HamTV transmitter launched to ISS

Front panel of the HamTV transmitter

Front panel of the HamTV transmitter

On Saturday, August 3 at 1948 UT the Japanese HTV-4 cargo vessel was successfully launched to the International Space Station (ISS). On-board were the HamTV transmitter and four CubeSats carrying amateur radio payloads.

PicoDragon CubeSat - Image credit VNSC

PicoDragon CubeSat – Image credit VNSC

The CubeSats will be deployed from the ISS by the JEM Small Satellite Orbital Deployer (J-SSOD) between October 2013 and March 2014, they are:
•    PicoDragon a 1U CubeSat developed by Vietnam National Satellite Center (VNSC), University of Tokyo and IHI aerospace. 437.250 MHz CW beacon and 437.365 MHz 1200 bps AFSK AX.25 telemetry.
•    ArduSat-1 developed by NanoSatisfi. 437.325 MHz 9k6 MSK CCSDS downlink.
•    ArduSat-X developed by NanoSatisfi. 437.345 MHz 9k6 MSK CCSDS downlink .
•    TechEdSat-3 developed by interns at the NASA Ames Research Center. 437.465 MHz 1200 bps packet radio beacon transmitting 1 watt to 1/4 wave monopole. It plans to test an Iridium Satphone modem and has a deployment mechanism to de-orbit in 10 days.

They are 1U in size (10*10*10 cm) except for TechEdSat-3 which is 3U (30*10*10 cm).

The company NanoRack has announced it is sending 36 Units of CubeSats to the ISS (believed to be 26 separate CubeSats, some 2U or 3U in size). At the time of writing it is believed they will be going on a later cargo vessel.

A basic amateur radio station that should be able to receive HamTV from ISS - Image AMSAT-Italia

A basic amateur radio station that should be able to receive HamTV from ISS – Image AMSAT-Italia

The HamTV transmitter is the culmination of over ten years work to establish an amateur radio TV transmitter on the ISS. It will use patch antennas fixed on the Meteorite Debris Panels (MDP) protecting the hull of the ISS Columbus module. These antennas were installed while Columbus was being constructed. A fund-raising campaign took place during 2005-7 to raise over 65,000 Euros for the antennas. Individual radio amateurs from around the world donated generously as did several organisations such as AMSAT-UK and the RSGB.

The transmitter will be installed in the Columbus module in the coming months. It can transmit DVB-S signals on 2422.0 MHz or 2437.0 MHz at either 1.3 Msps or 2.3 Msps with 10 watts of RF output.

The main mission of HamTV is to perform contacts between the astronauts on the ISS and school students, not only by voice as now, but also by unidirectional video from the ISS to the ground.

In addition to school contacts the equipment is capable of transmitting other pre-recorded video up to 24 hours a day to allow ground stations tuning.

HamVideo is the name of the onboard DATV S-band transmitter. HamTV is the name of the complete system, comprising DATV downlink and VHF voice uplink. Kaiser Italia SRL was the prime-contractor for the design and development of the flight and ground segment http://www.kayser.it/index.php/exploration-2/ham-tv

Read the HamTV overview paper at http://tinyurl.com/HamTVoverview

HamTV Link Budget http://www.amsat.it/Amsat-Italia_HamTV.pdf

HamTV on Facebook https://www.facebook.com/Hamtvproject

ARISS DATV Antennas Installed on Columbus http://www.ariss-eu.org/columbus.htm

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HTV-4 launch - Image credit JAXA