ISS Amateur Radio Antenna status report



May 25, 2000



By Miles Mann WF1F,

MAREX-NA (Manned Amateur Radio Experiment, North American Division)



The long and short term plans for Amateur Radio antennas on the

International Space Station (ISS) are progressing very well.  It was

originally proposed in 1996 by RSA Chief of the Amateur Radio

Cosmonaut Department, Sergej Samburov, to use a temporary navigation

antenna on ISS for the initial antenna for Amateur Radio experiments. 

And then after a few space walks,  a dedicated group of antennas for

Amateur Radio experiments could be installed.  This plan seems to be

working.  The Russian Zarya Control Module, also know as the Functional

Cargo Block (FCB) is currently in orbit and connected to the NASA Unity

module.  There is an existing externally mounted antenna on this module

which was used for telemetry.  Now that the Zarya module is in orbit,

the telemetry antenna is now available for other uses.  I was told by

RSA that the antenna is tuned for approximately 147 mc, which is perfect

for the Amateur Radio satellite band 144.000 - 146.000 mc.

When the first ISS crew moves in later this fall, they will have

immediate access to this antenna port from inside the Zarya module, No

space walk will be required.  The only limiting factor, is when will the

ISS crew be allowed the time to install the amateur radio voice/packet

station.  The ISS crews time line (or work load) is calculated down to

the minute.  You are even assigned times to go to the potty.  During a

recent visit to the European Space Agency, one  person said the ISS

crews would use the Amateur Radio station during their Free time.  Then

another ESA representative then said, There is no such thing as Free

time for the crew while in space.  All of there time is scheduled.  



Limitations:

Since the Zarya module antenna is limited to the 2-meter band, there

will only be 2-meter mono band access for the first year.  This is

actually good news for beginners, since it is much harder to work Split

band 2m/70cm.  The original ISS 2-meter system will operate both FM

voice and 1200 baud AX.25 packet.  This is the same packet protocol used

on Earth for your local BBS access.  This is also the same packet format

used on Mir, however some of the commands may be different.  The Zarya

module 2-meter radio will be limited to approximately 5 watts of

output.  If you have a zero gain antenna, you will be able to get access

on a few passes per day.  A real gain directional antenna system will

improve your link reliability.



Time-Line:

Here is a NASA link for the proposed time line.  

http://spaceflight.nasa.gov/station/assembly/flights/chron.html



When will the Amateur Radio Station on ISS be turned on?

That's a good question. The best guess is a month or two after the ISS

crew moves in. Sergei Konstantinovich Krikalev is part of the first ISS

crew.  Sergej is a real Ham.  He knows the importance of Amateur Radio



for long duration Missions.  I am sure he will do his best to get the

system on line in a reasonable amount of time (crew work load and

permissions permitting).



Next Antennas:

The engineers at RSA really did a great job in planning for additional

antennas on ISS.  The Service module has 4 extra multi purpose antenna



ports installed.  Each one of these empty antenna ports can be used

simultaneously for commercial and amateur radio access.  The

simultaneous access is achieved by properly filtering the signals which

allows 2-3 different signals to share a single antenna port.  Service

Module Antenna port 1 will have three antennas diplexed into one cable,

supporting Amateur Radio bands 2-meters and 70 centimeters and a

commercial 2.4 gig band.  Amsat Italy designed the triband antenna for

port 1.  I do not have any data on ports 2-4 at this time.  The Service

Module is scheduled to be launched this summer (Aug 2000).  The new

ports are just empty antenna feed through ports.  There are no antennas

connected to the ports before launch.  The antennas must be installed

after docking via a space walk.  The space walks to install the Amateur

Radio antennas are not scheduled until the Summer of 2001.  The 2.4 gig

commercial port will be used to receive TV signals from crews during a

space walk (just like in the movie Aliens).  Each crew member will be

wearing a TV camera attached to his helmet.  It may be possible to hams

to hear the weak 2.4 gig signals live, that is if you have 24 dbd of

antenna gain on 2.4 gig.  After the new antennas are installed in 2001,

we will be able to connect additional Amateur Radio experiments to these

ports.  The service module has some cabinet space reserved specifically

for Amateur Radio experiments.  The MAREX-NA team is actively developing

a software version of Slow Scan TV for use on ISS.





See you on Mir and ISS