My Favourite Modes of Interstellar Travel

I apologise for the lack of reviews, and for the lack of content in general. I’ve been reading a lot of shorter fiction lately, and if I stopped to write a review after every story I wouldn’t have any time to read. I’ve also been working on a novel, which has been taking up most of my attention. I’ll probably talk more about that later in the month. I’ve also failed miserably at raising my tadpole, but the less said about that the better. 😦


For now, let’s just sit back and talk about the trope that makes a lot of our favourite science fiction possible. Yes, I am talking about that impossible piece of technology that is used in all the space operas, and that gets a pass in harder science stories despite rarely being explained.

I’m talking about faster than light travel.

Faster than light travel, and the interplanetary community that would form as a result. Think Space Opera of the grandest scale. Luke Skywalker flying from Hoth to Dagobah with little preparation and only R2D2 as crew. At the moment, that’s pure fantasy. In fact, it is quite possible that FTL travel is impossible, and I’ll make that assumption for the rest of the article. However, this dream is more about the interstellar civilization than actually travelling really fast. If we don’t destroy ourselves, settlements outside the solar system could be possible.

The Kepler telescope has identified thousands of exoplants, a handful of which could be capable of supporting life. One of these planets is Kepler-452b, which has been dubbed ‘Earth 2.0’ and ‘Earth’s bigger, older cousin’. Kepler-452b is so far the most Earthlike planet we’ve found, but unfortunately it is 1,400 light years away.

In August 2016, NASA found a planet orbiting our closest stellar neighbour, Proxima Centauri. The discovery of this planet – dubbed Proxima Centauri b – has caused a lot of excitement, since it is in the habitable zone of its star and there is speculation it could be an ocean planet. However, it’s too early to get our hopes on this planet yet. Proxima Centauri is a red dwarf star, and P.C b orbits it every 11 days. Such planets are usually tidally locked, presenting the same face to their sun all the time. We just don’t know if life could thrive on such planets. There are also worries that the planet might not have a strong enough magnetic field to prevent its atmosphere from being blown away. There are a number of other problems, but also a lot of uncertainty. Hey, maybe it is a cosy ocean world we can settle on. Don’t get sad if it isn’t though; the fact that there are planets nearby, and very Earthlike planets out there is encouraging. Though even if we find a new Earth, we still have to get there.

This is where organisations like 100 Year Starship come in. 100YSS is dedicated to making Human Interstellar travel a reality within the next 100 years. They partner with a range of researchers and groups to tackle the problems of such travel, everything from propulsion systems to maintaining bone density in low gravity. Elon Musk has also announced a plan to colonise Mars, and NASA has recently been given the task of getting Humans on the red planet.

It seems that we’re on our way to reaching the stars. But it’s going to take a long time until we’ve spread across the galaxy, and without being able to travel faster than light, visiting other planets in our interstellar civilisation won’t be feasible. For the small minority of people that do leave their home planet, it’ll be a one-way trip. Depending on the method of travel, it may even take up most of the passenger’s life.

Common ways people travel between the stars in science fiction without FTL travel include on slow generation ships (As in Universe by Robert Heinlein or Aurora by Kim Stanley Robinson), on ships travelling fast enough to be effected by time dilation (Tau Zero by Poul Anderson, The Ender’s Game series by Orson Scott Card), through some sort of gates/wormholes (the Honor Harrington series by David Weber), and in suspended animation (2001: A Space Odyssey by Arthur C. Clarke, Lost in Space). All three options are theoretically possible, and are being researched. They also make really good stories; I bet you can think of many more examples of each technology apart from the ones I listed.

But standard use of these technologies doesn’t appeal to me. I want to be able to casually go and visit another planet like they do on Star Trek; none of these technologies make interstellar travel convenient enough for me. A generation ship? That’s out for pretty self-explanatory reasons. Time Dilation? Well yes, I could visit many planets that way, but if time goes by faster for those I leave behind, that would hardly make such a trip an everyday thing. Very few people would travel this way, since by the time they returned home everyone they ever knew or loved would be dead. Wormholes would also be impractical, since we’d only be able to travel where the wormholes are. So, probably a pretty long ride on a spaceship to the gate. And suspended animation? Would have the same problems as time dilation in terms of everyone outside the ship ageing, but also it seems like a pretty extreme and risky medical procedure. There just isn’t any way travelling on a space ship in suspended animation could be a common-place, casual way to travel.

Or is it?lockstep2

Let’s talk about Lockstep, by Karl Schroeder. I read this novel as it was serialised in Analog, and each month I eagerly awaited the next instalment. The story is about Toby McGonigal, a seventeen-year-old settler in the Kuiper Belt who goes out in a ship with suspended animation beds and gets lost in space for 14,000 years.

He wakes up to a galactic civilization that has found a way to make travel over great distances possible and relatively simple using suspended animation technology. In this setting, if you jump on a spaceship and go to sleep for the thirty years or so it takes to get to the next planet, then your friends and family will still be there when you get back. How? Because in this empire, everyone goes into a state of suspended animation at the same time.

So here’s how it works. Everyone wakes up from suspended animation at the same time. You go about living your lives like normal for the next month, and then at the end of the month everyone goes back under for thirty years. Then wake up again, feeling like it has just been overnight, and repeat. This has numerous benefits to the population of this empire, since most planets in the story are small and have limited resources. While the population sleeps, robots can manage the world, replenishing the food and energy resources the Humans will need for their next waking month.

The other advantage, and the one most interesting to us, is that when different planets co-ordinate their sleep cycles, travel between them takes just a couple of months for everyone involved. If you want to go to another planet, then at the end of the month you just hop on a ship, and go to sleep. Everyone at home and at your destination will be asleep while you are. Let’s say it takes twenty years to get to your destination; then once you get there you remain in suspended animation orbiting the planet until everyone else wakes up. It’ll feel to you – and everyone else – like an overnight trip. Then you do what you came to do, and at the end of the month you get back on your ship and go home (or go on to another planet). A forty-year journey, and to everyone involved it seems like you have been gone only a month.

There are a few complications with this system. The first is getting everyone to agree on the same sleep schedule. In Lockstep, not every planet is on the same schedule. And even on the same planet, you may have communities with different schedules. Depending on how long you sleep for, you could travel the galaxy but never get a chance to meet your neighbours. There’s also the matter that this empire is ruled by a tyrant… but if we were to ever implement the Lockstep system in real life, hopefully we could do better.

So, by using suspended animation and a Lockstep system, we could get an interconnected Interstellar civilisation where the average person could travel between the stars. If we can agree on a sleep schedule. And if the technology is actually possible.

There have been some reports of humans experiencing a state similar to hibernation, such as that of Anna Bagenholm. There have also been promising results in experiments done at the University of Pittsburgh, where in 2000 they were able to put pigs in suspended animation and revive them by draining the blood and replacing it with a low temperature solution. Apparently, they were ‘mostly free’ of brain damage. In 2014 surgeons received permission to begin trialling this procedure on humans with fatal gunshot or knife wounds. A year later, I haven’t been able to find any information of how that’s going. Even if the trial succeeds, we must keep in mind that the technique is only designed to keep patients suspended for a few hours while their wounds are treated. Keeping a person under for years at a time is still a long way off. Still more likely to happen than FTL travel, but not for a long time.

So, Schroeder’s Lockstep system is one possible way for us to have a civilization capable of hosting real life space operas. But you know what? I’m pretty lazy sometimes. Like, really lazy. Can you imagine all the arrangements that would be needed for an interstellar trip with this technology? You’d need to buy a ticket, arrange a months’ worth of accommodation on the destination planet, which should be totally fun given how long it’ll take information to get there and back. Probably be insurance stuff to sign as well. Surely there has to be an even easier way to travel in an interconnected interstellar civilization?

What about teleporters? Well, I think before we even consider the technology there, we need to figure out how we feel about the teletransportation paradox. I don’t really want to talk about that here at the moment.

So let’s go back and look at wormholes again shall we?

I’m not going to go too in-depth on what a wormhole is, partly because physics isn’t my strong suit, and partly because I’m going to assume most people reading this have encountered wormholes in fiction before. Also, I’ve been rambling on for pretty long already. Let’s just say that general relativity equations have valid solutions that allow wormholes – some of which could be traversable – but that the existence of space-time wormholes has not been proven.

We have however been able to create a different type of wormhole. In 2015, scientists created a ‘wormhole’ that made a magnetic field transmit from one point in space to another, without being detected en route. This technology has interesting implications for making invisibility a possibility, but doesn’t help us explore the galaxy. At the moment we have no idea how to create a traversable wormhole, or even if such an undertaking would be possible.

In fiction though, it’s a different story.padoras-star

In Pandora’s Star by Peter F. Hamilton, two college students in a rundown lab manage to create a wormhole, which they then use to gatecrash the historic first Mars landing. From there, we get an eight book series about an interstellar commonwealth connected by wormholes. Unlike most series, these wormhole gates aren’t put in space, and spaceships are few and far between. Instead, wormholes are on the surface of the various planets, and the most common way to travel through them is via train. In this setting, you go to a train station, get on, then after going through a tunnel you’re on a new planet. Simple. People in the Commonwealth often commute between planets. The other week I took a train to Sydney; That took almost two hours. If I lived near an interplanetary train station in the Commonwealth, I could catch a train and end up on another world in less time than it currently takes me to get to my closest big city.

This is my favourite method of interstellar travel. Imagine being able to travel to so many strange and new planets so easily. It’s also a method of travel that would be relatively cheap, easy, safe, and widespread enough for everyone to make use of. It helps that Hamilton created a huge variety of amazing worlds for his characters to catch the train to. Hopefully we’ll find just as many wonderful worlds once we get to exploring the universe. If we don’t, then there are other advantages of having wormhole trains. Hamilton’s books have an express loop train that thanks to the wormhole tunnels can travel to a number of major cities on Earth every ten minutes. Imagine how much easier that would make your next holiday?

As much as I want to be able to take a train to another planet, I do understand that at the moment it’s almost as unobtainable as a Millennium Falcon. But damn, that would be one hell of a way to open up the galaxy.

I suppose there is one other question that needs to be asked. When railroads and telegraphs first appeared, they effectively made the world smaller. One popular term at the time was ‘the annihilation of space and time’.  Don’t believe me? Next time you order something online from overseas, think about how long it would take for it to arrive if you had been living before the industrial revolution. Unless you walk everywhere, the world is much more accessible, and for practical purposes smaller than it was for most of history. So I have one question to leave you with today. If we do gain the ability to casually travel between the stars, would that make the universe smaller?

Could our universe ever be considered small?


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