The International Space Station orbits more than 200 miles above the Earth, traveling five miles per second. Getting in touch isn’t quite as simple as placing a long-distance call. But if you have a ham radio, used by radio amateurs to chat on public frequencies, it actually isn’t much tougher.
Last week, Adrian Lane of Gloucestershire, England, proved the point when he contacted the station and chatted with a US astronaut for about 45 seconds. The astronauts, it just so happens, have their own ham radio, which works like any other down here on Earth. Getting through to them is mostly a matter of knowing how and when to try.
To start, you need a radio (pdf), but before you run off to order one you should know that depending on your country, there are different licenses you may need to transmit on it. In England, for example, it’s fine to listen in without a license, but sending radio messages requires first passing an exam. In the US, three different license classes exist.
If you’re already set up, the next step is to know which frequencies to use. A handy guide is available through ARISS.org. The acronym stands for Amateur Radio on the International Space Station, and the organization is made up of a collection of space agencies and amateur radio groups.
Next is timing. Your best odds of making contact, according to Gizmodo, are when the station is directly overhead. NASA allows you to easily determine when the space station will be in your location, or you can try this pass predictor from AMSAT.
Astronauts are humans, of course, so they have schedules. ARISS points out that they’re generally awake between 7:30 UTC and 19:30 UTC—that stands for Universal time—and they’re most often available about one hour after waking and before sleeping. You can convert UTC to your local timezone with this tool.
That’s all the information you need to reach out. Of course, someone up there has to be listening, and as the New York Times points out, not all astronauts have a ham radio license. And just think, any Earthling that makes contact would technically be speaking with extraterrestrial life.