"Reprinted with permission from the March and April, 1998 issues of CQ VHF magazine, (c)

1998, CQ Communications, Inc."

February 23, 1998

by Miles Mann

 Many of you have heard about the Amateur Radio Station on board Mir. What you may not be aware of is how much work goes on in the background to keep the Mir Amateur Radio Station working.

The Russian side of the program is known as MAREX-RU (Mir Amateur Radio Experiment Russia). All projects for the MAREX-RU team run by Sergej Sambrouv (Chief of the Amateur Radio Cosmonaut Department RV3DR) must approve Mir. The MIREX team "Mir International Amateur Radio Experiment" was formed in 1990 by Dave Larsen N6CO (formally N6JLH) and Miles Mann (WF1F). In May 1998 the MIREX club split into two different groups. The MIREX team is still headed by Dave Larsen. The hardware portion of the group formed the MAREX-MG (Manned Amateur Radio Experiment, North American Division). The hardware team headed by Miles Mann continues to build and fly new projects for the Russian Space station Mir and the International Space Station.

 The MAREX-MG team is made up of a group of volunteers who help provide the additional support required to help keep the Amateur Radio equipping operating. For the past 7 years, MAREX-MG has been assisting in the maintenance of the equipment on Mir as well as providing additional in-flight training for the crewmembers. Most of the original Amateur radio equipment on Mir came from the SAFEX group in Germany. This equipment includes a 2-meter FM packet station and a popular 70cm FM repeater. Getting this equipment launched into space was not an easy task. The SAFEX group did an excellent job in forging new territory into the Russian space program. Now beginners around the world had easy FM 2-meter mono-band access to an "Easy-Sat."

 One of MAREX-MG’s challenges has been getting new Amateur Radio equipment to Mir, but even greater is keeping it working. The difficulty in getting the equipment working is due to the crews work schedule. Every 5 to 6 months there is a crew change on Mir. A new crew replaces the existing crew. There is a short period of time when both crews are living together in the same cramped quarters of Mir. Sometimes there may be as many as 6 people are living on board Mir for up to 4 weeks at a time during the crew changeover. MAREX-MG will sometimes run a pre-arranged school schedule during the crew changeovers. This allows the old crew to show the new crew how to run the Amateur radio equipment and run a school schedule.

 Training the new Mir crewmembers while they are in orbit has always been a problem. Each crew does receive some training on the ground before their mission. The amount of ground training the crew receives is directly proportional to the amount of "Up-time" on the Mir Amateur Radio station. Some of the Russian crewmembers even have their own Amateur Radio licenses. When MAREX-MG is dealing with crews who have had previous Amateur Radio experiences, it is easier to keep the equipment working.

Another problem occurs when the equipment begins to fail due to old age. After 2 full years of reliable service, the original PacCom modem began to fail. It seemed the memory battery in the modem had gone dead. The modem would periodically crash (especially during solar flares) and then loses all of the TNC parameters. The battery was soldered into the modem and therefor it was not practical for the crew to replace the battery in flight. The MAREX-MG team decided it was better to implement a program to periodically replace the Amateur Radio equipment on a regular basis, rather than wait for the next failure. Every 3 to 4 months, Energia launches a new unmanned supply cargo rocket called the Progress, to the Mir Space station. MAREX-MG then made arrangements with MAREX to deliver a replacement PacCom HandiPack modem to Mir on the next convenient Progress. The new modem, which we will call PacCom-2, arrived in 1994 and was immediately put into service on the 2-meter Personal Message System (PMS) on Mir. The MAREX-MG team decided to make plans to replace the PMS modems every two years, to help prevent modem hardware failures. The modem problems we were having had nothing to do with defective equipment. It was more to do with the harsh space environment. We were using "Off-the-Shelf" amateur radio hardware, which was not "Radiation Hardened."

The next hardware delivery opportunity for the MAREX-MG would be in the summer of 1997. Many hours of advance planning are required to fly hardware into space. Sometimes flight ready hardware must be delivered to Moscow a whole year in advance.

The MAREX PMS was a very popular Amateur Radio packet station, in-fact, it was too popular. The PacCom modem only had 13 kilobytes of memory available for message storage. During a good day, it was not unusual for the PMS mailbox would fill up in 24 hours. This required the Mir crew to make sure they took the time to read and delete mail messages daily to keep the mailbox open. For some crews the PMS was just too time consuming, and when the mailbox filled, the crew would just shutdown it down for days.

To help elevate the full PMS Mail box problem, MAREX-MG wanted to fly a modem with more memory (at least 128k) and possibly more options. Several manufactures are making amateur radio modems and the PacCom Company was our first choice. The PacCom Company has been very supportive of the Manned Amateur Satellite projects. Their modems have proven to be very reliable and have flow on both Mir and the Space Shuttle. Unfortunately PacCom did not have a high-memory modem available to meet our upcoming launch date. MAREX-MG began searching for a new modem and for funding of the replacement modem project. The launch date was getting closer, even though we wanted more features; we had to settle for an existing "Off-the-Shelf" version of a modem. There just was not enough development time in our launch schedule to make any major changes to the new modem. As a backup project, Dave Larsen hired an engineer to modify the software for the PacCom modem, in an attempt to make the PacCom modem work with 128k RAM.

After extensive searching, the Kantronics "KPC-9612 Plus" modem was chosen to be the new replacement modem on board Mir. This modem was already in production and supported 128k RAM. It also supported both 1200 and 9600 baud data rates. MAREX-MG made arrangements with CQVHF magazine to purchase two of the KPC-9612 Plus modems for evaluation purposes. To complete the whole project, I would need a total of 6 modems to meet all the needs of testing, training and System-Operator stations. The first two modems did not arrive until June 24^{th 1997}, and testing began immediately. The July 1^st deliver date to Moscow did not seem like a realistic date. We realized we would miss the delivery date for the July Progress 35 cargo rocket. The modem project was rescheduled for the December Progress 37 cargo rocket. I still needed 4 more modems to complete the project. With the change in schedules, it looked as if I would have time to get the extra modems and cables completed in time for the December launch. We’ll at least that’s what I thought.

Most of the testing was conducted in my home shack and in my companies RF Lab at night. The Kenwood Corporation had provided MAREX-MG with two identical Kenwood TM-733 Dual band radios. The TM-733 is the same radio, which is currently used on board the Russian Space Station Mir. It was important to test the modems in a configuration identical to what will be used on Mir. I built some temporary cables and connected each of the two modems to a Kenwood TM-733. The parameters of the KPC-9612 Plus were adjusted to match the specifications of the Kenwood. Additional adjustments were added based on my previous 6 years of experiences with Mir Packet operations. Both modem and radio configurations worked flawlessly in the lab. The next test was to place the modems 10 miles away and test for weak signal receptions. Jerry Muller, K0TV, volunteered to take one of the systems and set it up at his home. Over the next week extensive testing was performed to verify the modem's ability to detect weak data packets, in both 1200 and 9600-baud modes. The station at Jerry’s home was configured for 5 watts into an omni directional antenna. The station at my home was connected to a directional beam. By rotating my beam, I could cause the received signal from Jerry’s station to dip down into the noise level or up to S9. This gave me the opportunity to test a wide variety of signal and noise levels.

It is very important for the modem and radio under test to be able to detect weak packet signals. The Mir Space Station will only be in radio range of your home for a maximum of 10 minutes. When Mir first comes over the horizon, it is over 1500 miles away. The signals are usually very week at the beginning of a pass. The signals will vary from S0 to 10 over in just a few minutes. To conserve power, the Mir crew usually keeps the PMS radio set for the low power setting of 5 watts. The existing Personal Message System (PMS), combination on Mir has proven to be very reliable at this low power setting. The goal was to design the new modem system perform just as well. The new Kantronics KPC-9612 Plus worked very well with the Kenwood TM-733 in both 1200 and 9600 baud modes.

There were a few operational differences between the new modem that users of the existing system would have to get use to, but nothing serious enough to prevent the project from flying.

The modem combination seemed stable enough to send to Moscow for their evaluation. The new modem passed the Moscow MAREX teams evaluation and MAREX-MG was given permission to send the new replacement to Mir. Then out of the blue came a change in delivery schedules. Instead of the December Progress 37 cargo rocket, there was a possibility of sending the modem on the August Soyuze manned crew change rocket. There was a problem, I was still was not quite ready because of the hastily built power and data cables were not "Flight Quality." I need to build flight quality data and power cables over night and get this package on its way to Moscow by courier.

So I did what all engineers do in a pinch, I ran down to Radio Shack and stocked up on supplies. Working through the night building and testing cables, I was able to complete one full system by morning. I had run short of the DIN data connectors for the Kenwood radio and was not able to send Moscow both modems in one shipment. Flight rules' state, that there must always be a backup system at the launch pad, just in case the primary system stopped working. These rules also applied to Amateur Radio equipment, but I did have my fingers crossed. The Soyuze rocket launched on time with a new crew and supplies for American Astronaut Mike Foale. I had sent Mike a status report on the Modem project, and have asked him to look around for it.

Stat : PR

Posted : 08/08/97 11:50

To : WF1F

From : R0MIR

Subject: Modem

Miles, so far not seen the modem. They [the replacement crew Anatolry & Pasha] have very little stuff with them.

I will pass your greetings.

Mike.

After the August Soyuze launched, I was informed that the Kantroncis KPC-9612 Plus did not fly because I did not send two modems. Oh well, time to build the second cable set. The parts for the second modem finally arrived and I was able to get the second modem on its way by courier to Moscow. Because of the change in schedules, I did not have time to get the additional 4 modems for the training and System-operator stations. Everything I had was sent to Moscow, even the manuals. During negotiations with Moscow, the date for the modem launch kept changing. MAREX-MG was assigned a new launch date on the Progress 36 cargo rocket in October.

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

While all of this is going on, the Mir Space Station had its worst accident in its long successful 11-year history. The unmanned cargo rocket Progress 34 collided with the Spektr module on June 24. The accident caused the

Spektr module to depressurise and the crew had to seal-off and abandon that one module, but they still had access to the other 5 modules.

Message from Mike Foale to Dave Larsen

Posted : 06/26/97 18:50

To : N6CO

From : R0MIR

Subject: Back on line

Dave, looks like we are back in business - less one module.

Mike. kb5uac

 The Spektr module provided 60% of the Mir stations electrical power. Now the Mir station was critically short of power. To make matters worse, the Attitude Control computer for the space station was broken and would only run for a few days at a time before crashing. You many think that the priority of the Amateur Radio on Mir would drop to an all time low, but just the opposite happened. The Mir crew realized that the Mir Amateur Radio was one of the most important experiments on the Mir Space Station. The crew needed to be in constant contact with ground control. A constant communication link was not possible because of the almost constant tumbling of the Mir station and a temperamental commercial Satellite Relay link. The crew found them selves out of radio contact with Moscow Mission Control for several hours of the day. The official commercial Mir radio channels were booked solid during every VHF pass over a Mission Control ground station. The backlog of radio messages left very little time for family traffic over the commercial channels. The crew realized that MAREX-MG could help handle some of the family traffic. Dave Larsen began handling some of the personal Email traffic between the Mir crew and their families. And I was running phone patches between the Mir crew and their families in the UK and Moscow on a weekly basis. The success of the phone patches and the reliable E-mail service elevated the priority of the Mir amateur radio to the top. Even when the crew was floating around with Flash lights in their mouths and no heat, they still has enough power to dedicate to PMS experiment. (Amateur Radio saves the day again.)

Posted : 06/28/97 17:58

To : ALL

From : R0MIR

Subject: Mir Status

We have now got the base block, the module Kvant 2 back on line, leaving 2 more modules [unpowered].

Working very hard, lights in our mouths, in the dark, moving batteries about, to enable better charging, with solar arrays.

O2 electrolysis soon, in old Kvant.

Much interest from control center to do internal EVA to reconnect power to lost Spektr module, to receive

its substantial electrical power from its large arrays.

Thanks for all your good wishes. Mike.

Stat : PR

Posted : 06/29/97 09:50

To : WF1F

From : R0MIR

@ BBS :

BID :

Subject: batteries

Miles, we know about batteries dying.

Floating in a totally silent station, with 3 flashlight bulbs left, in darkness, with only the stars

to light you up, is pretty memorable. Bulbs in end pieces of mags [flashlights] used up.

Yesterday, I thought

I [had] lost High power transmit capability, because they [W5RRR] could not hear me.

When I switched [the Kenwood TM-733] to Medium power, they heard me. On High power I saw signal o dont know what to think.

Maybe coincidence. Anyway, am still on Medium power.

Mike. kb5uac.

(The power supply for the Kenwood radio was being over loaded. When Mike Transmitted on high power

the power supply would shut down. When the Spektr module was abandoned, the crew also lost a few of the DC-to-DC 28 volt to 12-volt converters. The SAFEX Amateur Radio power supply was now being used to run most of the Laptop computers and the Kenwood radio. Mike now had to be careful not to overload the 15-amp power supply.)

Posted : 07/02/97 14:00

To : ALL

From : R0MIR

Subject: Mir IVA/EVA

We are still in low power status, only one module and base block are powered presently.

Crew preparing to do EVA inside node, to open hatch of Spektr module, and replace with hatch

with special pass through’s, to allow power from Spektr.

Date TBD, but after 11th July. Progress docking planned for 8th.

Mike. kb5uac.

Posted : 07/07/97 09:40

To : ALL

From : R0MIR

Subject: Mir Progress Docking

Progress docked normally this morning. We are waiting 3 orbits before we start to unload it, checking the integrity of the hatch seals.

The station attitude control system is working well, using the girodynes, and the power sth the base block and module Kvant 2 powered (airlock and toilet) with modules Kristall and Priroda [are] unpowered.

Greenhouse experiment is continuing, using power from the base block, to

dry the seed pods that have formed quite nicely.

Mike. kb5uac

 Then one day I got a call from Michael Foale, he was having problems with the commercial packet link. Mike thought the modem was broken; I thought it could be just a parameter problem. It seems that when Moscow sent a large file up to Mir, the 20-kilobyte file would fail to load during the short 10-minute window. Mike sent me a complete list of the TNC parameters from the commercial radio station. I analyzed the parameters and found a few problems. I sent Mike a packet message and followed up with a voice explanation of the changes. To make the new parameters work correctly, the Moscow ground stations would need to make most of the changes. On the very next orbit, I head Mike calling Moscow and relay the information I had given him. Rather than change the parameters, Moscow decided to have the crew switch to a different modem, one with a known good working history. The Mir crew took the PacCom-2 modem off the PMS station and connected it to the commercial radio.

Stat : PR

Posted : 08/04/97 10:17

To : WF1F

From : R0MIR

Subject: TNC

Miles, TsUP has not asked us to test MFJ, since then.

Still using PacComs..

Mike.

All is not lost. We still had the PacCom-1 modem with the dead memory battery on board Mir. Mike Foale reconnected the old modem to the Kenwood and figured out how to load in all of the correct TNC parameters. The old modem worked well, except during the numerous power failures, which required a manual reload of all of the TNC settings.

Posted : 07/25/97 09:53

To : ALL

From : R0MIR

Subject: Mir status

Lost power to TNC again - lost all messages.

Possibly will get new TNC, with memory protection, in August, with next crew.

We are doing experiments, especially Vassily and Sasha, even though they now have

very little time Peiroda and Kristall still without power, but a little drier now, though still dark.

I planted the first ever space produced seeds, two days ago, in Greenhouse.

No sprouts yet.

Mike. kb5uac.

I sent an e-mail to Sergej Sambrouv the Chief of the Amateur Radio Cosmonaut department at Enegera in Moscow. I had requested to arrange a schedule in November 1997 to work with one of the crewmembers to install and verify the new Kantronics Modem. While we were discussing a schedule date, we had a minor setback. It seemed that during the November 5 space walk on Mir, the 2-meter PMS coax cable out side came loose. The 2-meter station has to be shut down until the next space walk in January 1998. I decided to wait until January and try again. The down side is that the PMS would be off the air for over 8 weeks. The SAFEX team came up with the idea of sharing the Tri-Band antenna mounted on the Prodia module for both the SAFEX-II 70cm Repeater and the 2-meter PMS. There is a Di-Plexor filter built into the SAFEX-II Repeater, which will pass 2-meter signals through the repeater to the outside antenna. In theory, both projects could share the same antenna at the same time. The Mir crew was given the information and then moved the 2-meter PMS station from the Mir-Core module into the Prodia module. During the move, the crew decided this would be a good time to install the new Kantronics KPC-9612 Plus modem. Of course the crew made all of these changes while I was away on a family vacation (with out my radio or computer). When I got home, I found several e-mails from hams that heard Astronaut David Wolf calling for me on 2-meters. I also had received a packet data dump from Mir indicating the Kantronics KPC-9612 Plus had been put on line.

07-Dec-97 18:12:58 CONNECTED to R0MIR-1

[KPC9612P-8.1-HM$]

96242 BYTES AVAILABLE

THERE ARE 12 MESSAGES NUMBERED 7-20

Welcome to the Mir Personal Mail System

ENTER COMMAND: B,J,K,L,R,S, or Help > L

MSG# ST SIZE TO FROM DATE SUBJECT

21 PN 166 ALL N6CO 12/08/97 05:15:58 2 Line MIR Keps 12/05

ENTER COMMAND: B,J,K,L,R,S, or Help >

The Mir crew found all of the required parts to get the to get the new modem connected, that’s the good news. The bad news was, that the crew had "Reset" the modem and erased all of the pre-configured TNC settings. The "Reset" rendered the modem almost useless. There were several commands, which needed to be set to correctly match the Mir environment. One of the parameters that needed to be fixed was the CD command (Carried Detect). This command had defaulted to the "Internal" Squelch control setting. The default parameter requires the crew to set the Squelch knob on the radio to the proper level to control the "busy" signal to the TNC. The crew normally keeps the Squelch and Volume controls set to the "OFF" position. As a result, the TNC always thought the channel was busy and would only send out random busts of packet data. The correct setting should have been an auto detect mode, in which the TNC monitors the audio stream specifically looking for packet tones to determine if the channel is busy.

This modem also has the ability to allow the System-operators to remotely change TNC parameters. The System-operators were planning to this feature to fine-tune the TNC parameters. Unfortunately when the modem was reset, the access codes were also erased.

Dave and I began to go through channels, with formal E-mail messages, phone calls and faxes to Sergej describing the TNC problem. Sergej then forward the messages to Mir over the official channels. Unfortunately the crew's workload during the December through February time frame was very high and the crew did not have much spare time to fiddle with the Amateur radio experiment.

On February 21, the Mir crew was able to reconfigure the basic TNC commands, which allowed MAREX-MG to access the KPC-9612 remotely and begin to fine tune the TNC settings. A few orbits later, MAREX-MG was uploading Message traffic reliably from VK land to Mir.

New Features of the KPC-9612 Plus

MAREX-MG hopes that some of the new features of the KPC-9612, will make it easier for the Sysops to support the Mir Personal Messages System. And at the same time, help reduce the amount of crew time required to maintain the mailbox. Another goal was to improve the overall reliability of connections and increase the number of users of the PMS during an orbit. Some of the options below, will help us with our goals.

1. Check Timer

The Check Timer, is like an Idle timer. If someone logs in to Mir and is unable to log out of the Mail Box, the adjustable Check Timer force a Log off. This is a new feature will help reduce the amount of time the mailbox is stuck waiting for an out-of-range station to respond. How many times have you seed the PMS fly by, and no one could log in because the connected station was out of range?

The old PMS did not support the ability to change this timer, as a result, it required 7 minutes to time out, when the connected station went out of range. The new PMS will force a log off after 60-120 seconds of inactivity.

2. Remote SysOp access

This option has already proven it value in the first few days of operation. At last the Sysops can now remotely fine-tune the TNC settings, without using any of the Mir crews time. The TNC settings used on Mir are not the same settings you would use for Terrestrial packet operations.

With the old PMS, if we needed to change any of the parameters, it always required the intervention of the Mir crew. To schedule crew time, required numerous expensive phone calls and faxes to Moscow. The crew time is very precious, and the Amateur Radio station should not be intrusive into their schedules.

3. More memory

The old modem had 13k of memory for Mail storage. The new modem has 100k of memory just for Mails messages. In hind site, I should have gone for the 512k version.

4. Software Adjustable Audio Levels.

With the new Kantronics KPC-9612 Plus, we have the ability via software to remotely adjust Packet Audio levels in the TNC. The Audio levels were set in the lab to be compatible with our Kenwood TM-733. The 733 on Mir may have slightly different audio charastics. This option will allow the Sysops to fine-tune the Packet down link audio level to the best possible level.

1200 verses 9600 baud.

The MAREX-MG team believes there should always be one or more satellite projects specifically designed to allow beginners world wide access to an "Easy-Sat." The Mir 1200-baud PMS 2-meter mono band project has proven to be the simplest and least expensive mode for beginners to use. The addition of a dual speed modem does not mean that 1200 baud PMS will be shutdown. There is now sufficient amateur radio equipment on board Mir to support two simultaneous mono-band projects. If the multi-radio configuration project is approved, it is possible to simultaneously support both 1200-baud packet on 2-meters for beginners and a 70 centimeter 9600 baud packet station for stations that want a greater challenge.

Next Projects:

Now it is on to the next project. The SAFEX engineers from Germany told MAREX-MG there was a problem with interference from one of the commercial transmitters desencing the 2-meter station. The MAREX-MG team contracted with the company Digital Communications Inc. (DCI) to custom build three special Pass-Band-Notch filters specifically for the Mir 2-meter PMS station. The first filter was built and displayed at the first Amateur Radio International Space Station conference at the Johnson Space Center, on November 1996. Due to red-tape and limited MAREX-MG funding, the filter is not scheduled to fly until early 1998.

The Slow Scan TV project may be more interesting to most people. The Mir SSTV project is still in the proposal stage, which means it is not an approved project. However MAREX-MG has gone ahead and built 4 prototypes systems for test and evaluation. If the projects gets approval, you may be able to hear and See the crews living in space via two-way SSTV.

The Modem Replacement project would have been much more difficult if it were not for the support of dozens of volunteers from around the world and from corporate sponsorship. The MAREX-MG team would like to thank all of the people and sponsors who have helped make the Mir Amateur radio projects a big success.

CQVHF Magazine

ICOM

Kantronics

Kenwood

KLM

SAREX Working Group

Thanks for all of your help, Mir has been and still is the most popular Amateur Radio satellite in the world.

Update April 3, 1999

The new MAREX-MG PMS has been more popular then expected and the users have been courteous and have learned most of the procedures for using the PMS. As a result of our training efforts the chances of uploading a successful message to Mir has increased. We have been analyzing the message counters of the PMS for the past year. The number show us that the Mir PMS is consistently receiving approximate 1000 messages a month.

For more information about MAREX-MG, please check out the MAREX web page at www.marexmg

Home