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Star Travel and You – Why It Probably Shouldn’t Look Like That

Star Wars is perhaps the most iconic mythology of the last century. Even if someone has never watched one of the movies, they know what a stormtrooper looks like. They can recognize a lightsaber. And moon-sized superweapons and the Force pervade every-day references. And yet, despite the impact of this great science-fiction epic, Star Wars has made a lot of mistakes in the “science” part of “science fiction”.

In fact, many of the trappings that we know and love are more for visual effect rather than practicality. And this is not limited to the generic details of the world, but the entire way that we perceive the culture of Star Wars functioning.

Some parts are far more obvious than others. Any Star Wars fan is used to great armies traversing the galaxy on a whim, fighting battles on planets halfway across the galaxy from each other in the same week, or even the same day. And yet, real space travel is prohibitively expensive. Like any technology, the price will eventually become more affordable the more advanced a society becomes, but that barrier will never be totally removed.

Even if we accept for a minute that these inescapable barriers have been overcome in some way that has yet to be discovered in our own societies, the materials that pervade the Star Wars galaxy aren’t particularly accurate either.

Quick, picture a star cruiser!

You probably came up with this:

ImpStarDestroyer-SWI125

The Star Destroyer is ingrained in popular imagination because of its awe-inspiring look. Heck, I have it as my screensaver. The powerful arrowhead design, with protruding command tower, covered with weapon emplacements. This truly is the battleship of the future.

Of course, anyone who has much knowledge of the modern navy will tell you that a real warship looks nothing like the ones that we think of from fifty years ago. And just like that change has occurred, realistic ships of the future will unfortunately look nothing like the Star Destroyer.

Reason 1: Stayin’ alive, stayin’ alive

A Star Destroyer’s design isn’t all that different from the Space Shuttle that we used the last few decades, but there is a big difference in the power generated by the two ships. Spacecraft of Earth rely on chemical reactions to provide propulsion and generate electricity for the few hours or days that they will be in orbit. And longer-term habitats like the International Space Station use well over half their surface area to collect solar energy.

When transporting anything sizeable between worlds, neither of these are an option. We’ve been able to get away with these methods for smaller probes to Mars or the now extra-solar Voyager missions, but they relied heavily on the use of gravitational slingshoting to manage this. And even with that advantage it would take them centuries to reach the closest system, making these completely impractical power choices for the future of space travel.

Another concept that actually exists that has appeared in Star Wars is the solar sail, as used by Count Dooku. We actually have the ability to make these now if we wanted to. But they rely on a large surface area of material to catch the solar wind – a stream of charged subatomic particles released by the sun (or any star) due to its own nuclear reactions.

However, the farther one proceeds from a star, the weaker the solar wind becomes as it is spread out in space. And even in the inner solar system, where the force is the strongest, a truly gigantic amount of material for the sail is required to catch enough of the solar wind to be of appreciable benefit for moving a payload. Additionally, the wind only goes in one direction – away from the star, making it only helpful for transport out of a solar system. Very. Very. Slowly.

So, what is the power source of future starships? Most likely a form of nuclear reactor. Without getting into painful specifics, there are a couple things that all types have in common: they require relatively little fuel to produce gigantic quantities of energy, and they give off a lot of harmful radiation that can cause fatal diseases in those exposed.

In fact, an analogue to these does exist in Star Wars in the hypermatter reactors that are mentioned as powering most ships. There has never been extensive detailing of how these reactors work, but the principle would not be particularly different. Essentially, anyone in a ship with one of these reactors would likely die or be hospitalized on arrival at their destination due to radiation exposure if they were anywhere near the reactor.

Seems like the death knell of space travel? Wrong. Two great forms of insulation from this radiation exist – lead, and distance.

Starships of the future will have a section with a reactor, and another far forward from this reactor and the associated engines, the crew quarters where people live. The two sections would be connected only by thin struts to allow passage for repairs, and the required electronics to pass between the two.

Lead lining of the reactor and facing side of the crew quarters would absorb significant amounts of radiation. And the amount of radiation reaching the crew quarters would be dispersed proportionally with the distance from the engines.

This design would allow the crew to stay alive while providing the power required to move the ship and supply the needs of the crew for the period of their transit.

Therefore, the most realistic ship in all of Star Wars that meets the criteria for being able to travel between worlds without killing its own crew:

NebulonBfrigate-TCWBRBD2

Reason 2: Yo’ momma so fat…

A few months ago we saw an astronaut strumming a guitar on the International Space Station. A copy of the Serenity DVD collection has made it up there, and there’s probably a couple action figures tucked in a crevasse somewhere. People like to take little pieces of home with them when they go somewhere, but if you ask anyone who’s gone into space, they’ll tell you that there’s an extremely strict limit not only on what they can bring, but how much it can weigh. Why? Because they need to calculate how much fuel they will need to be able to lift the load. Which in turn weighs more, requiring more fuel, which in turn…

You get the idea.

Gravity is like an overly-attached lover. It does not want you to escape. And if you do, you will be paying for it. And yet, Star Wars routinely depicts ships, even star cruisers landing on the surface of a planet and taking off like it’s no big deal.

paradeground

That’s not very practical at all. Most of the weight that those cruisers would be lifting is not in fact the men and supplies that they’re carrying, but their own weight in metal, reactor, fuel, and other ancillary parts. This would eat up unimaginable amounts of fuel that could otherwise be used to move between planets. Reducing both cost, and weight for the journey.

But then how does one get to one of these orbital ships?

There’s really two workable options. First, is something called a space elevator. Starting at some point on a planetary equator, a satellite is placed in geosynchronous orbit. Between the two stretches a looped cable. One end going up to the orbiting satellite, one going down to the surface of the planet. By ensuring that the satellite at the far end of the tether is heavy enough to maintain its orbit even when there is weight on the cable, loads can be hoisted into orbit and lowered back down to the surface of the planet with relatively minimal effort.

In fact, the energy output required for this if the ascending and descending loads are balanced is a fraction of what is required for the propulsion liftoff of a starship.

That gets you into orbit. But the mere fact that the satellite at the end has to be heavy and receive these ascending and descending packages means that there is only really one practical thing to build at the other end – a space station.

On this station, there would naturally be space for people and cargo that have just come up, and that are waiting to go down. The addition of airlocks around the rim of the station would allow interstellar ships to dock and release their cargo and passengers to the planet, while they were being resupplied essentially simultaneously with far less fuel expenditure.

Of course, this solution works only on developed planets that have the population and resources to build one.

The second option is to reduce the landing and takeoff weight for the ships that will have to fight gravity. This entails building a much smaller, lighter ship which can dock to a larger interstellar cruiser while still being aerodynamic enough to survive a landing to the surface of the planet, and have enough power to reach orbit.

In this case, size must be minimized, so nuclear reactors are out of the question and the ship will revert to using chemical reaction for propulsion on liftoff. These engines must be strong enough to overcome gravity without tearing the ship apart which means they will take up a significant portion of the volume of the ship. Therefore, cargo or passengers will be crammed into the smallest amount of space possible. The conditions would be far from comfortable.

Cargo and passengers would likely require different ships for this transport. Cargo does not require atmospheric regulation, so environmental controls can be removed from anywhere other than a small cockpit, allowing a heavier weight of cargo to be carried. By contrast, passenger transports would require both atmospheric control, and some measure of comfort for the passengers to prevent from injury during acceleration. This would allow some reduction of weight because people will never be packed as tightly as cargo, meaning that a smaller ship would be required.

Both, though, would require a significant degree of aerodynamics in order to not be torn apart during ascent and descent. This would involve a central payload body which contained the engines and some amount of wings to aid in lift or drag.

Therefore, the most realistic ship in all of Star Wars that meets the criteria for being able to land on a planet without ridiculous fuel expenditures:

Trade_Federation_Invasion

Reason 3: Bump and grind

If you want to go into space, you’d better not be claustrophobic. Remember how little space you have in economy class on an airplane? And how they’re trying to fit the seats even closer together now? Good. Now reduce your space a little bit more. You’d better like your seatmates. You may wind up knowing each other quite intimately.

death-star-hall
Approximate capacity: 923

Whether the acceleration is continued until halfway into the trip and the ship then begins to decelerate at the same speed, or whether acceleration is only continued until a specific velocity is reached is not terribly important. At the end of the trip the ship still needs to be slowed to a stop, and the greater the velocity of the ship the more acceleration (in the opposite direction) is required to stop it.

That of course requires fuel.

Therefore, there are two things that can be reduced in order to reduce the amount of fuel required: acceleration or mass. If we reduce the acceleration required, the trip will be a lot slower. And there’s a certain threshold at which reducing this therefore becomes completely impractical. But there’s also the ability to reduce the mass of the ship.

Everything has mass. Even the air you breathe. To move X amount of passengers and Y amount of cargo, you wind up moving X + Y mass inside the ship. Add the mass of the ship itself (let us call it Z) and you can figure out the total mass that needs to be accelerated.

Given that X and Y cannot really be reduced, unless of course you want to be the first space murderer, and that’s cool too, you are forced to reduce Z.

Well on the ship, you can’t really get rid of the hull, or the engines, or the fuel, or the reactor. So what can you get rid of? Well, pretty much any non-essential; Pools, private cabins, beds, art, trees, even the air that the passengers breathe (up to a point).

In a starship, every concession must be made in order for the trip to be practical. Cargo can of course be packed together in the most efficient way. Therefore, each passenger will have to sacrifice to enjoy the privilege of interstellar travel. Private cabins will not exist, nor will any recreational facilities. The fittings for these would add to the ship’s mass, as would the atmosphere required to make those sections of the ship inhabitable.

Similarly, facilities like washrooms (or refreshers) would be in limited supply, and communal. There would likely be only one kitchen, medical bay, etc. And privacy would be a thing of the past.

Therefore, the most realistic depiction in all of Star Wars that shows what space travel would really be like:

anakin-and-padme
First class accommodations at that!

Of course, there’s still the matters of artificial gravity, or sound in space, or inter-species atmospheric requirements that are glossed over in the Star Wars universe but would provide significant challenges in a real universe. However, we can assume that sounds are simulated by speakers in the ship for the benefit of the crew, someone figured out how gravity actually works and made it, and everyone somehow breathes the same stuff.

But even then, the vessels responsible for space travel as we so often picture them are very different than the reality of a civilization like we see in Star Wars. The movies and Expanded Universe give us a beautiful view of a fantasy world of elegant space travel. But unfortunately it is only that.

3 thoughts to “Star Travel and You – Why It Probably Shouldn’t Look Like That”

  1. Vikings in their long boats would have said that something like a Carnival Cruise ship could never, ever exist.

    … hmmm. They might have been right. Maybe that’s a bad example.

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