Ham video debut on the ISS

While amateur radio enthusiasts have been able to communicate with astronauts on the International Space Station since its inauguration in 2000, a new digital amateur television (DATV) transmitter installed in the Columbus laboratory will add a visual element to those conversations, the European Space Agency announced on Monday.

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.”

ISS dumps Windows into the vacuum of space

Laptop computers essential to the day-to-day operations of the International Space Station (ISS) crew will be switching operating systems from Windows XP to Linux, according to published reports.

ISS
The laptops, which are on the space station’s “opsLAN” network, are used by astronauts to interface with onboard cameras and complete several other routine tasks, Joel Gunter of The Telegraph explained on Friday. While Linux had already been used to run several systems on board the ISS, this means it will now be the exclusive OS used onboard the orbiting laboratory, he added.

“We migrated key functions from Windows to Linux because we needed an operating system that was stable and reliable – one that would give us in-house control. So if we needed to patch, adjust or adapt, we could,” Keith Chuvala of the United Space Alliance, the organization that operates opsLAN for NASA, told Gunter.

Getting rid of viruses
Dropping Windows in favor of the Unix-like, open-source operating system is “probably a good idea,” according to Jamie Condliffe of Gizmodo.

“Back in 2008, a Russian cosmonaut managed to take a laptop to the ISS that spread the W32.Gammima.AG worm to all the other laptops aboard the station. Using Linux would make that impossible,” Condliffe said. “The only hitch might be switching all the current, Windows-based software – for everything from viewing stock inventory to carrying out experiments – to Linux.

Let’s hope they don’t use WINE.

(via redOrbit)

Propagation on Mars

So we’re sending some people to Mars, who will surely die there. While I’m not really convinced that this endeavor will ever take place, it made me wonder:

  • How will radio radio signals propagate on Mars? Are there layers in the ionosphere (if there is such a thing there) which will allow signals to travel beyond line of sight?
  • If ham radio operators go, we need a new prefix. Anything in mind?
  • Do we need a ‘Mars band plan’?
  • Should we install repeaters on Deimos and Phobos?
  • Anything else important we should think of in advance?

mars

Please let me know what your thoughts are, and if you’re planning to apply for the trip – I’m always willing to arrange a sked.

Suddenly your QRP station looks pathetic

The two Voyage spacecraft have had an amazing track record. They were sent to photograph planets like Jupiter, Saturn and Neptune and have just kept on going past the outer edge of the solar system. Voyager 1 is currently over 7 billion miles (about 11 billion kilometers) away from Earth and is still transmitting — it takes about 10 hours for the signal to travel from the spacecraft to Earth.

voyager1

The Voyager spacecrafts use 23-Watt radios. This is more than the 3 Watts a typical cell phone uses, but in the grand scheme of things it is still a low-power transmitter. Big radio stations on Earth transmit at tens of thousands of Watts and they still fade out fairly quickly. Seven billion miles away, 23 Watts output – this equals to 304.347.826 miles per Watt…. beat that!