FW: [Sis-csi] Dust impact?

[Fred Slane]

Second try
 
Fred
 
Frederick A. Slane
President
Space Infrastructure, Inc.
1219 North 31st Street
Colorado Springs, CO 80904
(719) 634-3194
freds at spacestandards.com
www.spacestandards.com
 
-----Original Message-----
From: Fred Slane [mailto:fas1 at adelphia.net] 
Sent: Thursday, October 27, 2005 11:33 PM
To: 'sis-csi at mailman.ccsds.org'
Cc: gary.rod at att.net
Subject: RE: [Sis-csi] Dust impact?
 
Larry Taylor has imaged lunar dust samples at the sub-5 micron range.
There is every reason to expect dust populations down to the molecular
scale (suggesting a smooth transition in population to small charged
particles - "dusty plasmas").  My analysis of Lunar Laser Ranger data
(1969 -1990, red light) shows significant attenuation as the
retroreflector passes through the terminator. (Google "Lunar Dust
Levitation")  So dust movement is driven by natural phenomena (space
weather) on a periodic cycle.  Certainly astronauts noticed and
commented on the problem.  Jack Schmidt (an Apollo astronaut and
geologist who did go to the Moon) is one of the DUST team members.  In
short: Yes, there is lots of data.  And communications "bounce" is a
potential problem (physics being physics).
 
Cheers,
Fred
 
Frederick A. Slane
President
Space Infrastructure, Inc.
1219 North 31st Street
Colorado Springs, CO 80904
(719) 634-3194
freds at spacestandards.com
www.spacestandards.com
 
-----Original Message-----
From: Scott, Keith L. [mailto:kscott at mitre.org] 
Sent: Thursday, October 27, 2005 7:48 AM
To: Fred Slane; sis-csi at mailman.ccsds.org
Subject: RE: [Sis-csi] Dust impact?
 
Hmm.  Any notion of what such dust would do to a Ka-band or X-band
signal?  If it changed the permittivity of the atmosphere significantly
I guess it could refract or attenuate a signal.  Presumably the effects
of 'free' (didn't want to say airborne) dust on the moon would be
relatively short-lived unless it happened to coat an antenna.  Mars has
dust storms and those pesky dust devils.  ANy pointers to data?
 
        --keith
 

  _____  

From: sis-csi-bounces at mailman.ccsds.org
[mailto:sis-csi-bounces at mailman.ccsds.org] On Behalf Of Fred Slane
Sent: Wednesday, October 26, 2005 9:36 AM
To: sis-csi at mailman.ccsds.org
Subject: RE: [Sis-csi] Dust impact?
Mike raises the point of lunar dust.  Our investigations under Project
DUST indicate the "dusty plasma" on the Moon will be a significant
contributor to work on and near there. There are also data to suggest
similar, but not the same, effects on Mars.  Our investigation started
looking at simple geophysical and geochemical properties and
implications of dust.  We have assembled a good information base which
needs to find its way to others (such as the space communications
crowd).
 
We have initiated standards development in the ISO TC20/SC14 Space
Environments Working Group on dust, dust simulants and extensions of
space environment models to local operational scales on the Moon and at
Mars.
 
Cheers,
Fred
 
Frederick A. Slane
President
Space Infrastructure, Inc.
1219 North 31st Street
Colorado Springs, CO 80904
(719) 634-3194
freds at spacestandards.com
www.spacestandards.com
 
-----Original Message-----
From: sis-csi-bounces at mailman.ccsds.org
[mailto:sis-csi-bounces at mailman.ccsds.org] On Behalf Of Kearney, Mike
Sent: Wednesday, October 19, 2005 4:53 PM
To: sis-csi at mailman.ccsds.org
Subject: RE: [Sis-csi] Telecon tomorrow
 
This is the drawing that Keith was talking about.  
 
A few comments:
 
This gives one the impression that RTT is the only defining boundary on
Cislunar space.  There are other characteristics for lunar programs
besides RTT, so RTT should not be the only defining parameter. Others
could be lunar dust, mountain/crater rim blockage, a certain pattern of
AOS/LOS, Need to explain in the text in the scope section that for this
particular parameter, RTT, a 10 sec. RTT was chosen as the limit that
our solutions work for, and Cislunar solutions should work in other
environments (Mars Local) for mission spaces within 10 sec. RTT.
 
Another open question. Should the Mars Cislunar range go out to Sun-Mars
L2?  For a comm satellite that covers the Martian far side?  I assume
that since Mars is lower mass than earth, SML2 is closer to Mars than
SEL2.  But not being a celestial mechanic, I'm not sure.  If we feel
lucky, we could put SML2 inside the Mars blue circle, and if we're
wrong, or irrelevant, I'm sure someone would tell us.  
 
 
   -=- Mike
 
Mike Kearney
NASA MSFC EO-01
256-544-2029

  _____  

From: sis-csi-bounces at mailman.ccsds.org
[mailto:sis-csi-bounces at mailman.ccsds.org] On Behalf Of Scott, Keith L.
Sent: Wednesday, October 19, 2005 4:41 PM
To: sis-csi at mailman.ccsds.org
Subject: [Sis-csi] Telecon tomorrow
 
Let's have a short telecon tomorrow.  I'd like to get a feel for any
feedback we've gotten and talk about Mike's new scope picture and how to
start wrapping this up.
 
703.983.1550 x 55555
 
        --keith
 
 
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