All the interesting information is missing in this article. It’s like writing about technical details of the telephone network under the headline “Man Reaches President With Normal Telephone”. It’s not surprising that the White House has a telephone number, it’s surprising that the call was answered.
Reaching something that is merely a few hundred miles away with no obstacles blocking the signal doesn’t seem very challenging to me. The problem has to be the speed with which the ISS is moving across the sky which doesn’t give you very much time to make contact.
Much more interesting, however, would be why the hell the ISS is listening and responding.
Most astronauts are HAMs. Also, for an emergency radio, go calculate the signal strength of a 1W 2M/70cm radio with the worst possible antenna: damn near everybody can 'hear' you. Your signal can be heard clearly up to, I think, around 8000 miles. One of the older ARRL magazines published that as one of the 'games'.
There are other references available on that page.
Several of the ISS crew are licensed amateur radio operators, and they will be available on the air as their work schedule permits. Often contacts are scheduled with school classrooms, as noted http://www.arrl.org/ariss-contact-stories.
So part of the problem is the angular velocity of the station as seen from earth, but with omni-directional antennas on the ground, that is not a significant obstacle. The biggest obstacle is the work schedule of the crew.
As wglb points out, they frequently talk on their amateur radio as a means of entertainment. A lot of astronauts that go up to the ISS get licenses so they can chat with people when they get bored and have some free time on their hands.
Nope. HAM has its own spectrum that is unrelated to the station's primary communications radios, so keying your mic over and over or continuously transmitting just means you'd be disrupting HAM communication (not very nice).
As ugh pointed out, all the important communication uses satellite communication links that are likely digital. It is more difficult to disrupt digital communications than it is analog. You'd have to send out a signal that was specifically designed to disrupt their communications, which can be triangulated in a hurry. It wouldn't be log before a bunch of black Suburban were parked outside your transmitting location.
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[ 3.5 ms ] story [ 35.4 ms ] threadReaching something that is merely a few hundred miles away with no obstacles blocking the signal doesn’t seem very challenging to me. The problem has to be the speed with which the ISS is moving across the sky which doesn’t give you very much time to make contact.
Much more interesting, however, would be why the hell the ISS is listening and responding.
Most astronauts are HAMs. Also, for an emergency radio, go calculate the signal strength of a 1W 2M/70cm radio with the worst possible antenna: damn near everybody can 'hear' you. Your signal can be heard clearly up to, I think, around 8000 miles. One of the older ARRL magazines published that as one of the 'games'.
Here are some references that talk about the process in general: http://www.arrl.org/frequently-asked-questions
There are other references available on that page.
Several of the ISS crew are licensed amateur radio operators, and they will be available on the air as their work schedule permits. Often contacts are scheduled with school classrooms, as noted http://www.arrl.org/ariss-contact-stories.
So part of the problem is the angular velocity of the station as seen from earth, but with omni-directional antennas on the ground, that is not a significant obstacle. The biggest obstacle is the work schedule of the crew.
http://en.wikipedia.org/wiki/Tracking_and_Data_Relay_Satelli...
It seems all their important stuff is routed via satellites in geosynchronous orbit.
Also, FCC jurisdiction or not, it's probably within ITU jurisdiction.
As ugh pointed out, all the important communication uses satellite communication links that are likely digital. It is more difficult to disrupt digital communications than it is analog. You'd have to send out a signal that was specifically designed to disrupt their communications, which can be triangulated in a hurry. It wouldn't be log before a bunch of black Suburban were parked outside your transmitting location.