[amsat-bb] Re: NMARS

[David Goncalves]

 Amatuer Satellite Fans,

Re-entry for RAFT will occur not too long from now; it was launched as the
same time as MARSCOM (RAFT's mass will keep it in orbit longer). While a
couple people have tried to turn on the RADAR transponder over the Southern
U.S (thanks to CAPE team and others)., we have yet to hear a successful
downlink of the RADAR reciever audio as it passes over the fence. Please
read the attachment below; are there any hams who can help? I, and the XP217
team, who built the RADAR transponder, really want to see this device work -
we know it should, we know the oscillator is working (thanks to our European
friends), but we don't yet know if the device can downlink the RADAR audio
tone.

Can nobody help? Whether it is a single person with all the equipment, or a
team of people working together  over the phone to manage all the steps
required, if there are hams in the Sothern U.S., technically able to command
the satellite, turn on the transponder, and listen and record the FM
downlink, we are interested in hearing from them. Contact Bob Bruninga, or
myself.


David Goncalves
W1EUJ

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The RAFT Radar Transponder has been detected.  See plot:
http://www.ew.usna.edu/~bruninga/craft/XP217-PE1ITR4feb07.JPG

Although the 4 milliwatt RAFT Radar Fence oscillator was
designed to be heard by the collosal 2 mile long 30 dB gain
receive antenna of the Radar Fence across the southern USA,
PE1ITR was able to detect the oscillator on his own ground
station.

We are still welcoming GOOD OSCAR class AMSAT stations near the
RADAR fence across the southern USA (Arizona through Texas to
Georgia) who have good 2 meter beams, to command on the RAFT
Radar fence transponder so that we can make our first Radar
Fence detection.  RAFT requires a good 2m beam station to
operate it.

The primary objective is for RAFT's radar xponder to HEAR the
radar fence as it flies through it.  Since this is not
detectible here at USNA due to our latitude, we are dependent on
volunteer ground stations in the southern USA to activate the
RAFT transponder at precisely the correct time to make this
detection.  There is only one good pass per station in the
evening hours and so it is slow going.

But the detection above, gives great confidence in the primary
objective..

For more on RAFT's radar Fence Transponder which is a model for
future small satellites to be able to detect their own passage
through the fence, see the main RAFT web page about half way
down the page:
http://www.ew.usna.edu/~bruninga/raft.html



-- 
David Goncalves