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ARISS Radio Article

Greetings Fellow Amateurs;

Recently my company asked me to write up an article for the company web site
about the Ericsson radios we built for the ARISS program.  Several of you
helped out by providing me with much-needed information and photos.

The article is on the internal company site now, and it has been passed on
to the corporate people who manage the external site.  It's unknown whether
the "powers that be" well deem the material worthy of placement on the
public site.

One of my major purposes for writing the article was to help educate our
several thousand employees about the importance of the ARISS program
specifically, and Amateur Radio in general.  I tried to avoid using
"HAM-ese" terminology which many readers would not understand.  The article
might not be as technical as we HAMs would normally want, but it's intended
for a general audience.

I'm listing out the article below in plain text form for those of you who
are interested in the final product.  Since the photos are large, I'll not
try and send them through the reflector, which I doubt would let them pass
anyway.  If you would like to have copies of the photos, please e-mail me

Thanks again to all who helped.  I couldn't have done it without you!
Special thanks to the ARISS hardware team!

73, James Alderman, KF5WT

[Note:  "The Company" I'm talking about was GE originally, then it became
Ericsson-GE, then Ericsson, then Com-Net Ericsson, then M/A-Com Wireless.
Sometimes I don't know who I work for...they just keep paying me and I keep
showing up every day!]

* * * * * * * * * * * * * * * * * * * * * *

M/A-Com Wireless Lets Astronauts
"Phone Home" and Chat With School Students

By James G. Alderman, KF5WT
M/A-Com Wireless, Dallas, Texas

    When astronaut Susan Helms wants to "phone home" from aboard the
International Space Station (ISS), she reaches for an Ericsson radio.  As
part of the Amateur Radio Experiment on the International Space Station, or
ARISS, Ericsson (now M/A-Com Wireless) recently donated several custom-built
MPA handheld radios to the project.  Astronauts routinely use the radios to
speak with their families and with school students all over the world.

    The Amateur Radio system aboard the ISS serves an important function as
a back-up communications system in case the main system goes down.  Also,
NASA believes that crew morale and psychological wellbeing are vital during
extended stays in space.  The system serves a valuable purpose by enabling
astronauts to speak with family members back home a few times per week
without burdening the main communications system which is often busy with
"official" NASA business.  These family contacts keep crew morale up as
astronauts are able to hear familiar voices of loved ones on a regular
basis.  (Photo 1 - Susan Helms operating the ARISS radio.)

    For a few lucky science teachers around the world, the ham radio system
aboard the ISS is a dream come true.  A few times per month, astronauts make
pre-scheduled radio contact with school classrooms.  Excited students get to
"interview" astronauts over the radio during these 10-minute contacts while
the station passes over a ground station.    These events always attract
media attention and create lasting memories for all involved.


     The presence of Amateur Radio in space is nothing new.  When satellite
communications was in infancy some forty years ago, amateur radio operators
were busy building their first satellite.  In 1961, just four years after
Sputnik sent shock waves around the world, hams launched the first Orbiting
Satellite Carrying Amateur Radio.  OSCAR 1 was the size of a shoebox and
weighed only 10 pounds.  It carried into earth orbit a simple 100 milliwatt
Morse code transmitter, which was heard by hundreds of radio enthusiasts in
28 nations as it circled the earth for some 20 days.  From those humble
beginnings, OSCAR satellites have become more numerous and sophisticated.
Some 23 amateur satellites are currently operating in earth orbit.  (Photo
2 - Owen Gattiott operates SAREX radio.)

    Although no Amateur Radio experiments were carried aboard the Apollo or
Skylab missions of the 1970s, ham radio often rode along with the first
space shuttle missions in the early 1980s as part of the Shuttle Amateur
Radio Experiment (SAREX).  In 1983, ham-astronaut Owen Garriott  (W5LFL)
made history when he became the first human to operate ham radio from space.
For that momentous first contact, Garriott placed a special antenna against
the window of shuttle Columbia and used a handheld radio to make contacts
with amateurs on earth.  History was made and ham radio has been a
frequently space traveler ever since.  (Photo 3 - SAREX QSL card.)

     Numerous SAREX experiments were conducted on many shuttle flights over
the next fifteen years.  In the beginning, astronauts simply made voice
contacts with hams on earth using that same original 2.5-watt handheld
Motorola radio and window-mounted antenna.  The success of these early
experiments paved the way for packet data, slow scan TV, and broadcast
standard television experiments to be flown aboard later Shuttle flights.

    Although hundreds of hams all over the world enjoyed the thrill of
talking to astronauts in space, the ultimate goal of the SAREX program was
to allow astronauts to communicate with school students for the purpose of
stimulating interest in science.  During the 1980s and 1990s, dozens of
schools on every continent participated in the program, and thousands of
excited students got to take their turn at the microphone and speak directly
to an astronaut.  Because these early experimental school contacts were so
successful, the spirit of the SAREX program was carried over to the ARISS
program when Space Station Alpha was built.  Amateur Radio now had a
permanent home in space.  (Photo 4 - ARISS logo)


    Today, NASA considers Amateur Radio to be so important that a permanent
ham radio station has been planned for the new International Space
Station-complete with its own special storage space for the radios and
outdoor antennas for improved performance.  For the ISS, a totally new
Amateur Radio system has been designed for greater versatility.  (Photo 5 -
Outside view of ISS.)

    The new M/A-Com radios are the workhorses of the new communications
system.  The ARISS hardware team selected the MPA radio because of its
rugged design, long track record of reliability, and ability to meet
stringent emission purity standards.  With so many systems operating aboard
the ISS, every electronic device brought aboard must be thoroughly tested to
insure that it doesn't cause harmful RF interference to other systems.  The
commercial grade MPA passed all tests with flying colors.

    A total of 12 MPA radios were built for the ARISS program-6 VHF and 6
UHF radios.  (Normally these radios cost around $2500 each.).  Why were so
many radios needed?  Training astronauts for space flight, and planning for
future Amateur Radio projects, is a complicated (and expensive) operation
that takes place in various locations.  Therefore the radios are spread out
all over the world.

    One VHF and one UHF radio, along with their support hardware,
constitutes a "set."  One set is, of course, presently located aboard the
ISS.  Two spare sets are located at the Goddard Space Flight Center in
Greenbelt, Maryland where the ARISS hardware development lab is.  If a
problem occurs with the radios aboard the ISS, the Goddard team stands ready
to troubleshoot it using their own MPA radios.

    Star City, the Russian astronaut training facility near Moscow, has one
set of radios, as does the Johnson Space Center in Houston.  The final set
belongs to the Amateur Satellite Corporation (AMSAT) which is the entity
primarily responsible for planning future ARISS programs.  In short, every
set of hardware is being used either for actual communications, astronaut
training, or R&D.  That's a lot of hardware!  (Photo 6 - Diagram of hardware

    In addition to the radios, several pieces of critical support hardware
had to be built to make the whole system work.  One of the most important
items (which had to be custom built) is the Packet Module.  This large white
box contains a special modem to allow data transmissions over the radio, and
a few switches and voltage regulators to enable all the equipment to run off
the space station's 28-volt power bus and interface with accessories.
(Photo 8; Photo 9 - Radios laid out on table for display, and packed up for
shipment it ISS.)

    For packet data communications with stations on earth, an astronaut
simply has to plug a laptop computer into the packet module, turn on the
radio, and "float" away.  In this state, the orbiting packet station can
operate unattended.  An astronaut may return to find an e-mail from home, or
a greeting from a ham on a remote Pacific island.  Hams on earth who contact
the ISS on packet or voice can receive a special postcard to commemorate the
event.  The station is left in unattended packet mode most of the time to
allow a maximum number of hams to make contact.

    At the flick of a switch, the station is ready for voice operation.  An
aircraft-grade David Clark headset is provided for this.  A special
interface box is provided for the headset to plug right into the system.
Astronauts can key the radio with the handy PTT button located on this
interface box while keeping both hands on the clipboard to log radio
contacts.  In short, the ham station aboard the ISS is easier to operate and
more versatile than many home-based stations.

    One very nice feature that the ISS ham station has is an outdoor
antenna-something that the early SAREX station didn't have.  Although this
antenna is less than 2 feet long, it performs superbly, raining a clear
signal down on the earth below.  Stations within line of sight of the ISS
can communicate with astronauts using simple handheld or mobile radios.
(Photo 7 - Large outdoor photo of the ISS with antenna visible.)


    The MPA radio aboard the ISS has 64 pre-programmed channel pairs.  Since
astronauts have a lot on their minds, ARISS hardware engineers thought it
best to set the radios up for easy, pre-channeled operation.  For voice
contacts, the radio transmits on 145.80 MHz and receives on 144.49 MHz.
During packet data operation, the radio transmits on 145.80 MHz and receives
on 145.99 MHz.  (Other frequencies are used when the ISS is over Europe.
See reference section below for more information.)

    For school contacts, the astronauts operate on a special frequency split
to avoid interference from the hoards of ground stations that may be trying
to call the ISS when it's over major land masses.  In this configuration,
the station transmits on 145.80 MHz so that everybody on the ground can
listen in.  (The signal coming down from the ISS is referred to as the
downlink frequency.  Hams on the ground transmit up to the ISS on the uplink

    However, when conversing with a school, the ISS radio listens on a
special confidential frequency-a frequency that is only revealed on a
"need-to-know" basis.  Ham volunteers who set up radio gear at participating
schools are warned that they must take special care to not reveal this
secret frequency-not even accidentally.  Doing so would compromise the
technical integrity of the school contact program.  To avoid accidentally
revealing the frequency, hams avoid allowing real-time live TV camera shots
of their radio displays.  Still photos that show front views of radios are
staged ahead of time with the radio showing only the public downlink
frequency of 145.80 MHz.


    Although talking to astronauts is an exciting proposition for Amateur
Radio enthusiasts around the world, the ARISS program actually has a deeper
purpose.  Like the SAREX program before it, the primary purpose of the ARISS
program is to stimulate interest in space, technology, and science among
school students.  Since the M/A-Com radios have been aboard the ISS, about
15 school contacts have been conducted, and some 200 students have asked
astronauts questions on every subject from what it feels like to be
weightless to how trash is recycled in space.

    For a school, the opportunity to let students talk to astronauts in
space via ham radio is a highly sought-after activity that requires an
enormous amount of preparation.  To begin with, the waiting list is over two
years long, and not every school that applies is chosen to participate in
the ARISS program.

    A school must have a sponsoring teacher, a host of ham volunteers ready
to set up the radios and antennas, a dynamic science program (which includes
space studies), and they must conduct a whole host of space-related projects
and activities in conjunction with the radio contact.  In short, only the
most deserving and enthusiastic schools are chosen for an ISS contact.
Once a school has been chosen to participate in ARISS, preparation for the
10-minute event takes months of hard work.  A primary and backup radio and
antenna system must be installed at the school, and computers must be loaded
with tracking software so ham volunteers can keep an array of steerable
antennas locked onto the ISS as it passes some 230 miles overhead.

    Although it is possible for anyone to hear the 5-watt signal from the
ISS using only a common handheld radio or scanner, special high-gain
antennas are used for school contacts.  This is done to insure clear
communications during the period when the ISS is just coming into range, and
just flying out of range-periods when the signal would normally be weak.
Since the ISS is only within range for a maximum of 10 minutes, every minute

    While ham volunteers are taking care of all the technical details,
students have their own preparation to do.  Normally the schools hold a
contest to see which lucky students will get a turn at the mic.  Though the
exact selection methods vary from school to school, students usually must
submit their proposed questions to a panel of teachers who choose the most
interesting questions to have the astronauts answer.  Then each lucky
student must practice his or her "lines."  The students are coached on how
to speak clearly over the radio, including how to say "over" at the end of
their transmission.

    School contacts are always big media events.  Parents and community
leaders are always on hand too.  As the moment of AOS (acquisition of
signal) approaches, directional beam antennas are aimed at the point where
the ISS will first break over the horizon, and radios are readied.  Then out
of the noise, right on time, a voice crackles forth from the radio speaker.
"This is NA1SS calling on schedule."  It's astronaut Susan Helms-loud and

    Over the next 10 minutes one nervous student after another speaks into
the mic and asks Susan a question.  As a computer screen continuously
displays the station's location in orbit, motorized antennas outside the
school building slowly track the tiny dot in the sky and keep a perfect lock
on the station.

    The activity continues, and the signal from 230 miles in space remains
strong until the ISS slowly drops below the horizon beyond line of
sight...then it's gone.  The adventure is over.  Students, teachers, and
parents all go away changed; forever awed by their wondrous experience made
possible by the ARISS program.  It's not uncommon for teachers to tell of
marginal students who developed a love of science and technology after an
ARISS contact.  And that's the whole purpose of ARISS-to inspire young


    These educational activities are heart and soul of ARISS, and plans are
now underway to expand the capabilities of the ISS ham radio station.  In
early 2002, the ISS will be equipped with a multi-band antenna, which will
allow additional operation on two microwave bands (1296 MHz and 2400 MHz),
and at least one high-frequency (HF), or "short-wave" band antenna.
It's expected that astronauts aboard the ISS will some day be able to
communicate with stations on the other side of the world using short-wave
signals, which bounce around earth on upper layers of atmosphere.
Additional radio gear is being developed now to do all this, and more.  The
future of Amateur Radio in space is bright indeed!

    The International Space Station is mankind's first step towards
exploration of other planets and deep space.  Perhaps moon colonies will be
established in the coming decades.  Many great minds will be needed to make
it these dreams a reality.  Amateur Radio stands ready to inspire them.

    Perhaps one of these students who spoke to an astronaut via ham radio
may grow up to be the first human to set foot on mars.  Whatever the future
holds for mankind, you can be sure that Amateur Radio, and M/A-Com Wireless,
will be there, bringing the wonders of space exploration down to earth for
all to share.


ARISS Home Page: http://ariss.gsfc.nasa.gov/ or
ISS Operating Frequencies:  www.amsat.org/amsat/news/wsr.html
MAREX Home Page: www.marex-na.org
Amateur Satellite Corporation (AMSAT):  www.amsat.org
National Association For Amateur Radio (ARRL):  www.arrl.org
Heavens Above - Sighting opportunities:  www.heavens-above.com
NASA Spacelink - On-line educational and curriculum material
including "Amateur Radio in Space - An Educator's Guide":


* Boy Scouts interview astronaut Susan Helms aboard the ISS during their
recent National Jamboree.  See photos and hear a Real Audio clip:
* National Association For Amateur Radio is establishing a grant program to
put Amateur Radio in every Middle School in America at no cost to the
schools.  Learn about the first pilot school to participate in this program:
* A high resolution photo of astronaut Susan Helms operating the Ericsson
MPA radio can be seen on this NASA site:
* The Ericsson radios can be seen ready for shipment to the ISS in this
story: http://www.arrl.org/news/stories/2000/09/06/1/
* Elementary school students in tiny George West, Texas had to get up early
to make their ARISS contact.  Here's their story:
* Klamath County Schools in Klamath Falls, Oregon have active Amateur Radio
programs in elementary through high school grades.  They have so far
participated in one SAREX and one ARISS contact.  Learn more:
*  Burbank County Schools spoke with astronaut William Shepherd then got
another special treat-a visit from William Shepherd:


PHOTO 1 - Astronaut Susan Helms is seen here operating the Ericsson MPA
radio from aboard the International Space Station.  The radio is attached to
the wall with Velcro in the upper left portion of the picture.  A
high-resolution version of this photo can be seen on the NASA web link
listed in the Reference section below.

PHOTO 2 - In 1983 astronaut Owen Garriott (W5LFL) first operated Amateur
Radio from space aboard shuttle Columbia on mission STS-9.  He used a
2.5-watt Motorola handheld radio and a special antenna attached to the
inside of the orbiter's window with Velcro.  The Shuttle Amateur Radio
Experiment proved the viability of Amateur Radio in space and laid the
groundwork for future deployment aboard the International Space Station.

PHOTO 3 - The Shuttle Amateur Radio Experiment brought ham radio aboard the
space shuttle.  These experiments proved (to the delight of thousands of
school students) that even low-powered ham radio signals could reliably
reach the earth from space. Students and astronauts are seen conversing in
these photos.

PHOTO 4 - Amateur Radio on the International Space Station, or ARISS, is
dedicated to maintaining a permanent ham radio presence in space.

PHOTO 5 - The International Space Station is so large (and getting larger)
that is can be seen from earth with the naked eye passing overhear in the
pre-dawn and early evening hours.  The station appears as bright as a planet
but moves in and out of sight during a 5-10 minute period.  For sighting
opportunities, see the Heavens-Above web site listed below.

PHOTO 6 - This diagram shows the layout of the Amateur Radio station aboard
the ISS.

PHOTO 7 - Can you locate the Amateur Radio antenna on the International
Space Station?  Look on the lower side of the station to the left of the
solar array.  A diagonally sloping bar can be seen protruding from the
station out into space.  That's the antenna!   Additional antennas are
planned for the future.

PHOTO 8 - The radio gear is seen here packed away ready to be loaded aboard
the shuttle for shipment to the ISS.

PHOTO 9 - The radio gear is seen here spread out for easy viewing.  The
large white box on the left is the all-important Packet Module.


    James Alderman, KF5WT, has worked in the wireless industry for 15 years
and currently works in the Dallas office of M/A-Com Wireless.  He was first
licensed at age 13 and has been an avid ham operator ever since.  James is
active in several Metroplex-area ham radio clubs, and enjoys showing off the
virtues of the hobby at community and civic events, Scout meetings, and

    James also enjoys writing ham-related and current affair editorial
articles, and most recently wrote "Demonstrating Amateur Radio to the
Public" for the August issue of QST magazine.  James recently taught a
seminar on the same subject at the Ham-Com 2001 convention in Arlington,
Texas.  He can be reached by phone at the Dallas office, on the internal
e-mail network, or at kf5wt@arrl.net.

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