From: dave@ips.oz.au (Dave Horsfall)
Subject: * SpaceNews 24-Aug-92 *
Organization: IPS Radio and Space Services.  Sydney, Australia.
Distribution: aus
Date: Mon, 24 Aug 1992 03:47:40 GMT

Bulletin ID: $SPC0824


                              =========
                              SpaceNews
                              =========


                        MONDAY AUGUST 24, 1992


SpaceNews originates at KD2BD in Wall Township, New Jersey, USA.  It
is published every week and is made available for unlimited distribution.



* A LOOK AHEAD *
================
The following is a summary from discussions held at the recent AMSAT-UK
Colloquium, and comes to us from Richard, G3RWL:

Arsene:
Its all finished, in its box, waiting to fly.  To recap on last year's
information, it will be 3-axis stabilized with Sun and Earth sensors, attitude
control is by gas jets after ground command (about twice per year).  VHF/UHF
aerials are monopoles, with dipoles for 2.4 GHz.  Digipeater uplinks
435.050/100/150 MHz, downlink 145.975 MHz 2W and 15W.  Transponder uplink
(16 KHz wide) 435.110 MHz, downlink 2446.540 MHz (0.8W, estimate 2.5m dish
required).  Expect doppler shift (2m/70cm) in final orbit to be about 3 Hz per
minute.  Orbit period 17H30 with perigee 20,000 and apogee 36,000 km.  This
should produce a slow drift from west to east with 12 hours/day average access.
Launch on Ariane V58 with the Astra 1C satellite in less than one year.

Phase-3D:
Launch is confirmed on the second Ariane-5 test flight but may move to the
first; still with the "cluster" spacecraft.  Eventual orbit is unchanged
(apogee 47714, perigee 4000 km, inclination 63.4).  Orbital manoeuvers will be:
1) raise perigee at an early apogee.  2) burn at perigee to raise apogee to
50,000 km.  3) burn at apogee for inclination change.  4) synchronize orbit
after final drift.  Manoeuvres 1-3 will be done by the main (400N) motor
burning MMH/N2O4; subsequent ones, and station-keeping, will be done with
electric propulsion (100N, isp about 500sec) burning NH3 (ammonia).  Solar
panels will be deployed after the third burn then they'll de-spin and wait
about four weeks while the apogee drifts north before the fourth burn.  Final
stable orbit (period = 16 hours) is not expected to be achieved for about one
year but the satellite will be available to users much earlier than this.

Earlier plans had suggested the use of pattern-agile antennas, this will not
now occur, instead the spacecraft will employ 3-axis stabilization by means of
momentum wheels even though this will create thermal stabilization problems.
The shape is triangular with the points cut off.  Non-radio payloads are SCOPE,
a Japanese camera system, and an atomic clock.  Regrettably, due to lack of
resources, the hoped-for Mars probe will NOT be included.

SedSat:
This equipment, made in Alabama, will replace the weight on the end of a space
tether experiment flying on NASA's SEDS-2 mission (on a Delta rocket) between
the end of 1993 and mid-1994. Planned life is five years.  Orbit details -
inclination 39 deg, altitude 680/792 km; it will be deployed upwards 46 km
from the Delta's upper stage. Equipment carried will be mode A and mode J;
digital images (initially of the tether), as well as telemetry will be
transmitted on 70cm. Initial plans speak of a mode A transponder with a 300
bps BBS at the LF end and a digitalker at the HF end of the downlink passband;
also FM uplinks will be downlinked as SSB (!).  At the end of the tether
experiment (i.e. about six months) SedSat will be released from the tether to
fly autonomously for the rest of its lifetime.

TechSat:
This is a MicroSat-class package being constructed in Israel. It carries the
following experiments: packet store and forwarding; GPS receiver; radiation
measurements; DSP; and is intended to be compatible with existing digital
communications software.  It will have three uplinks (on 2m and 23cm) and a
70cm downlink.  The power budget is designed to work with omnidirectional
ground-station antennas.  It will be 3-axis stabilised. Launch is planned on
Ariane into a sun-synchronous 700 km orbit.

ITAmsat:
As reported last year, this unit is mechanically identical to a MicroSat and
will be compatible with existing digital communications software.  Amsat-I
have already produced a functional prototype; all of the flight hardware will
be made in Italy (except for the solar panels). Launch will be on the Ariane
SPOT-3 mission (more on this later).  It will support 1200 (Fuji) and 9600 bps
(UO-22) digital modulation. Uplinks are on 145.875/900/925/950 MHz and the
two downlinks will be on 435.760/810 MHz.

KitSat-B:
Similar to OSCAR-23, but hopefully will include a GPS receiver.  Launch
on SPOT-3 mission (below).

HutSat:
This is a three-year Finnish project to test the technology and produce an
engineering model leading to a later Ariane launch (in 1997/98).  The aims are
to use new GaAs technology and to give occupancy of presently unused
frequencies.  It will carry a digital transponder, BBS and DSP experiments and
use 435/1260/2400 MHz links (no 2m).  (The OH-built 10 GHz transmitter for P3D
has already been delivered to Germany.)

Spot-3 Mission:
This flight is currently expected in mid- to late-1993.  It carries the
replacement for Spot-2 so if Spot-2 continues to function well the flight is
likely to be delayed.  Conversely, if Spot-2 meets problems the launch will be
earlier.  We should expect a similar orbit to the current MicroSats.  As well
as Spot-3 it will have an ASAP carrying KitSat-B, ITAmsat, and two Portuguese
amateur radio satellites (from a University but no other information available
because it has not yet been finalized).


* WORLD SPACE CONFERENCE NEWS *
===============================
In addition to Hans van de Groenendaal, ZS6AKV, delivering a paper
at the World Space Congress 1992 in Washington, DC, Alex Zaitzev,
RW3DZ also plans to present a report entitled "The School e-mail
system via PACSAT satellites for educational purposes" on 03-Sep-92.

[Info via Alex, RW3DZ]


* NEXT WEEK *
=============
Coming up next week will be a detailed report on the next Radio Sputnik
satellite: RS-15.  Stay tuned!


* FEEDBACK/INPUT WELCOMED *
===========================
Mail to SpaceNews should be directed to the editor (John, KD2BD) via any
of the following paths:

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MAIL     : John A. Magliacane, KD2BD
           Department of Electronics Technology
           Advanced Technology Center
           Brookdale Community College
           Lincroft, New Jersey  07738
           U.S.A.


    <<=- SpaceNews: The first amateur newsletter to be read in space! -=>>

-- 
Dave Horsfall (VK2KFU)         VK2KFU @ VK2RWI.NSW.AUS.OC
dave@ips.OZ.AU                  ...munnari!ips.OZ.AU!dave
Newsgroups: aus.radio.amsat