Tuesday, August 17, 2010

Space stations: it's all about altitude

T1A05: What is the FCC Part 97 definition of a space station?

  1. Any multi-stage satellite
  2. An Earth satellite that carries one of more amateur operators
  3. An amateur station located less than 25 km above the Earth's surface
  4. An amateur station located more than 50 km above the Earth's surface

The correct answer is D–An amateur station located more than 50 km above the Earth's surface.

(Authority: 97.3(a)(40))

Yet another question about radio regulatory jargon. The term "station" is, itself, specialized jargon in the radio services; despite the name, a "radio station" does not have to be stationary. A "space station" is, within the context of regulated radio (and thus amateur radio), simply a radio station in space. "Space" is defined as "anything more than 50 kilometers above the earth's surface".

The common notion of a space station typically requires that the station be manned; however, this thinking will again throw one off the radio definition. Space stations, in the radio sense, may be remotely operated or automatically controlled, just as any other station, and so a manned presence is not required. Nor is a space station required to be in earth orbit (although as far as I know there are presently no amateur space stations which are not in earth orbit). An especially high-flying balloon would count (although typically amateur radio ballooning activities tend to top out below the roughly 160,000 feet that defines "space"); so would a station on an object in solar orbit (such as, say, Mars) or even on a solar escape trajectory.

Amateur radio space stations have a lot of special rules that apply to them, but unless you plan on launching something into orbit you probably won't need to worry about them. The key to getting this question right on the exams is remembering two things: stations do not have to be manned, and anything over 50 kilometers is "space".

3 comments:

  1. The statement "at present there are no amateur space stations which are not in [earth] orbit" triggered my memory of the UNITEC-1 (now Shin'en) spacecraft that launched this past May. I read a call for amateur radio assistance in receiving the weak RF signal and tracking the spacecraft. Being a newbie ham, I asked around to see if I could find anyone planning to track it, but I didn't get any responses. If it's still on a nominal trajectory, would it count as a space station that's not in earth orbit?

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  2. Katie, that's a good question. While UNITEC-1 is, indeed, a space station that is not in earth orbit, it is probably not an amateur space station. The transmitter on UNITEC-1 does not appear to be licensed in the amateur space service. The frequency used, 5840 MHz, is in the middle of an international amateur satellite allocation but that band is coallocated internationally for nonamateur satellite uses, and is further also allocated in Japan (and most of Asia) to ordinary fixed and mobile use.

    I don't know much about Japanese regulatory process, but I imagine the transmitter on that satellite was approved by the Japanese government as a scientific apparatus and is authorized by Japan as a space-to-earth scientific satellite transmitter, rather than as a station in the amateur satellite service. However, this distinction is largely a matter of what paperwork was filed, and I simply have no access to that information.

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  3. Ah, thank you for that clarification!

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