Med tanke p kommande Mars sond som Amsat DL hller p att frdigstlla s kan det hr vara av intresse.
During the period August 26-29 2003, NASA s Jet Propulsion Laboratory (JPL)in cooperation with the Stanford Research Institute (SRI) will be conducting a test of the Mars Relay transmitter aboard the Mars Global Surveyor (MGS)
spacecraft currently in orbit around Mars.
The test involves the spacecraft transmitting a 1 watt 437.1 MHz CW carrier for reception by the 46 meter dish at SRI.
Amateurs with 70cm EME class stations using DSP techniques may be able to detect this signal also. Andrew Bachler, N9AB, was able to detect a similar transmitter aboard Mars Odyssey while it was on its way to Mars in June of 2001.
This test will be somewhat more challenging as MGS
will be 3 times further away.
Dr. John Callas of JPL explains some of the difficulties involved: MGS will be entering and exiting occultati(blockage by Mars with respect to Earth)with each 118-minute orbit.
Furthermore, its UHF antenna (with about 0 dBi of gain, EIRP~30 dBm) will only be viewable from Earth for a few minutes (5 to 15 minutes) just before ingress and just after egress as it orbits.
Full details of the test timeline are available at
http://members.verizon.net/~km1p/ .
Joe Fitzgerald KM1P
Klla: www