May 6, 2014
Ham Video Makes Its Debut On The International Space Station
[ Watch the Video: Ham Video Premieres On Space Station ]
redOrbit Staff & Wire Reports - Your Universe Online
For the past 14 years, people on Earth have been able to communicate with the ISS crew using standard radio equipment, the ESA said. The DATV system was developed by Kayser Italia and arrived at the station last August on board Japan’s space freighter. It was then connected to an existing S-band antenna in the Columbus laboratory.
The video signal works like standard TV broadcasts in that the crew members will not be able to see their audience, but they will be able to hear their questions and comments over the regular amateur radio system. The sessions have to be brief, as the connection requires a direct line of sight. Since the ISS travels at speeds of more than 17,000 mph, it quickly passes through the field of view of Earth-based amateur stations, the agency said.
The crew finished commissioning the set-up for the device on April 12, and NASA astronaut Mike Hopkins was the first member to broadcast over what has been dubbed Ham TV. He took part in a video chat with ground stations in Livorno, Casale Monferrato and Matera, Italy.
The ESA explained that they have contributed five ground antennas and equipment to the Amateur Radio on the International Space Station (ARISS) organization, which can be easily transported and repositioned as needed in order to receive video from the ISS when it flies overhead. When linked together, the agency said that the station is capable of providing up to 20 minutes of contact at any given time.
According to ARISS, the Ham Video transmitted operates with a Canon XF-305 camera. It has download frequencies of 2.422 GHz and 2.437 GHz, contingency frequencies of 2.369 GHz and 2.395 GHz, and a DVB-S like signal. Other characteristics include a DVB-S like signal (without PMT tables), symbol rates of 1.3 Ms/s, 2.0 Ms/s, FEC of 1/2, video PID of 256, audio PID 257 and RF radiated power (approximately 10 W EIRP).
“Ham TV will add to ham radio for space educational purposes, offering schoolchildren the chance to talk and see astronauts in space with simple equipment,” the ESA said. “Anybody can still hail the Station via radio and, if an astronaut floats by the always-on receiver, they might just pick up and answer the call.”