From: ch.steyaert@abbs.hanse.de (Chris Steyaert)
Newsgroups: sci.astro
Subject: UNAMSAT-1: meteor astronomy from space
Reply-To: ch.steyaert@abbs.hanse.de
Date: 27 Sep 92 21:56:00 MET
Distribution: sci
Organization: ABBS AstroMail, D-W 2121 Dahlenburg / Germany
X-Version: ZerUU V6.45c

The beginning of the end of Earth-based meteor observations with its

    - global coverage
    - weather independency
    - high precision orbital data
    - reliable activity assessment

?

"UNAMSAT-1 (UNAM = Autonomous University of Mexico) is another of the 
MICROSAT series and has much in common with AO-16/DO-17/WO-18/LO-19. 
The innovative new addition in UNAMSAT-1 is the brand new on-board
experiment in the 5th "TSFR" ("This Space For Rent") module:

UNAMSAT-1 primary mission is to act as meteor sounder.  It will contain a
40.097 MHz transmitter with 60 watts output during pulses from which can
be varied from 1 to 10 msec in duration and with a pulse repetition rate
of 1 to 10 seconds, as controlled by a 68HC05 CPU.  The meteor echoes will
be detected on a receiver at the same frequency designed to detect the
returned echo and measure its doppler shift.  The use of the meteor sounder
is to obtain research data on the full-sky spatial and velocity distribution
of meteors, with the focus on a search for high-velocity meteors originating
outside our solar system.

The 41 MHz frequency for this transmitter is in accordance with the ITU
frequency allocations table for scientific research and both the 41 MHz and
amateur frequencies have been licensed by Mexican authorities. 

The meteor receiver is a SSB "zero-IF" design and the return echoes are
digitized and stored in the normal V40 MICROSAT computer's RAM.  After each
pulse, the spectrum of the received signal will be determined using the
onboard V40 as a DSP Fourier Transform spectrum analyzer.  If a meteor echo 
is detected, the echo will be saved for later transmission as a special
telemetry frame. 

The 1-10 second repetition rate for the meteor transmitter will be adjusted
depending on the state of charge of the batteries and other spacecraft power
requirements, and also on the time domain requirements of the echoes. 

When UNAMSAT-1 is not involved in meteor research, it can be turned into a
standard PACSAT message store-and-forward satellite.

XE1TU has been responsible for technical development of UNAMSAT-1 along
with the team of hams and students at the University. Scientific direction
for the project has been provided by UNAM Professor of Astronomy Arcadio
Poveda. AMSAT-NA provided technical details of its MICROSAT satellites to
UNAM.

The UNAMSAT-1 launch will also be the beginning of a new era.  Along with 
a larger meterological satellite, it will be launched by the Russian Space
Agency and by the Russian Academy of Sciences on a decommissioned SS-18 
ICBM into an orbit about 1000 km high.  At this time the launch is scheduled
for the first week of December, 1992."

[Source: AMSAT News Service (ANS) via Maurice De Meyere, ON4NU].

--

    Chris Steyaert
    Dr. Vandeperrestr. 83
    B 2440 Geel
    Belgium
    tel (32)14582075   fax (32)14221373
    E-mail:Chris.Steyaert@f852.n292.z2.fidonet.org
 
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