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Re: Mir Status July 12,1999, PMS move





How to work the NASA Space Shuttle, on Packet/Voice
by Miles Mann WF1F MAREX-NA

This Packet bulletin originates at WF1F in Chelmsford, Mass, USA.  It is made
available
for unlimited distribution.

Working the NASA Space Shuttle on FM packet or voice is easier than you may
think.
I have been able to connect to the NASA Space Shuttle with a very modest 2-meter

station (on a good pass).  But you must be very careful to prevent QRM.
There is an official NASA web page for SAREX.  The frequencies listed below may
change, however the theory can be applied to what ever new frequencies are
chosen.

http://www.gsfc.nasa.gov/sarex/sarex_news.html
or
http://garc.gsfc.nasa.gov/~kc6rol/sts93.html

The NASA Space Shuttle is operating FM Packet/Voice on the Amateur Radio 2-Meter
 band.   The frequency pairs for this mission will be:

Usage               Down Link Up-link         Frequency difference
Packet              145.800   144.490         (-1.310 odd split)
European voice 145.800   144.490         (-1.310 odd split)
Voice               145.800   144.470         (-1.330 odd split)
Voice               145.800   144.450         (-1.350 odd split)
School Contacts     145.800   Unlisted

This year SAREX is going to try a public down link for school contacts.  Several

schools have made prearranged schedules with the Shuttle.  Each school will have
 a specifically assigned Uplink channel for that school.  The uplink frequencies
 are not published for many reasons.  I proposed the School-Public down link
idea to SAREX-WG in 1995 and again at the first ARISS meeting in 1996.  At the
 time MAREX-NA was assisting SAREX-WG with the school schedules for the American
 crew members living on Mir.  We wanted the schools schedules with Jerry
Linenger
 and others on Mir to be open to the public so that many could hear at least one
 side the conversation from Mir during Jerry's schools.  Unfortunately the idea
 was rejected because of fears of QRM.  Fortunately my proposal has resurfaced
 and we hope for their success.  You to can help make the Public down link a
 success by following a few simple rules.
1. Never transmit any signal on the Shuttle down link frequency.
2. Encourage schools and other groups to tune in an monitor the public down
 link frequency.
3. If you just happen to discover a school uplink channel by accident, do
 not publish this information.

The Down link frequency is the channel you listen on for the shuttle, and
 the up-link frequency is the channel you should transmit on for the Shuttle
 to hear you.   The NASA Space Shuttle does not monitor the channel 145.800
 (primary down-link channel).  If you call the Space Shuttle on down-link
 channel they will not hear you!

The crew on the NASA Space Shuttle will switch between the three different
 channels depending on what part of the world they are over.  In the USA,
 the 145.800/144.490 is the primary pair.  Unfortunately, Terrestrial
packet BBS stations are usually on this same range of channels in the USA,
 which usually make it very difficult to work the Shuttle if you live near
 an active Packet BBS or APRS station.  (One of the USA Packet BBS simplex
 channel is on 145.790 Packet and APRS there is no guard band in the USA to
 reduce QRM to the satellite band) Note:  Satellite FM needs to be spaced at
 least 25 kHz from an active terrestrial station.  Otherwise the terrestrial
 station will interfere with you ability to hear the weak satellite down link
 signal.  When the Mir Station tried to use 145.800 as a down link channel
(November 96 - April 97), it was very difficult for stations to hear and
decode packet from Mir because of all of the Terrestrial packet activity on
 145.790.  Fortunately the amount of packet activity in North America in this
 part of the band has been reduced.

Program your radio for all of the published pairs of channels, and remember
 that all of the pairs are odd splits.  This may require you to get out your
 manual to program the Odd-Split frequencies correctly.  Also program in a
 fourth channel for 145.800 Simplex or Published Down-Link channel.  This
simplex can be used for a couple of things, such as politely telling the
other guy calling the NASA Down-link Space Shuttle channel, that the Shuttle
 is not working Simplex.

The NASA Space Shuttle uses a 4 watt FM radio with a 1/8 wave dipole stuck
 to the Inside of a radiation resistant window on the Shuttle (by comparison
 the Russian Space Station MIR uses an adjustable 5 - 45 watt Kenwood TM-733
 and TM-V7A radio with a 1/2 wave mobile antenna mounted outside the space
 station).  The down-link signal from the Shuttle will usually be much weaker
 than the Mir Station.  The Shuttles window configuration will form the RF
signal into a crude spot light pattern.  If the window of the shuttle is
pointing towards your house, you may hear the signal quite good.  If the
shuttle window is pointing off into space, the RF signals from the Shuttle
 will be very weak.

Doppler corrections:
If you wish to compensate for Doppler frequency error, you can do so my
 programming in additional channels.  Not all radios have the ability to
 compensate for Doppler.  Fortunately the Doppler frequency error on the
 2-meter band is not too much of a problem (plus and minus 3.5khz
frequency drift).  When using the FM mode, you do not need to get your
frequencies exact.  A frequency  error of 2khz or less with work great.

If your radio can be programmed in 2.5 kHz channels steps then program
in the following channels.
               RX        TX
Voice               145.802.5 144.478.5
Voice               145.800        144.470
Voice               145.798.5 144.472.5

If your radio can be programmed in 2/0 kHz channels steps then program
in the following channels.
               RX        TX
Voice               145.802        144.478
Voice               145.800        144.470
Voice               145.798   1    44.472

If your radio can be programmed in 5 kHz channels steps then program
 in the following channels.
               RX        TX
Voice               145.800        44.470

Repeat the process for all channels valid in your area.

Voice Contacts:
I suggest that you have a tape recorder handy when trying to contact the NASA
 Space Shuttle and record you calls to the Shuttle.  There are normally
hundreds of people calling the shuttle at the same time, the recorder will
 help you prove to your self that the voice from space actually said you call
sign.

During one of the Shuttle Atlantis flights, I was able to hear the Shuttle
 on many passes with just a 5/8 wave whip (while the shuttle was directly
over head).  A good base antenna or beam will work a lot better.  The trick
 to working the Shuttle is to find out what channel pair they are using on
this pass.  Listen very closely the conversation coming from the Shuttle.
Listen for Call signs and if your radio can easily switch to receive on the
 Up-links, then switch to the up-link channels and listen for the same call
 sign.  You have to switch quickly between all multiple up-link channels.
Guaranteed someone will try calling NASA Space Shuttle on published down-link
 channel, if this happens, be polite and tell him to QRX.  Not everyone has
access to the correct information.

When you find the correct up-link channel, put your radio back into the
correct Transmit and Receive mode (you don't want to get your splits reversed).
  Listen for the end of a Voice contact and then call the NASA Space Shuttle
 and say your call sign twice and only twice.  Do not send any other
information until you have established a two-way acknowledge.
Listen very closely for your call sign and good luck.  After you have
established a contact, please keep it short.  When you log the
information, make sure you use UTC time, otherwise when you QSL
 they may not find you in their log.  Check into you local Web
or BBS for the current QSL information.

Another good trick to accessing the Shuttle, is to try to time
you choice of passes for some OFF-Hours.  The worst time to call
 the Shuttle is during the Weekends.  Early morning and Weekday
passes when most people are at work  or in bed sleeping are better.

Tracking the NASA Space Shuttle:
Tracking the Shuttle can be very difficult unless you have a
tracking program in you computer and an actuate set of Keep
data for you tracking program.  There are several good programs
 on the market today and they are all very good at predicting the
 next good satellite pass.  The data used to tell the program where
the Shuttle is in orbit, is called Keplerian Elements or KEPS for short.
  The orbits of most satellites do not change much from day to day, and
 month old KEPS are usually ok for most satellites.  This is not true for
 Manned satellites, you need to update your KEPS daily for the Shuttle and
 Weekly for the MIR station.
The reason for the frequent updates is because the Shuttle is constantly
adjusting its orbit with engine firings and attitude control thruster
burns.  Every  time there is engine burn the Shuttles orbit will change
 a little or a lot depending on the duration of the burn.  These changes
 will effect the prediction times of your tracking program.  The pass
predictions times for week old KEPS for the Space Shuttle may off by
several hours.  If you update your Shuttle keps 2-3 times a day off
 the Web you will have better success at making a shuttle contact than
 the guys with 2-day old shuttle keps.

Here is one of many web pages you can get current satellite KEPS.
You can also get current KEPS from AMSAT and NASA web pages.
http://celestrak.com/

Collecting KEP data from Amateur Radio packet BBS system is also a
good source for most satellites.  However, the data from the Packet
 BBS system is usually several days old, while this KEP data is good
 for unmanned satellites, the data may be too old to be of any use for
 accurately for tracking the Space Shuttle.


Orbit Inclination:
The orbit inclination numbers for a satellite will tell you how far above
 and below the equator the satellite will be flying.  The Shuttle usually flies
 at 28 degrees for most missions and at 51 degrees for Mir and ISS missions.
The inclination is very important, because it gives you an idea if the shuttle
 will ever pass over your house.  The 51 degree inclination missions cover most
 of the world.  The lower 28 degree inclination orbits will favor those that
live
 below 30 degrees latitude.

Next Mission:
The next SAREX shuttle will be called STS-93.  It is tentatively planned for
 launch in July 1999.
The orbit will be a 28 degree inclination.
The SAREX package is planed to support both Voice modes and Standard
Terrestrial AX-25 Packet.

Good luck working the Shuttle and MIR, I hope this information is of
some help.  Check your favorite satellite web for bulletins about the
Shuttle.

73 and good DX Miles WF1F @ K1UGM.MA.USA.NA.


Copyright 1999 Miles Mann, All Rights Reserved.  This document may be freely
 distributed via the following means - Email (including listservers), Usenet,
 and World-Wide-Web.  It may not be reproduced for profit including, but not
limited to, CD ROMs, books, and/or other commercial outlets without prior
written consent from the author.
Images received from the MAREX-NA SSTV system on the Russian Space Station
Mir are considered public domain and may be freely distributed, without prior
permission.


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