Communications and Navigation

Given how tricky it is to pick up accidental radio signals — “leakage” — from extraterrestrial civilizations, how hard would it be to communicate with our own probes once they’ve reached a system like Alpha Centauri? A front-runner for interstellar communications is the laser. JPL’s James Lesh analyzed the problem in a 1996 paper, concluding [...]

As we move up the frequency ladder toward optical communications, each step takes us closer to the kind of data traffic we’ll need for deep space missions into the Kuiper Belt and beyond. The idea is to pack as much information as possible into the signal. A stream of data transmitted from an antenna spreads [...]

Why is it so tricky to deliver large amounts of data from space? One key issue is frequency — because the amount of data that can be transmitted varies with the square of the frequency, higher frequencies give you more bang for the buck. Moving the Deep Space Network from today’s X-Band (between 8.40 and [...]

One reason we need to re-think our communications strategies is that our resources are so limited. The Interplanetary Internet Project, for example, points out as a major justification for its work that if we can network spacecraft in distant planetary environments, we can sharply cut back on the amount of antenna time needed. After all, [...]