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[jamsat-news:691] * SpaceNews 17-Nov-97 *
SB NEWS @ AMSAT $SPC1117
* SpaceNews 17-Nov-97 *
BID: $SPC1117
=========
SpaceNews
=========
MONDAY NOVEMBER 17, 1997
SpaceNews originates at KD2BD in Wall Township, New Jersey, USA. It
is published every week and is made available for non-commercial use.
* RS-17 / SPUTNIK-40 NEWS *
===========================
RS-17/Sputnik-40 continues to be heard well throughout the world, even
with modest receiving equipment. The one-third scale Sputnik replica is
currently transmitting on 145.820 MHz with about 200 mW of power.
Francois, VE2FCA in grid locator FN45AJ, received Sputnik-40 on the
following occasions:
05-Nov-1997 13:57, 14:39, 15:19 UTC
06-Nov-1997 12:54 UTC
07-Nov-1997 08:40, 13:27, 16:42 UTC
The signal was reported quite weak but was received with clear audio.
Mike, VE2TRV in grid locator FN35CP, received the satellite's signal on
11-Nov-1997 (1255 UTC) and 12-Nov-1997 (1331 UTC), the latter occasion
with a very strong signal on a near-overhead pass. Rig used was a Yaesu
FT-208R handheld with a 1/4-wave telescoping whip.
The following Keplerian element set currently provides accurate tracking
and orbital predictions of RS-17/Sputnik-40:
RS-17
1 24958U 97058C 97317.37650187 .00036370 00000-0 43179-3 0 156
2 24958 51.6590 55.8829 0006516 312.1806 47.8321 15.60798196 1516
* SAFEX-II NEWS *
=================
The SAFEX-II project on the Russian Mir Space Station is back on the air.
Over the past few months, the Mir crews have been able to restore most of
the power generating systems which were damaged in the June 25 collision.
There is now enough extra power available to turn on the SAFEX-II 70-cm
repeater. The repeater supports three different communications modes
including voice QSO, FM repeater, and 9600 baud packet. Each mode has
been assigned a specific frequency pair:
Downlink Uplink PL
----------------------------------------------------------------------
FM voice QSO, used to talk to the Mir Crew : 437.925 435.725 151.4
FM repeater, use just like any FM repeater : 437.950 435.750 141.3
FM 9600 baud packet : 437.975 435.775 None
Only one mode will be active at a time.
The Mir space station and the SAFEX-II project are traveling around the
Earth at over 17,500 mph (28,000 kph). This great speed will make radio
signals appear to shift in frequency as a result of the Doppler effect.
The total Doppler shift for a transmitter on 437 MHz will be approximately
20 kHz. There will be a plus 10 kHz shift during the first 5 minutes of
the pass, followed by a negative 10 kHz shift during the last 5 minutes
of the pass. The Doppler shift will cause the Mir transmit frequency
(437.950 MHz) to look like it is approximately 10 kHz higher in frequency
when Mir is approaching your location. Because of the large Doppler shift
and the present antenna orientation, a large amount of ERP (500-1200 watts)
is required to access the repeater reliably. The average transmitter power
output from the repeater is 1.5 watts. This satellite cannot be considered
an Easy-Sat.
To access the FM repeater, groundstations need to compensate for the Doppler
effects during EACH transmission. The uplink frequency error into the
repeater must be less than 2 kHz on each transmission. The greater the
frequency error, the harder it will be for the repeater to receive and
decode the uplink subaudiable access tone. The access tone control is
used to help reduce interference from getting into the repeater.
Groundstations capable of only 5 kHz frequency steps may have difficulty
accessing the SAFEX-II repeater. MIREX suggests that such stations "tail
end" off someone else's transmission to catch some of the squelch tail
delay.
The following consecutive odd split frequencies may be programmed into
a groundstation transceiver to allow access to the SAFEX-II repeater on
Mir. A similar channel plan can be use for the voice QSO mode and the
9600 bps packet radio mode.
Repeater channel configurations for 2.0 kHz channel step transceivers
Channel Downlink Uplink Doppler Offset
1 437.940 MHz 435.760 MHz +10 kHz 2.180 kHz
2 437.942 MHz 435.758 MHz + 8 kHz 2.184 kHz
3 437.944 MHz 435.756 MHz + 6 kHz 2.188 kHz
4 437.946 MHz 435.754 MHz + 4 kHz 2.192 kHz
5 437.948 MHz 435.752 MHz + 2 kHz 2.196 kHz
6 437.950 MHz 435.750 MHz 0 kHz 2.200 kHz
7 437.952 MHz 435.748 MHz - 2 kHz 2.204 kHz
8 437.954 MHz 435.746 MHz - 4 kHz 2.208 kHz
9 437.956 MHz 435.744 MHz - 6 kHz 2.212 kHz
10 437.958 MHz 435.742 MHz - 8 kHz 2.216 kHz
11 437.960 MHz 435.740 MHz -10 kHz 2.220 kHz
When Mir is approaching your QTH, use channels 1 through 5. Then when
Mir is directly overhead, use channel #6. When Mir passes your QTH and
begins to recede, use channel 7 through 11. For best results you should
use a computer tracking program which displays the current Doppler shift
for 437.950 MHz. A program such as InstaTrack or SatTrack will display
the Doppler shift in real-time. This will assist you in determining when
it is the best time to change channels. If your groundstation transceiver
is equipped with an FM center tuning meter, you can use this meter to
assist in determining when it is time to change channels.
The 9600 baud packet mode of this repeater has not yet been used. The
information received from the crews indicates they have not been able to
get the built-in 9600 baud TNC to respond to the terminal programs on Mir.
One possible scenario is that the TNC may be in "Host Mode", which requires
special software that is not available on Mir. Whatever the problem, do
not expect SAFEX-II 9600 baud packet operations to be available this year.
[Info via Miles Mann, WF1F]
* STS-87 ORBITAL DATA *
=======================
What follows is the nominal State Vector and Keplerian Elements for STS-87.
The vector data comes from NASA; the Keplerian Elements were computed from
the vector.
This file may be read by VEC2TLE version 9648 to update your
Keplerian Elements text file.
Vector format = 10117
Satellite Name: STS-87
Catalog Number: 99987
Epoch MET: 0.03001030100
0/00:43:12.890 MET
EFG E: 9732372.58899999 ft
F: 17189716.7899999 ft
G: -9361179.8719999 ft
Edot: -21474.160303456 ft/s
Fdot: 9266.87806510699 ft/s
Gdot: -5300.8229414059 ft/s
ndot/2 (drag): 0.00040121794 rev/day^2
nddt/6: 6.72842E-09 rev/day^3
Bstar: 8.95827E-05 1/Earth Radii
Elset #: 1
Rev @ Epoch: 1.67780888922
Launch scheduled: 19-NOV-97 / 19:46 UTC
Note that "99987" is a temporary Catalog Number for STS-87. Once STS-87
is launched, a permanent Catalog Number and International Designator will
be assigned.
The following Keplerian elements were computed by VEC2TLE from this vector,
and the scheduled launch time using a 1.0 drag multiplier:
STS-87
1 99987U 97323.85362141 .00040122 67284-8 89583-4 0 11
2 99987 28.4670 185.6850 0002865 329.1052 274.9205 15.96550274 11
Satellite: STS-87
Catalog number: 99987
Epoch time: 97323.85362141
Element set: 1
Inclination: 28.4670 deg
RA of node: 185.6850 deg
Eccentricity: 0.0002865
Arg of perigee: 329.1052 deg
Mean anomaly: 274.9205 deg
Mean motion: 15.96550274 rev/day
Decay rate: 4.01218e-04 rev/day^2
Epoch rev: 1
Checksum: 313
VEC2TLE may be downloaded from:
http://www.amsat.org/amsat/sarex/orbit.html
The STS-87 Nominal Mission Orbit Profile and State Vectors have been
uploaded to the AMSAT Web site. They are available for download at:
http://www.amsat.org/amsat/sarex/vectors.html
As always, actual updates to the Shuttle's orbit will be posted on the
Shuttle Orbital Data page at:
http://www.amsat.org/amsat/sarex/orbit.html
[Info via Ken Ernandes, N2WWD]
* SpaceNews 10th ANNIVERSARY *
==============================
It's official. SpaceNews is now in its tenth year! Upcoming issues will
provide a brief history of the publication, and outline some of its major
accomplishments. Stay tuned. :-)
* THANKS! *
===========
Thanks to all who sent messages of appreciation to SpaceNews, especially:
EB3FNW KF6BUY F6HCC LU8EBH
* FEEDBACK/INPUT WELCOMED *
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/EX
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