surface area.
> > A key feature of the James Webb Space Telescope is also its low weight
> > for the size of its mirror. This is because of its beryllium mirror
> > which allows very thin mirror blanks.
> > So this low weight of the Misty satellites is consistent with
> > segmented beryllium mirrors.

> Or, if it has a very large surface for its mass it just may have a
> large, lightweight, deployable structure... could be a radar spysat.
> ...

Definitive proof one way or the other would be given by telescope
observations. This page shows images by a 1 meter scope of Mir and ISS
at around 400 km altitude:

Gallery - Artificial Satellites.
http://www.tsm.toyama.toyama.jp/curators/aroom/satellite/index.htm

These space stations are around 30 to 40 meters wide at their widest
dimensions. So at 2000 km altitude and 1/5th the size, the object in
question would appear 1/25th the size of the stations in these images.
You could probably resolve its shape. Of course a 2 meter scope could
do better.
The largest amateur scopes seem to be of size 1 meter. Two meter and
larger scopes are available at universities.
Some meter sized scopes available to amateurs:

The Searchers.
The World's Largest Amatuer Telescope Draws Scientists to the
Wilderness.
http://www.titanmag.com/2004/searchers/index.htm

Dan Bakken & Hercules.
http://www.runway.net/pilots/dan/welcome.html

The observatory of Puimichel.
http://www.groupeastronomiespa.be/pui.htm

And the Faulkes telescope project might be especially useful. It
provides access to two meter scopes for educational purposes:

Faulkes Telescope Web Site.
"The Faulkes Telescope Project is the education arm of Las Cumbres
Observatory Global Telescope Network (LCOGTN).
"Our aim is to provide free access to robotic telescopes and a fully
supported education programme to encourage teachers and students to
engage in research-based science education.
"Access to our resources and those of our partners is provided at no
charge to teachers and students."
http://faulkes-telescope.com/information/about_us

Bob Clark
*******************************************

However, I've been informed on the Bautforum.com list in a thread under
this same title that I didn't take into account the effects of
atmospheric distortion. This limits resolution to .5 arcseconds
regardless of the size of the scope if you don't have adaptive optics.
This means at 250 km altitude, your resolution could be at best 23
inches without adaptive optics. So at 2500 km, your resolution might
be only about 6 meters.
Then my hypothesized 6.5 meter mirror might not be resolvable without
adaptive optics if the satellite was above 2000 km.
(The object tracked by amateurs that had a high surface area to weight
ratio was orbitting at above 2000 km altitude.)

In any case the actual purpose of this discussion was to promote the
producing of satellites with large multisegmented mirrors for planetary imaging purposes. Publicly revealing secret military satellites with this capability probably wouldn't be the best way of achieving that.
It is already pretty certain anyway that we have the technical
capability for doing this in visible wavelengths. The question is of
the cost. I was arguing that commercial satellite interests investing
in this would lower the cost for the production of satellites for
planetary imaging. There are privacy concerns, but there would be some
beneficial societal effects as well.
We can imagine that such satellites are orbited in sufficient number to provide world-wide round-the-clock coverage to be able to distinguish faces and license plates. You could use "light intensification" or infrared viewing devices for imaging at night. This though raises the spectre of "Big Brother" in outer space.
However, an advantage would be the great reduction in crime this
would produce. For any crime committed you could trace back in the
images the houses that the perpetrators orginated from.
This would be preventive in the sense the perpetrators would know
they would soon be tracked and identified. However, in the case of
terrorists in many cases they wouldn't care that they would be caught
or identified. But this could be preventive if certain suspected
terrorists could be put under round-the-clock surveillance. Then
certain illegal activities or purchases could be identified beforehand
to stop the terrorist acts before they take place. You could also do
spectroscopy from space so that production and/or transport of
explosives would automatically set up a red flag to alert to the
possibility of terrorism.
The privacy concerns would be magnified even further by ongoing
research on imaging methods that can see through clothing and even
walls, if these methods were placed on satellites:

First Image from Revolutionary T-ray Camera; Sees through Fog,
Clothing and into Deep Space.
By Robert Roy Britt
Senior Science Writer
posted: 01:30 pm ET
11 February 2003
http://www.space.com/businesstechnology/technology/t-ray_camera_020613.html

Tuesday, February 20, 2007
T-Rays Advance Toward Airport Screening.
A new laser design helps create usable terahertz radiation, which
penetrates common materials but doesn't harm tissue.
By Neil Savage
"Zhang founded a company, Zomega Terahertz that makes a laptop-size T-
ray detector that can be attached to a flying drone for remote
detection of chemical and biological substances. While the trillionths
of a watt produced by the infrared laser in the device is fine for
spectroscopic analysis of air samples, it's not adequate for imaging,
and the laser technology is unlikely to improve enough to be used in
airport security, Zhang says. He believes that quantum cascade lasers
are the future of T-ray detection systems: "They will be the final
winner in the market."
http://www.technologyreview.com/Infotech/18203/page1/

The question: would you favor the use of such satellites if it would
virtually eliminate crime and terrorism?
How about if the imaging was only available to government agencies
and it required a court order to initiate preventive prior
surveillance or the tracing back in video of an individuals movements
in time?

Bob Clark

c.f.:

Space Sciences
Orbital surveillance satellites now exceed 1 inch resolution.
Posted by Robert Clark on 4/23/2007 3:00:00 AM
http://habitablezone.com/space/messages/466356.html