Hundred twelfth edition of the N&O column / Spooks newsletter

(Date: December 2006)

Voice stations | Morse stations | Various modes
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Space communications < 500 MHz

A number of new satellites have been launched in December. The Space Shuttle completed another mission to the ISS. The spacecraft was heard by quite a lot of people on 259.700 MHz.

Below is a short overview and the frequencies of the new satellites. I also included transcripts of messages that were heard during the past couple of weeks. The general info was partly taken from the respective websites. Check these for more information.

GENESAT-1

NASA's GeneSat-1 satellite was aboard an Air Force rocket and has been launched into Earth orbit on Dec. 11, 2006. The small satellite will carry bacteria that researchers will analyze to determine the effects of space flight on microscopic living things.

Operating at 437.075 MHz FM, the GeneSat-1 beacon sends an AX.25 packet every 5 seconds; the packet contains data about the spacecraft systems operation. The data portion of the AX.25 packet is 64 bytes long and contains only standard ASCII characters. Each character represents a HEX value. Below is an example of the 64-byte long raw data:

GeneSat1.org46CD00000000000000000024006A009F0000000000C600000000

Depending on the TNC being use, the data string could be preceded by the following set of characters: KE7EGC>UNDEF,TELEM: which denotes sender and recipient of the packet. Ignore this when decoding the packet.

Sample:

ANDE and RAFT and MARScom all contain systems involving US Naval Academy Student Projects. RAFT and MARScom are complete student spacecraft and the ANDE comm system was a student project. The 4th satellite, FCAL, was built at NRL but also contains an amateur radio cubesat for its comms and telemetry. These four satellites, all operating in the Amateur Satellite Service were carried to orbit on the Space Shuttle mission STS-116 at 8:47 PM on 9 December 2006. These missions will be short due to their low altitude.

ANDE

ANDE stands for Atmospheric Neutral Drag Experiment and is a 19" passive sphere with optical corner reflectors and 6 Lasers for precise orbit determination. The Naval Academy has been given the opportunity to construct a digital communications transponder for use in the Amateur Satellite Service to fit inside the ANDE sphere similar to what it is flying on the PCsat and PCSAT2 missions. The PCsat-like follow-on packet communications mission will continue the interest of students worldwide by letting them communicate via the satellite and capture telemetry relative to its temperature in the space environment.

Downlink mode: 1200 baud AX.25 TNC on 145.825 MHz.

Sample:

RAFT

RAFT is a US Naval Academy Aerospace student satellite project designed to give students real hands on experience in satellite engineering, design and operations. The USNA RAFT will accomplish these objectives:

RAFT PSK-31 Multi-user digital transponder

This transponder solves the primary problem of many amateur satellites and that is the contention on the single channel uplink. By using PSK-31, as many as 30 simultaneous users can be supported in keyboard-to-keyboard communications. Each channel is only about 60 Hz wide.

Downlink mode: 1200 baud AX.25 TNC on 145.825 MHz.

Sample:

MARScom Satellite

The MARSCOM picosat was carried to orbit on STS-116 on 9 Dec 2006 and was activated on deployment from the shuttle at 0156z on 21 December. MARScom is one of two Naval Academy small cubesats in a two-satellite constellation as part of the RAFT project.

MARScom Mission: The mission of MARScom is to explore and demonstrate a very low cost yet viable communications capability for education and training of both Midshipmen and the large numbers of Navy Marine Corps communications cadre personnel.

Since MARScom will be hard to track and tune due to the high Doppler on the 27965.2 LSB downlink, stations will need to ping the spacecraft to hear a downlink for tuning. For this reason, the initial operations plan for MARScom is simply to have ground stations hone their downlink tuning skills by transmitting occasional packets on the 148.975 FM uplink. While also attempting to tune in and capture any telemetry packets as well as their successful packets.

Here are the settings for your TNC:

DA YYYYMMDDHHMMSS <== to set your TNC clock
UNPROTO VIA NMARS <== to set your path via MARScom (NMARS)
MSTAMP ON    
CONV    

With these settings, you should be able to send a packet via NMARS each time you hit the CARRIAGE-RETURN key. Send any captured packets to the NMARS Telemetry coordinator.

The downlink will be available to all MARS stations, and the uplink will be operated as a directed net amongst authorized MARS command stations.

Downlink mode: HF LSB, 1200 baud packet on 27965.2 kHz LSB.

FCAL

FCAL, the Fence Calibration satellite. Its name is derived from its intended use as a calibration target for the radar fence, a space surveillance system recently transitioned from the Naval Network and Space Operations Command to the Air Force 20th Space Control Squadron. The size requirement of FCal satellite was determined by the resonant frequency of the Navy radar fence.

The two hemispheres are fabricated by spin-casting brass, followed by machine finishing. The exterior of each hemisphere is nickel coated for durability in the harsh space environment. The equator consists of an anodized aluminum deck that incorporates an antennae deployment system, and mounting locations for the FCal payload. A cubesat ballast mass is included for center of gravity symmetry.

Downlink mode: AX.25 AFSk 1200 baud on 437.385 MHz. Callsign: KD4HBO.

Sample:

MEPSI and TACSAT-2 were also launched. So far I haven't been able to find the frequencies and modes. It is said that MEPSI's beacon transmits on 150.012 and 400.032 MHz. I have tried these frequencies during several passes but nothing was heard.


Voice stations | Morse stations | Various modes
Military stations | Utility round-up | Clandestine activity survey
Satellite logs | Logs
Index | NS NL Home

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