Look, there's no point in trying to act all cool: we're all pretty excited about the new Star Wars trailer. Our pals at iO9 did a great scene-by-scene breakdown of it, but I want to focus on just one bit of important hardware seen in the trailer — that fast little droid with the spherical body.

So, just to prepare everyone, this is going to get pretty damn geeky up in here, so put on whatever protective gear you may need to protect yourself. And know that I'm going to be writing about this from a perspective within the Star Wars universe, and in that universe there is a healthy and competitive market for droids, and I'll be pulling liberally from other canon and canon-ish Star Wars sources. Okay? Let's get all geeky up in here.


There are three things you'd probably notice first about this droid from the brief look we get: it has a spherical main body, its head appears similar to other R-series droids we've seen many, many times in the Star Wars universe, and it's a cute little fella. Let's focus on the first two things, starting with its status and place in the R-series lineup.

For those of you unaware, there's three main categorizations of robots/droids in the Star Wars universe: roughly humanoid-designed robots; short, barrel-bodied three-legged robots, and pretty much everything else. We're going to focus on the short, cylindrical ones now. These are generally known as astromech droids, and the famous R2-D2 is a member of this group.


Astromech droids are sort of general all-around repair droids. They seem to be used for just about everything, from maintenance to manufacturing to military use to starship navigation and even for serving drinks. They're rugged, highly customizable, and wildly useful. The most common of these droids is the R-series, made by Industrial Automation.

So far, there have been nine known types of R-series droid, and five of these have actually been seen in the movies so far; the others appear in other Star Wars-related media. Here's a quick little guide to what each of these series of droids looks like:

Of course, R2 is by far the best known, since R2-D2 is one. The next most well-known is probably the R5 series, since one of those was prominently featured in the original Star Wars movie when it had a bad motivator and blew up part of its head. R1s are huge and only seen in the background, R3s have a clear dome, and R4s have a more conical head.

The remaining four are mostly known to more hard-core fans: R6s have an R2 face on an R5-shaped head, R7s have a triangular eye, R8s have a little dish for a main eye, and R9s have a dome-shaped head with a little inset at the bottom.

Of course, there's more details about how they differ, but we're here to speculate on this new droid type. It's clearly related to the R-series, but there's one key difference: where all R-series droids have a cylindrical body, this one seems to be rocking a sphere.

I think this is a big enough difference to put it in a whole new series — lets call it an S-series droid, since that both comes after R and stands for "sphere." Let's really scrutinize this tiny video clip and see what we can learn.

First, let's go with what we know: that domed head. That's a classic R-series design, showing up in R2, R3, R7, R8, and R9 droids. The head isn't one we've seen before, though it does have a strange similarity to the original, strangely off-model R2-D2 action figure released in 1977 — I wonder if this was a deliberate reference?

The key parts are all there — the main radar eye, what's likely the hologram projector, various other status indicators and panels for equipment — but everything is a bit cleaner and more streamlined, lacking many of the bezels and complexity of, say, an R2. The main eye is a good bit bigger, which is likely what's triggering our neoteny-focused cute glands to secrete awwwratonin. Still, if this head was placed on a can-shaped body, I'd have called this an R10.

But, of course, it's not. It's on a spherical body. And we should try and figure out why. Luckily, I think I have an idea that makes a lot of sense.

If you look at the overall performance of the R-series droids, they seem to be pretty fantastic overall, but with one huge achilles' heel: mobility. The three-legged setup — two side legs, one retractable driving/steering leg of the R-series got the droids around, but not easily or quickly.

In almost any scene with R2-D2 in any of the movies, the little blue droid is almost always lagging behind. He's just not quick. And, getting through rough terrain or even a flight of stairs just makes an R-series droid even slower. Sure, the prequels showed that R2 had little add-on rocket thrusters to get around, but those weren't very useful in confined spaces, and they didn't seem very efficient. Or reliable, if we take their total lack of any mention in Episodes IV-VI as an indicator that they just didn't work anymore.

With this in mind, a spherical body that also served as the primary means of locomotion starts to make a lot of sense. A spherical 'wheel' has a lot of advantages: it's omnidirectional, can be controlled for very precise motions, encloses a decent amount of space for more hardware and is relatively simple, mechanically, at least when compared with having multiple separate driving legs and wheels and all that sort of thing.

The question now is exactly how does this setup work? I think there's basically two ways it could go, and the trailer doesn't really give us enough information to see which one it is at this point. The head and sphere are either connected via a central spinal shaft though a divided sphere acting as two hemispherical wheels, or the head and sphere have no physical connection, and rely on some sort of magnetic/sciencemagical connecting force and a wireless method of data and communication transfer.

The first method — a physical, mechanical connection has been referenced at least once in some concept art. This doesn't necessarily mean this is the way the droid actually is, but it does show thinking along these lines has happened. In a sketch re-creating the unseen concept art, the sphere actually divides into six parts, divided vertically to make a domed outer section and two roughly wheel-shaped sections per side. A central spinal shaft supports the head, and a horizontal axle joins the segments.

This is a probably solution, and could work well, but I'm not 100% sold on it, for a few reasons that could make sense to Industrial Automaton in the Star Wars universe. First, it's pretty mechanically complex: previous R-series droids sold so well because they were so durable, and part of that had to be because, while complex internally, their basic frames were simple, unfussy barrels.

And while this setup makes communication between head and body robust and easy, it does lose one of the big advantages of a spherical wheel: complete 360° steering. The setup shown here is essentially like a Segway or something — one axle with wheels. It can make tight turns and go forward and back, but it can't go side-to-side or all around like a spherical wheel could.

The other method would be one pretty new for an astromech droid, but seemingly well within the capabilities of Industrial Automation. It's a robot design idea probably best known in Eve, the life-form seeking robot from Pixar's WALL-E. Eve's head had no direct mechanical connection to her body, being attached via some sort of advanced energy system; it's possible that's what's going on with our S-series droid here.

Connecting the head to the body-sphere with non-physical forces would allow completely 360° motion of the body sphere/wheel, which would give incredible maneuverability. We've seen all sorts of objects with anti-gravity and force fields in the Star Wars universe — I don't see why this technology can't filter down to a mass-market droid.

Using an energy-based method of body/head attachment would be much simpler mechanically, allow for a much more robust spherical body casing, and, from a hypothetical owner's perspective, I think make routine maintenance much easier. Such a system is no doubt very energy hungry and sophisticated, and probably a little dangerous to work on in your garage. But I think the benefits outweigh the cons here.

Plus, I think the clip in the trailer looks a bit more like the energy-based system than the mechanical. There's no obvious force-field glow or anything (though, to be fair, Star Wars hardware tended not to go for that — look at Luke's landspeeder) but the sphere doesn't appear to be divided, no central 'neck' shaft is visible, and the head bounces up and down on the sphere as though it's not on a mechanical shaft. Though, that could be a head suspension system in action.

I'll be curious to see more of this plucky and quite fast-looking droid in the future. I think Industrial Automation has a real winner on their hands here, solving one of the longest-standing issues with the R-series, while keeping a tie to the lineage we all know so well.

I think I know what I'm going to be getting for my next astromech purchase! I'm sick of waiting for my old R6 to catch his ass up all the time when I'm at the hardware store.