Generation Ships – Stop the world I want to get off

NASA-Apollo8-Dec24-EarthriseIf you are wanting to opt out of the cradle of humanity, there really isn’t a viable option at the moment. Our attempt to move humans elsewhere has been thought about in great detail in a variety of scientific thought experiments and of course, science fiction stories. It is however still not a reality.

The reasons for throwing all of your possession in a transport vehicle and clearing off somewhere else range from finding a better life to avoiding famine, plague, disasters or conflict. Maybe there is better resource availability or more freedom. Of course it could just be pure greed that is motivating you. Earths capability to support the current population growth and resource usage is slowly but surely moving towards the no return tipping point.

There are a number of movements and organisations theorising and researching into how we can make life here more viable and long term sustainable. Everything from crop improvement to recycling and better resource usage is being investigated to try and extend our current lifestyle. Other organisations are looking at how we can bring resources from elsewhere, such as astroid capture. In the longer term there is research into colonising other locations in our solar system such as the Moon, Mars and the Asteroid belts.

None of these however get humanity out of the solar system. The reality is, in order to increase the chances of not going the way of the dinosaurs, we will need to get ourselves out to another planet. Somewhere that we can use as a backup if the primary source of humanity decides to eat itself.

A lot of people will ask why should we invest in any sort of off planet project, when there are so many problems to solve here already?

I can appreciate their point of view, but I think it is a little narrow in its vision. If we think of the earth as a closed environment, we will eventually reach a point where it can no longer sustain itself. Like a giant terrarium or bottle garden, it will seek to correct itself or die. The idea of a Generation Ship is a strategy so that we can start again elsewhere and maybe get it right this time.

A counter argument to the why should we do this folks, is progress. Any mass project of this sort will eventually lead to technology that will be beneficial to us. We will however, need to be careful that this beneficial technology does not drive us to the tipping point quicker.

Take a look at the various challenges below and think on the various hurdles that we will need to overcome in order to make this kind of undertaking viable. Every one of the solutions to these challenges can have a beneficial effect to the planet we are planning on leave behind.

What are the challenges?

The Gravity Well

Space Elevator Climbing - Liftport [GFDL ( or CC-BY-SA-3.0 (], from Wikimedia Commons

Space Elevator Climbing – Liftport [GFDL ( or CC-BY-SA-3.0 (], from Wikimedia Commons

In order to build a ship of the magnitude that is capable of interstellar flight, we will need to construct it in orbit. We will thus need find a better way of getting out of our gravity well. The only way to get out of our atmosphere at the moment is to use rocketry.

Recent advances such as Project X have resulted in auto piloted systems that can supply the ISS, but they are certainly not an everyday bus or cargo service to orbit. To create the number and rocket vehicles of a size required to place facilities capable of building a Generation ship in orbit, would require a huge amount of resources and energy to build and fuel them.

There are a number of projects that are the first steps to more efficient or lower cost reusable orbital vehicles. Eventually however, we are going to have to come up with more advanced alternatives such as space elevators, sky hooks, space fountains or “great big honking space guns” to quote Colonel O’Neill. There is also the more fanciful matter transport.

Any of these options are so far ahead of our current scientific knowledge, they are firmly in the science fiction realm. Thankfully, folks are still researching them, such as the folks at Lift Port.

Examples from Science Fiction and Fantasy:

For the Space Elevator idea, look at the Mars Trilogy by Kim Stanley Robinson. This concept relies on highly advanced diamond based materials that could take the strain of being anchored on the planet and swinging an attached asteroid about. In Summertide by Charles Sheffield, the Umbilicle is an Alien artefact that solves the problem of this stress and strain by reeling in or paying out cable via a “hole” in space.

Sky Hooks are rarely mentioned and the only one I can remember reading about was in The Last Theorem by Arthur C Clark and Frederik Pohl.

Space Fountains are a variant of the space elevator concept that does not involve the use of a tethered, orbiting platform and is covered in yet another Arthur C Clark novel, the Fountains of Paradise.

For “great big honking space guns” we are of course referring to Rail Guns or Mass Drivers. As you may have read elsewhere, these are being researched and tested by the US Navy. The size of device required to put something in orbit has been calculated, but is still beyond us. There are many examples of Rail Guns in Science Fiction Literature, mostly as inter-ship weapons or the means of projecting cargo back to earth, for example Pushing Ice by Alastair Reynolds or “The Moon Is A Harsh Mistress” by Heinlein

As a means of achieving orbit from the Earths surface, there are actually very few stories. The classic is of course Jules Verne’s From the Earth to the Moon, but technically that was just a big gun. Part of the problem I think, are the extreme forces involved for whatever is fired into orbit. The number of g’s that any passenger would experience would be high enough that special equipment would be needed to prevent them being pulverised or seriously injured. The same goes for the cargo, it will need wrapping up pretty securely. The cost per launch would however negate the these costs.


By Darjac (Scanned by Darjac) [Public domain], via Wikimedia CommonsOnce we are up in orbit, facilities to build the ship will be needed. These will need to become self sufficient in a number of areas to be viable. You will need a crew, you will need accommodation for the crew. You will need air, food, heat and gravity.

So, that’s just for the personnel. To create anything else, manufacturing facilities will be required that are capable of producing everything, or you will be back to the gravity well problem. These production lines will need to operate in either zero or low gravity conditions.

Once you have designed and built the machines, you need to provide the raw materials that they will consume and transform.

The resources on our planet and solar system have come ultimately from the Big Bang. Hydrogen, helium and lithium are what this initially produced. This Hydrogen was fused into elements up to the mass of iron by the cores of stars. Most of the stuff heavier than iron gets made in type II supernovae when suns collapse and ultimately explode. This flings these heavier elements out with the blast. So unless we are planning to make our sun go supernova, we will need to source our extra resources somewhere other than Earth.

Local sources other than Earth, will include the Moon, Mars or involve swinging in rocks from the asteroid belt or exotics from the Oort cloud. This will mean that you will either have to set up either an automated resource gathering operation, or you will need to send folks out there. Again if it is the latter, then you have the same set of challenges to overcome.

Examples from Science Fiction and Fantasy:

We already have a Space Station in the form of the ISS. What we do not have is a Habitat. Somewhere that is permanently occupied and is self sustaining in some manner. There are many, many examples of this type of thing in Science Fiction. Entire TV series such as Deep Space 9 and Babylon 5 used the concept of the habitat to provide a central location to allow further story telling. It’s also cheaper for set building, but that is another matter.

In Literature, the book that got NASA thinking about this sort of thing was The High Frontier by Gerald K O’Neill. As far as story telling goes, Colony by Ben Bova and Joe Haldeman’s Worlds series look at Habitats being our last bastions of hope when everything goes to pot down below. In the Near future category, William Gibson’s Neuromancer trilogy does a good job of describing how the rich and powerful have retired up into orbit, whilst in the Far Future category, Alastair Reynolds does a good job of describing life in the Glitter Band and how civilisation could function in The Prefect.

Life support

Biosphere 2 - By Jeangagnon (Own work) [CC-BY-SA-3.0 (], via Wikimedia Commons

Biosphere 2 – By Jeangagnon (Own work) [CC-BY-SA-3.0 (], via Wikimedia Commons

There have already been a number of studies into how humans can grow food and generate enough air for the journey or for the colonisation effort at the other end. Like the Terrarium example I gave earlier, a close self perpetuating system would be needed that has a cycle that would include a variable population.

Experiments into this type of thing have been going on for a while. For example, BIOS-3 was originally set up in the sixties and is now, with help from the European Space Agency, back in business. There is also the famous Biosphere 2 in Arizona.

All of these have found excellent ways of harnessing natural resources such as Algae, but they have all suffered from the over production of one thing or another. The delicate balancing act is not yet fine tuned enough to be self sustaining. All have needed correction via release of excess gasses to the need for the input of materials. The former is ok on a journey, however the latter is not possible once you have left unless there is somewhere to harvest on the way.

Examples from Science Fiction and Fantasy:

Two films come to mind, the very entertaining but scientifically dubious Silent Running and the more recent offering from Danny Boyle, Sunshine. The former is shows how having a living plant bank in space may be needed at some point to re-populate a dying earth, whilst the later touches on how vital any garden is on a long space journey as it provides the food, the waste treatment and the gases required for survival.

Hydroponics seemed to be the favoured idea in the seventies and eighties, whilst the scientific community, with the advent of Biotechnology, swung more towards the use of algae and microbes for that can be used for the building blocks of cultured food.


By NASA/Marshall Space Flight Center [Public domain], via Wikimedia CommonsAfter life support, this is probably the next most important thing to get sorted. The ideas to propel us out into the stars are numerous and all completely theoretical.
Solar sail, Ramjet or Scoop, beam riding & Nuclear detonation are just a few of the possible methods.

All of which are sub light. If we want to look into the science fiction realm there are warp drives, dimension tunnelling and alternative universe jumping.

Just recently, the whole theoretical idea of the warp drive was revised by NASA. Now it seems that it wouldn’t need an antimatter ball the size of Jupiter as per the Alcubierre design. Now it’s only 500 Kg of something we haven’t quite got yet. The Alcubierre design theorises creating a bubble that would warp but the ship inside would not travel faster than light.

So unless we have a major break through to bring practical application to the theoretical physics models, we will be doing this the long, time consuming way. How long you ask? Well if you look at the voyager project, it is only now passing out of the solar system (or not depending upon where you draw the border). It has taken a few detours to take in the planets, but it does give a good indicator how long these things will take.

To complicate matters, there is also the whole Einstein theory regarding relative ship time getting slower as we approach the speed of light (c). Based on this theory, a crew would only experience a short period time of year but back on earth, a long period would have elapsed. We have no empirical data regarding this, but the motif has been explored by numerous science fiction authors.

I’m not a physicist, so all of this can at times tie your brain up in a knot. If you want to do that, go and look at the FTL page on wikipedia.

Examples from Science Fiction and Fantasy:

This is either examined in minute detail, side stepped or ignored completely. After all, why let current scientific theories get in the way of a good story.

Poul Anderson’s Tau Zero gives a nice summary of the issues regarding this, whilst John Scalzi talks about the skipping into an alternative identical universe in Old Man’s War


By Rama (Own work) [CC-BY-SA-2.0-fr (], via Wikimedia Commons

By Rama (Own work) [CC-BY-SA-2.0-fr (], via Wikimedia Commons

So if it takes this long to get anywhere, then what about the crew? This is the reason for the succinct Generation ship name. It will probably be the descendants who reach the far flung planets and not those who set out. If however we are able to extend our longevity, then the number of generations required is reduced.

Research into this are is far reaching. Indeed just recently, it was announced that the life of some lab mice was extended from an average of 900 days to one of 1200 days. Not quite the amount extension we are looking for, but it is a good start. This was achieved through the suppression of a chemical produced by the hypothalamus 

The key to this type of thing will no doubt be found in the next twenty years or so. As our knowledge of what things control the body, we will become confident that we know which combination of switches we will need to throw to stop or slow down the ageing process. In combination with this, as our knowledge of genetics and gene therapy improves, I will not be surprised if we not able to renew ourselves through treatments.

There is also the idea of actually cheating the journey by placing yourself in some sort of suspended animation or cold store. This will still need some sort of custodian. So this will either be an automated system, a long lived person to act as a caretaker or a crew dedicated to keeping all the systems going. The later one will end up with two very diverse populations upon reaching the destination that are separated culturally by many years and new ideas.

Who knows the consequences of this elongated life that we are craving. How will we deal with it? The thought of living an extremely long life is appealing. Lots of time to take everything in. It will however fill up the Earth with even more people than before unless the Generation ship project is in full swing. There is also the idea of life fatigue, where you really do get to a point of wondering if it is worth going on as you’ve probably seen and learnt all you want to.

Examples from Science Fiction and Fantasy:

John Scalzi touches on this briefly in Old Mans war with how they deal with octogenarians. I won’t spoil the surprise, go read it. Kim Stanley Robinson talks about regenerative treatments in Mars trilogy and

Alistair Reynolds has a great bit about the how generation ships could fair in his novel Chasm City, whilst Stephen Baxters novella Mayflower II postulates the fate of a ship under going an immensely long journey.

Scott Westerfeld’s Succession novels talk about a civilisation using some sort of suspended animation or coldsleep to allow it to deal with the long time periods star ship personel are away.


Mars Colony Concept - By NASA Ames Research Center (NASA Ames featured images) [Public domain], via Wikimedia Commons

Mars Colony Concept – By NASA Ames Research Center (NASA Ames featured images) [Public domain], via Wikimedia Commons

Assuming the planet that you arrive at is habitable, see Terraforming below, you will need to quickly assess and choose a site to make your mark at. This initial site may involve landing part of your generation ship, dropping purpose built habitat ships to act as first buildings or just huge cargo carriers with all the building materials the colonists will need to set up shop.

There are however a number of things that will need to be assessed before you commit. Is the flora and fauna friendly? What are the best parameters for that first site to allow for success?

There would be nothing worse than setting up in a location that you find out at a later on has a factor that results in your colony failing. This could be something as simple as a microbe, right up to local solar system issues like asteroids or solar flares.

This can of course be mitigated by sending an advanced party of humans or an automated exploration team that can do all the research work for you. This however runs the risk that any advanced party may end up being culturally far different from the colonist arriving at a later date due.

Examples from Science Fiction and Fantasy:

These are many and varied. The original colonisation stories (Dragons Dawn) behind the Dragons of Pern indicated how an established colony can be devastated by a phenomenon that only comes around every three hundred years or so due to the planet’s orbit.


Once you get to your destination, there is no guarantee that any planet that you were aiming for is completely suitable for colonisation. Some tweaking may be needed. This terraforming might be to raise the average temperature a bit or adjust the atmospheric mix.

The opposite extreme of this is a full on terraform project. This may require local water based asteroids being rammed into the surface or long term gas extractors being deployed to give an atmosphere that is suitable.

Thus the first generation of humans present during arrival at a planet may not even get to the surface and you are back to some of the issues mentioned above.


Terraforming is something that will be very important. The number of planets out there are still being counted. The type of planet suitable for humans is a small fraction of these due to the narrow parameters that we are able to survive under. Thus we will need to learn how to adjust anything we find even remotely suitable.

Examples from Science Fiction and Fantasy:

The consequences of messing about with the local wildlife in The Legacy of Herot by Larry Niven, Jerry Pournelle, and Steven Barnes.

The Mars trilogy by Kim Stanley Robison gives a very good view of what would be required or happen for a full terraform.


I was prompted to write this article when I came across the 100yss project which has the aim of getting human beings to another solar system within a hundred years. It’s a bold mission statement that I will probably never know if it succeeds, that is unless I have another 100 years put on my clock. Even my son, who is currently three, may not know the answer. This truly is a generational project. Not only do we have to get the thing built, but it will need to navigate to another solar system at sub light speeds. Thus maybe my grandchildren may know if it is a success, maybe not even them.

There is a great section on their mission page called reality check:

“The concept of humans traveling to other star systems may appear fantastical, but no more so than the fantasy of reaching the Moon was in the days of H. G. Wells. “The First Men in the Moon” was published considerably less than 100 years before humans landed on the Moon (1901 vs. 1969), and the rapidity of scientific and technological advances was not nearly as great as it is today. The truth is that the best ideas sound crazy at first. And then there comes a time when we can’t imagine a world without them.”

This “we aren’t as crazy as we sound” statement is firmly aimed at the skeptics of this sort of thing.

The incredible mind leap for me is who is prepared to crew a ship that will never reach the destination whilst you are alive. It’s a real logical conundrum. Who would do this sort of thing? Well as mentioned above, anyone whose current living conditions are less than desirable or anyone with a huge sense of adventure.

One item that I haven’t mentioned is what happens if FTL is conquered during your voyage? I bring this up as I remember the Tharg future shock of a ship arriving at an already colonised planet due to FTL being discovered after they left but they decided to allow them to continue their journey as it was too difficult to wake them early. A nice surprise for the ship colonists? A mixed bag of reactions I think.

This is a project of mammoth proportions, so how can we acheive it? To subvert the saying, one mouthful at a time.


I’m starting a new selection of articles that fall under the banner of “Are We There Yet?” that will discuss the various ideas that have been written about in Science Fiction and how close we are to them being a reality. The Generation ship will take pride of place as the first one. To find out more look here.


The 100yss Project
100yss at SWXS
New calulations for FTL

My recommendations for further Science Fiction reading around Generation Ships and Colonisation:

The Legacy of Herot by Larry Niven,

Dragonsdawn by Anne MacCaffrey,

Chasm City by Alastair Reynolds,

Red, Green and Blue Mars by Kim Stanley Robinson,

Ark by Stephen Baxter

Can you suggest any?

Joe Emtigoe is the pen name of Joe Molloy, who is a freelance technical consultant, project manager and writer, based in London, UK.

Joe is in the middle of writing his first novel called "Heartless Sun".