What Is Subspace Communication On Star Trek?

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Welcome to Trexpertisea series where we break down the technology, history, details, and decisions that make the Star Trek universe so complex — and so fun.

Working on a Starfleet vessel in the 24th century, one can safely assume that you have, essentially, the best wi-fi in the galaxy. A galaxy-class vessel like the USS Enterprise-D, for instance, is (naturally) crisscrossed with optical data networks, local subprocessors, and short-range RF pickups, which all, in turn, link to the various personal communication devices and PADDs (the iPad-like widgets on “Star Trek”) all over the ship. All of this information is culled from the handy-dandy “Star Trek: The Next Generation Technical Manual” by Rick Sternbach and Michael Okuda. Intraship communication, as you can see, is well taken care of.

But how does long-distance communication work on “Star Trek”? After all, a lot of time and attention has been given to the technology that can make starships travel at many times the speed of light (and /Film has analyzed which “Star Trek” ships might be the fastest). How do audio signals or data files travel from a deep-space vessel all the way to a starbase hundreds of lightyears away?

This is all handled by subspace communication, a phrase so common in “Star Trek” that even hardcore Trekkies don’t often think about how it works. “Subspace communiques” are flung from the Enterprise with liberal frequency on “Star Trek,” and we kind of all take for granted the fact that an audio message will reach its destination quickly, even faster than a starship traveling at warp-9. Sadly, not a lot of on-screen attention has been given to the notion of subspace communication, so we must turn to technical manuals to really unpack how it works.

(Subspace, we should note right away, is a totally made-up thing.)

The term “subspace” actually can allude to several real-life things, such as mathematical principles. In “Star Trek,” though, it refers to a fictional “extra” dimension of space that the citizens of “Star Trek” can access with relative ease. It co-exists with normal space, although some species only live in subspace (such as the creepy kidnapper aliens from the episode “Schisms”). Most importantly, it’s a dimension where the ordinary laws of physics don’t apply.

According to the “Technical Manual,” a subspace signal travels at the equivalent of warp 9.9997, which is sixty times faster than the fastest starships. If one wants to get their message across the quadrant in a hurry, shunt that puppy into subspace. Remember that no object or signal can travel faster than warp 10 on “Star Trek,” as that’s when an object reaches infinite velocity. But a subspace communication signal gets terribly close. This is how a captain can have a face-to-face video call with a very distant admiral without any delays. Subspace communication is what Zoom would look like if it actually worked.

The term “subspace” is a catch-all term that “Star Trek” writers like to use to cover any kind of fantastical technology or phenomenon they like to make up. There are subspace phenomena involving subspace compression, subspace rifts, subspace sinkholes, and astral eddies. Recall how vast distances are in space. It’s probably why “Star Trek” never leaves the Milky Way galaxy.

Sending a radio signal into subspace also ensures less degradation in the broadcast, and a signal can travel about 22.65 lightyears before needing to be boosted and pushed along again. The signal can be pushed along quite easily, however, as the galaxy in “Star Trek” is lousy with unmanned subspace radio relay platforms. Many have been distributed among the heavens by Starfleet, but many others are manufactured by local species belonging to the Federation. The relays can push signals to just about any other array in a vast network, and they are typically compatible with every alien communication technology. They are public property. The implication on “Star Trek” is that there are millions of these things all throughout space, but they’re so small, we don’t typically stop to look at them.

There are, however, also many manned communication relay stations as well, as seen in the “Next Generation” episode “Aquiel.” A few Starfleet officers need to stay on board these arrays to make sure they’re always in working order and handling the huge amounts of daily data effectively. Working on a subspace communication array, however, seems incredibly lonely and tedious — the “Star Trek” equivalent of working in a lighthouse.

According to the “Technical Manual,” 500 new relays are built every year. Starships also have beacons and other temporary relays they can lay down, in case they go into uncharted space and need to send signals out in a pinch.

More than anything, though, it’s safe to take subspace communication for granted. It’s one of those things on “Star Trek,” like gravity, that we simply accept works. If you’re wondering how they communicate and other science facts, just repeat to yourself, “It’s just a show. I should really just relax.”