AMATEUR RADIO ON THE INTERNATIONAL SPACE STATION—
PHASE 2 HARDWARE SYSTEM
Frank H. Bauer; KA3HDO, Sergej Samburov, RV3DR, Lou McFadin, W5DID; Bob
Bruninga, WB4APR and Hiroto Watarikawa, JJ1LYUINTRODUCTION
The International Space Station (ISS) ham radio
system has been on-orbit for over 3 years. Since
its first use in November 2000, the first seven
expedition crews and three Soyuz taxi crews
have utilized the amateur radio station in the
Functional Cargo Block (also referred to as the
FGB or Zarya module) to talk to thousands ofstudents in schools, to their families on Earth,and to amateur radio operators around the world.
Early on, the Amateur Radio on the International
Space Station (ARISS) international teamdevised a multi-phased hardware development
approach for the ISS ham radio station. Threeinternal development Phases---Initial Phase 1,
Mobile Radio Phase 2 and Permanently
Mounted Phase 3 plus an externally mounted
system, were proposed and agreed to by the
ARISS team.
The Phase 1 system hardware development
which was started in 1996 has since beendelivered to ISS. It is currently operational on 2
meters. The 70 cm system is expected to beinstalled and operated later this year.
Since 2001, the ARISS international team haveworked to bring the second generation ham
system, called Phase 2, to flight qualification
status. At this time, major portions of the Phase
2 hardware system have been delivered to ISS
and will soon be installed and checked out.
This paper intends to provide an overview of thePhase 1 system for background and thendescribe the capabilities of the Phase 2 radio
system. It will also describe the current plans to
finalize the Phase 1 and Phase 2 testing in Russia
and outlines the plans to bring the Phase 2
hardware system to full operation.

HAM RADIO EQUIPMENT SPECIFICS
Ham Station Location
The ISS Ham radio equipment will reside in two
locations inside the ISS and at least one location
outside the ISS. 2-meter (144 MHz) operations
will primarily be conducted inside theFunctional Cargo Block (FGB), named Zarya,using antennas that supported docking of the
FGB with the Russian Service Module. Theseantennas, designed for use near the 2-meter
band, (see figure 1) no longer support docking

FGB 2 Meter Antenna Locations
Figure 1
and can be used by the ARISS teampermanently. This is the current location of the
2 meter portion of the Phase 1 ISS ham radio
station. The FGB radio system represents aminimal capability that allows the ARISS teamto support school group contacts and packet
communications on one band, the 2-meter band.
The ARISS team’s vision of supporting several
different international users at the same time on
separate frequency bands and different modes(voice, data, television, etc) requires several
different antenna systems. The ARISS-Russia
team, led by Sergej Samburov, RV3DR,

and school students using handheld systems thatcan be moved throughout the ISS. It will also
support communications experimentation thatwill enable students and radio amateurs toreceive telemetry data from ISS.
Phase 1 Hardware Overview

ARISS Hardware in Service Module
Figure 2
provided this foundation through the installationof four ham radio antenna feedthrough ports on
the Russian Service Module.
With theseantennas in place, the primary location of theham station will reside inside the RussianService Module (SM) named Zvezda. The ham
station will be installed near the SM dining table.
See figure 2.
Simultaneous multi-band
operations can be conducted with these two (SMand FGB) station locations.
The ARISS team is also working with theinternational space agencies to install externallymounted amateur radio equipment on the ISS.
This hardware will enable the crew tocommunicate with Earth-bound radio amateurs

The ARISS team has developed all the hardware
elements for the Phase 1 radio system. These
hardware elements have been flown to ISS on
three Shuttle flights. The Phase 1 system
supports voice and packet (computer-tocomputer radio link) capabilities. Packet radio
has several capabilities including an APRSInstant Messaging-type system and a Bulletin
Board System that allows radio amateurs to store
and forward messages and allows the orbiting
crew to send e-mail to all hams or to individuals.
The Phase 1 ham radio system was developed
primarily in the US. However, extensive testing
and coordination with the ARISS-Russia teamwas required since it is installed in the ISS
Russian segment. The initial portion of thePhase 1 ISS Ham radio system was launched onboard the STS-106 Space Shuttle Atlantis
mission on September 8, 2000. This system
consists of two hand-held Ericsson MP-A
transceivers for 2 meters and 70 cm, a power
adapter, an adapter module, an antenna
system, a packet module, a headset
assembly, and the required cable
assemblies (see figures 3, 4 and 5).
This configuration can be operated in theattended mode for voice communications
andeithertheattendedorautomatic mode forpacketcommunications.

ISS Ham Phase 1 System in the FGB
Figure 3

Additional ARISS
Phase 1 hardware
wasdeployedduringtwo
additional Shuttle
flights to ISS. This

Ericsson Radio
Figure 4hardware included an
additional
PacketModule on the STS-105
Discovery flight on
August 10, 2001 (seeFigure 6), and additional
cables and modules tosupport simultaneous 2
meter and 70 cm
Phase 1 Hardware
operation on the STSFigure 5
108 Endeavour flight on
December 5, 2001.
Details of the Phase 1 system are described inreference 1.
Antenna Assemblies
In 2002, a set of four antenna systems,
developed by the ARISS team, were deployedduring three Russian EVAs. These antennas will
support the Phase 1 and Phase 2 systems in theService Module.
Once checked out, thespecially designed antenna assemblies will
permit operations on HF (20 meters, 15 meters& 10 meters), VHF (2-meters), UHF (70cm),
and the microwave bands (L and S band) Theseantennas also permit the reception of the Russian
Glisser EVA video signals (2.0 GHz). This
dual-use (Ham/EVA video) capability is theprimary reason the ARISS team received access
to
the
four
antennafeedthroughs
located on theoutside of theService Module.
A total of fourantenna systems
were developed
to get maximum
use
of
the
antennafeedthroughs.
Antenna Location from
These
were
End of Service Module
installedaroundFigure 7
the periphery of
the far end of the Service Module. See figure 7.
Three of the antennas (WA1-WA3) include a

Phase 1 Packet Module
Figure 6

VHF/UHF flexible
tapeantennas.
WA4 includes a
2.5 meter flexible
tape HF antenna.
Theantennasystems
weredeveloped by the
U.S., Italian, andRussian
ARISS
partners.

Each antenna assembly consists of a mounting
plate, spacer, a black striped handle, a Russian
handrail clamp, an orange-colored VHF/UHF (orHF) metal flexible tape antenna with black delrin
mounting collar, an L/S band flat spiral antenna
with a white delrin radome cover, a diplexer(mountedunderneaththeplate)
andinterconnecting RF cables. See figure 8.
Theantennasystemswerelaunched
on
the
Space
ShuttleAntenna Systems WA1-WA4
Endeavour
Figure 8flighton
December 5, 2001. The two up-looking (zenith)antennas, WA3 and WA4, were deployed by
EVA (space walk) in January 2002 and the two
down-looking (Nadir) antennas, WA1 and WA2,
were deployed by EVA in August 2002.
Antennainstallation
EVA
proceduredevelopment and training was led by Sergej
Samburov from Energia with support from the
ARISS-USA team.
PHASE-2 HARDWARE SYSTEM
Phase 2 Hardware Overview
The Phase 2 hardware system is expected to
exploit the new antenna systems installed on theService Module. Two new radio systems will beinstalled as part of Phase 2. These systems willaugment the two Ericsson radio systems alreadyon-board the ISS as part of the Phase 1 system.
Combined, the Phase 1 and Phase 2 system will
provide more capabilities for the crew andpermit simultaneous, multi-mode operations by
more than one crew member.
The Phase 2 development is a joint Russian, U.S.
and Japan activity. Development was led by
Russian team member Sergej Samburov,
RV3DR. The Russian team was responsible forcertifying the hardware for flight and providing
the ride on the Progress launch vehicle. The
Japanese team provided (donated) the Kenwoodradios to the ARISS team and made specifichardware and firmware modifications to theradio system to prepare it for flight. The USA
team, in conjunction with the Japan and Russianteam, developed the Program Memory softwarethat provides a powerful system with a very
user-friendly interface for crew.
One of the two radios qualified for flight is a
Kenwood TM-D700 radio. This radio supports
2 meter (144-146 MHz) and 70 cm (435-438
MHz) transmit/receive operation and L-band
uplink operation. This radio provides a higher
output power capability (10-25 Watts) than the
Phase 1 radio system and can support FM andpacket operations. The higher power capability
should allow nearly horizon-to-horizon signal
reception using simple hand-held radios orscanners.
The other radio is a Yaesu FT-100. This radio
system will permit operation in the highfrequency bands.
Of particular interest is
performing
ionosphericpropagation
experimentation using the WA4 (highfrequency) antenna and this radio. This radio
also supports higher output power capabilities on
2 meters and 70 cm.
The entire set of Phase 2 hardware consists of
the Kenwood and Yaesu radios, an RF tuning
unit for the Yaesu radio system, interconnecting
signal and RF cables, two specially developed
Energia power supplies, a power distribution

Phase 2 Hardware Housed in
Velcro Table
Figure 9
assembly developed by the USA team, acomputer and the 70 cm Phase 1 hardware
system. These will be mounted on a Velcrobacked table. See figure 9. These radio systems
will be connected to the four Service Module
antenna systems through a Russian developed
antenna switching system. See figure 10. A
schematic of the hardware configuration isshown in figure 11.
WA1

WA2

WA3

WA4

RF Switching
Assembly

Antenna
Tuner
Glisser
Kenwood
D-700E

Glisser

Phase 1
(Ericsson)
70 cm

2m/70 cm

Glisser

Glisser

HF
Yaesu
FT-100RF Layout of ISS Ham Radio Systems
Figure 10
Kenwood D-700 Specifics
The ARISS and Kenwood teams agreed that the
Kenwood European model radio, D-700E, would

Phase 1
Ericsson
70 cm

Yaesu
FT-100Power
Supply 2

Spares 70 cm

FT-100Kenwood
D-700EPower
Supply 1

D-700

Power Distribution AssemblyPower
Receptacle

Power Distribution Schematic
Figure 117) Incorporating a channel designator for
the front panel as the default instead of
the frequency information.
The architecture of the radio interface to thecrew was carefully crafted by the USA andJapan team to make the D-700 a powerful radio
system with a simple user interface. A set of 5
default options, or Programmable Memories,
were embedded in the D700 to support ISS
operations. See figure 12. The advantage ofthese five Program Memories (PM’s) are thatthey can be restored with a two-button key pressby the crew at any time. With the two hundred
different frequency channels, the nearly one
hundred TNC parameters, and the variety of
applications for this radio on orbit, the default
configurations are absolutely critical to being
able to maintain communications with the crew
under all conditions. These five configurations
reduce operations to these fundamental
configuration baselines:

be used for flight and ground operations. This
radio was already certified by the Russian team.
Several modifications were made by the
Kenwood Japan and Kenwood Moscow(Bermos) teams to prepare this radio system forflight. These included:1) Developing a special Memory Control
Program(MCP)
tosupportreprogramming of the radio in the USA,
Japan
and
Russiato
ARISS
specifications
2) Changing the packet radio default
parameters, as specified by the ARISS
team, in EEPROM memory3) Enhancing the “repeater mode” of theradio system
4) Replacing the power cable and themicrophone and control head cables withflight cables to allow certification of the
hardware to the Russian requirements.
5) Reducing the maximum power output of
the radio to 25 watts
6) Replacement of the 6-pin data connector
with an 8-pin connector. One of theadditional pins on this connector supports
an 8 V DC output capability.

Kenwood D-700
PM1 Crew Display
Figure 12
PM1: Voice Operations (mono band)
PM2: Voice Operations (cross band/repeater)
PM3: APRS/Packet and BBS operations
PM4: Attached PC and packet operations
PM5: Emergency Voice and alternate 9600
baud Packet Operations.
PM-off:No defaults. This mode is forknowledgeable licensed crew member’s
experimentation
The PM’s remember the following types ofparameters for the radio:

•
•
•
•

Default Channel for LEFT side and RIGHT
side of radio
Which side of radio the Microphone and
PTT will activate
Which side of the radio the TNC will
RECEIVE and on which side it will
Transmit
The function of the several “soft keys” on
the radio front panel

While the MCP program stores all 200
frequency channels in the radio, the PM’s do notstore any combination of channel frequencies
other than the initial two defaults for the left andright side of the radio. This means, that once a
PM has been selected by the crew, this only
configures the radio to a known default pair ofchannels. The crew member can still tune toany channel after that. Thus, with a push of two
buttons and a rotation of the main dial, the crew
member can operate on multiple modes anddifferent frequency pairs.
While thisarchitecture offers the ultimate in flexibility(millions of combinations), it also provides auser-friendly interface of the five PM’s toalways return the radio to a known initial state.
Each of the 200 memory channels can support
separate TX and RX frequencies, offsets, andPL or CTCSS tones. The D700 is a dual radio
system and although it only supports twochannels at a time, it is very important toremember that each channel consists of both adisplayed RECEIVE frequency and a separate
TRANSMIT frequency. Thus, at any time,
there can be up to four frequencies involved inradio operations. Since the Microphone andPTT (for voice) can be using one channel andthe TNC can be using the same or the otherchannel, or even can transmit on one channel
and receive on the other, there are many
conventional (e.g. simplex, split) and nonconventional (e.g. crossband, repeater, CTCSSenabled command uplink digital channels, etc)
ways to use these combinations for ARISS.

Yaesu FT-100 Specifics
The ARISS technical team working on the
Yaesu
projecthas
specified
severalmodifications to the Yaesu radio system toprepare it for flight.
These modifications
include:1. Replacing the power cable and themicrophone and control head cables withflight cables to allow certification of the
hardware to the Russian requirements.
2. Reducing the maximum power output of
the radio to 25 watts
3. Replacing the PVC RF cables andconnectors on the back of the radio with
SMA connectors. Attached to these are
Teflon coated RG-142 antenna cables
with N connectors
4. Tuner cable replacement with flight
cables
5. Replacement of 6-pin data connector
with an 8-pin connector. One of theadditional pins on this connector supports
a 12 V DC output capability.
Since the FT-100 supports HF operation and theWA4 antenna is a single 2.5 meter vertical the
ARISS team felt that it would be best to supply atuner with the radio to minimize SWR concernsand optimize signal output. See figure 11. The
ARISS USA team is working closely with theYeasu team to modify their existing FT-100
auto-tuner for ham radio operations on ISS.
Development of the Yaesu system is on-going,but is expected to conclude in early November
2003.
Power Distribution Assembly
One of the primary issues in a household is
sufficient and easy access to electrical
receptacles. A similar issue exists on ISS.
There just aren’t enough receptacles where youneed them. With the 3 radio systems being
installed in the Service Module (Phase 1 70 cm,
Phase 2 Kenwood and Phase 2 Yaesu), the needfor electrical receptacles for the ISS ham radio
system could become a major issue.

The power distribution assembly, see figures 11
and 13, resolves this problem and several otherpotential issues on ISS. The power distribution
assembly allows the ISS ham system in theService Module to be plugged into only one ISS
receptacle. It also provides a power shutoff
capability via switches and circuit breakerprotection for each radio system. This not only
provides an addition level of safety but also
provides an additional shut-down feature that is
critical for satisfying the ISS EVA safety
requirements.
With the power distribution
assembly, there will be no need to plug andunplug ISS Ham items due to insufficient
receptacles. Thus, this assembly serves toreduce wear and tear on the power cables,
improving system safety.

Power Distribution Assembly
Figure 13
The Power Distribution Assembly is being
developed by the USA team with strong support
from the Russian team. While the unit will befabricated in the US, several of the parts,
particularly the electrical connectors, are
Russian supplied. The current plan for thePower Distribution Assembly is to fabricate theflight unit, certify it for flight in the US and in
Russia and then fly it on-board the next space
shuttle. Since the Yaesu system will not be
deployed until the Spring of 2004, thisdevelopment and delivery schedule appears tomake sense.
Power Converters
Two fully redundant, flight certified power
converters were developed by the Russian
Energia team and were supplied to the ISS Hamteam for use as part of the Phase 2 radio system.

These power
supplies
convert the 28
VDC
ISS
power to 13
VDC for use
bythePower Converter
Kenwood andFigure 14
Yaesu
radio
systems. Since
the power converters are fully redundant, the ISS
ham team will have adequate power capabilities
for all the radio systems even if one of the power
converters fail.
Phase 2 Delivery, Testing and Checkout
The final version of the flight MCP software wasdelivered to the Russian team by the USA teamon July 17, 2003. Just prior to this, theKenwood Japan team delivered the final
firmware load to the Kenwood Japan (Bermos)
team for installation into the D-700 radio. The
Bermos team and the ARISS-Russia team, led
by Sergej Samburov, completed the hardware
and software modifications to the radio system
in late July and readied the Phase 2 hardware
system for flight. The initial set of Phase 2
hardware, including the Kenwood D-700 radio,
interconnecting cables, power converters, andRF switching system were delivered to the
Baikonur Cosmodrome in Kazakhstan in earlyAugust. The Phase 2 hardware was launched on
the Progress 12P rocket on August 29, 2003 anddocked with the ISS on August 31. The Velcro
table is already on-board ISS and is awaiting
equipment installation.
The Phase 2 equipment is currently “yellow
tagged” meaning that we need to accomplishsome additional tests prior to on-board hardware
integration and testing. A series of tests arebeing planned for early November, 2003 at the
KIS facility (Service Module engineering model
equivalent) located at Energia in Korelev(Moscow area) Russia. The Russian and US
team will be conducting tests in this Service
Module equivalent to validate that the Phase 2
and 70 cm and 2 meter Phase 1 systems arecompatible with the other electrical systems on
the Service Module. We will also conduct some
RF testing with the flight-identical antenna
systems and the Phase 1 and Phase 2 hardware.
Once these tests are successfully completed, theyellow tag can be removed and hardware
installation can begin.
The current plan is for Mike Foale andAlexander Kaleri to install the Phase 2 andPhase 1 70 cm hardware on Expedition 8. The
plan is to perform hardware installation andcheckout in mid to late November 2003.
The remaining Phase 2 hardware, including theYeasu radio system is planned to be launched on
the Progress 14P flight that is planned forJanuary 2004.
FUTURE HARDWARE DEPLOYMENTS
Follow-on Phase 2 Hardware
Two future projects are envisioned to improvethe capabilities of the Phase 2 system. These
include the development of the tuner for the
Yaesu radio system and the certification of aStanding Wave Ratio/Power meter. These two
projects will be developed and flight certified by
the US team and flown on a future shuttle flight.

CONCLUSIONSThe ARISS-international team, with help from
Kenwood and Yaesu, have developed the ISS
Phase 2 ham radio system. The Kenwood
system is currently on-orbit and will be soon
operational on ISS. The team expects that theYaesu system will be operational in Spring
2004. This multi-national development effort
presented many challenges to the team. Despite
these challenges, the tremendous teamwork andoptimistic spirit resulted in an outstanding new
capability on ISS that we expect to set thestandard in space for years to come.
ACKNOWLEDGEMENTS
The authors would like to acknowledge thetremendous support, teamwork and volunteer
spirit of the ARISS-International team in making
this hardware system come to fruition.
Technical, financial and administrative support
by the ARISS member organizations--theAMSAT organizations and IARU organizations(ARRL in the USA) continue to be crucial to thesuccess of the program. Also special recognition
is in order to NASA, Energia, Kenwood, andYaesu. The ARISS team continues to beindebted to them for all their in-kind
contributions and support. Together we are
pioneering the new frontiers of amateur radio
and educational outreach.

SSTV
DEDICATIONIn the near future, a Slow Scan Television(SSTV) system will be deployed on ISS. The
SSTV system for the ISS ham radio station iscurrently in development. This system willconsist of a software interface, developed by the
MAREX-MG team and a hardware interface,developed by the AMSAT-NA hardware team.
Prototype hardware and software systems havebeen developed and the flight system fabrication
has started. The SSTV system will allow digitalstill pictures to be uplinked and downlinked inboth crew-tended and autonomous modes. The
ARISS team expects the SSTV system to be
flown on Progress flight 14P in January 2004.

This paper is dedicated to the memory of Roy
Neal, K6DUE. Roy’s tireless pursuit to makeamateur radio on human spaceflight missions apermanent capability was an inspiration to us all.
We feel privileged to have realized his vision on
ISS during his lifetime. We have more solidly
cemented that permanence with the delivery of
the Phase 2 hardware system. Our thoughts andprayers are with you old buddy.

REFERENCES
1. Bauer, F., McFadin, L., Steiner, M., andConley, C., “Amateur Radio on theInternational Space Station---the First
Operational Payload on the ISS.”
Proceedings from the World Space
Congress, 2002
2. Watarikawa, H., and Aota, S., ARISS D700 Users Manual, July 15, 2003
3. Bauer, F. and McFadin, L., “SAREX
Hardware Configurations and Flight
Operations Support” Proceedings of the
AMSAT-NA Tenth Space Symposium,
October, 1992.
4. Bauer, F. and Marchant, W., “AmateurRadio on the International Space
Station,” Proceedings of the AMSATNA Sixteenth Space Symposium,
October 1998.
5. "Joint NASA-Energia Meeting on
Amateur Radio for the International
Space Station Held at Johnson Space
Center, Houston, Texas 22-27 January
1999," The AMSAT Journal,
July/August 1999.
For more information on the ARISS program,
you are welcome to visit the ARISS web page at:
http://ariss.gsfc.nasa.gov or
http://www.rac.ca/ariss