[Fwd: Re: [LASER] P3D Laser experiment]

[Joseph B. Fitzgerald]

The filter I referenced is a 40 nm wide unit I got from Coherent.  They
claim 80% transmission at 835 nm.  

I don't have any better info than the article on G0MRF's web site, except
for a version of the article with a block diagram of the laser system at
http://members.verizon.net/~km1p/IR_LASER_P3D.pdf  I'll send a couple of
e-mails and see if I can scare up any better info.  

The biggest problem I see in this project is pointing - on both ends.  I'm
told the sensor system on board the spacecraft is only good to 8 bits or
1.4 degrees.  It remains to be seen how accurately the reaction wheels can
be controlled.  So there is another 3-6 dB hit to the link.  Pointing the
telescope on our end is problematic also. I believe the orbital prediction
programs are only good to around .1 degree or so. 

As far as permanent damage to the optics, it's really not all that bad,
and there is some evidence that whatever got on the camera lens is
evaporating. See http://www.amsat.org/amsat/features/yace00292/.  Not much
has been done with the cameras aboard as the spacecraft is still spin
stabilized and as a result the pictures are pretty lousy.  

-Joe KM1P