In Interstellar, how could you build a space colony without bringing the Blight with you?

In Interstellar, there is a Blight destroying all the world's crops. If Plan A involves launching a space colony, presumably full of crops, etc., how could they avoid bringing the Blight with them?

At the end of the film we see that they've actually created space colonies. How did they manage to launch and populate them without bringing the Blight with them?

• @Red_Shadow - Done. Someone should really add the syntax for the spoiler blockquote to the editing instructions on the right side of the editor. I'm not a newbie when it comes to StackExchange, but the only way I could figure it out was by editing another question with a spoiler block in it. – Scott Whitlock Jan 29 '15 at 21:09
• It's there, in the advanced help under the section Stack Exchange additions, sub-section Spoilers. However, I admit that it's not very visible and a little hard to find. Could have a better placement. – SylvainL Jan 31 '15 at 11:57
• It depends on how the Blight is spread I suppose. Control those vectors and you control whether it comes with you into space. Anyway, have a Nice Question badge. +1. – ouflak Mar 11 '15 at 15:04
• In the film, they said that the Blight feeds on Nitrogen from the atmosphere -- is it possible that the space stations replaced nitrogen with some noble gas like neon or argon? They'd still need to supply a mechanism for nitrogen fixation for the plants, but that doesn't necessarily need atmospheric nitrogen. – Johnny Apr 20 '15 at 18:14

Common agriculture

Many current diseases of wheat and other crops are mitigated by chemical treatment of the seed grains - you can do pretty harsh things to them that will kill many different kinds of bacteria but still leave a seed that will germinate. It doesn't make them immune, but it allows you to re-plant them in a new disease-free location.

This is pure speculation, but if similar things are done right now, then a similar procedure could be developed to "cleanse" seeds of Blight.

Quarantine

Another common option is to identify some spots that aren't yet reached by the disease and use them to gather clean seed stock before it's too late. If really all (100% not, say, 99.9%) the world's crops are destroyed, then it still leaves seeds that are stored securely in the few isolated 'seed banks' that we have. Again, they won't be immune and need to be planted in a safe location, but even if you have a very small number of seeds (say, a dozen grains) then you can reproduce them in large quantities if you have a need and resources to do it.

• Note the scene where Cooper arrives at NASA and is shown scientists in a clean room examining some blighted plants. I assume that's part of a quarantine process. – Fhnuzoag Feb 2 '15 at 14:13

There are many seed banks around the world today that store a considerable selection of the world's existing plants. For plants whose seeds are not recalcitrant and have been stored securely in one or more of these banks, they could presumably be later transferred securely and used as a foundation for future crops. As long as procedures are taken to ensure that the Blight is not transmitted by its typical vector (air?, physical contact?, water?), it seems plausible.

Securing some Blight-free plant samples should be straightfoward. In principle all you need is one cell from which to clone the rest of a plant. The Blight is described as a fungal infection, so you only need to make sure you don't take any Blight cells with your sample for cloning.

The difficult part is having a Blight-free environment in which to grow your crops. If you stay on Earth, then no matter how well sealed your habitat, sooner or later some of the outside atmosphere is likely to get in and bring the Blight with it. A space habitat avoids this difficulty, especially since the water and construction materials could come from asteroids which had never been part of Earth's biosphere.

As long as you observe strict quarantine and thoroughly de-Blight everything and everyone that comes off Earth, it should then be possible to have a Blight-free growing environment in space.

• Except it seemed like, in the movie, that they were constructing the habitat on Earth. – Scott Whitlock Jan 31 '15 at 15:56
• The Earth-built habitat could be an initial "bootstrap" effort to get people and equipment out of Earth's gravity well. After that, you could build additional "clean" space habitats out of non-Earth materials. – Royal Canadian Bandit Feb 2 '15 at 11:15
• @Royal Canadian Bandit -- The idea was that they built the habitats on Earth and launched them into space once they had "solved gravity", by temporarily altering the gravitational constant to decrease the Earth's gravitational field--see my answer here. – Hypnosifl Mar 11 '15 at 16:16
• Besides we already use various methods to sterilize whole facilities now (e.g. $\gamma$ irradiation by exposure to $Co^{60}$). So build the facility, evacuate it, irradiate it, have passengers go through clean room procedures, and you're all set and ready for planting. – Jim2B Jun 18 '15 at 2:24

It's nowhere explicitly mentioned in the film as it obviously tries to steer away from eco-political issues, but it should be plain obvious that Blight is not a mysterious plague suddenly striking a planet that's otherwise in a perfect state but a plant illness that now exploded, in opposite to those millions of years previous to that, when Earth had a stable and healthy biosphere and that illness was controlled by nature's balance. Obvously, the balance toppled, now in favor o the illness.

No matter what habitat and how perfect the environment - as soon as you grow more than just a few plants in a lab, you will always have either parasites or microbes or spores liking a plant just as you do, sooner or later you will always have to help a plant by some means of assistance: a bit more light, a bit more or less water, more or less fertilizer, some antiherbal or antiparasitic remedy, whether chemical or biological. It's impossible to evacuate people from the planet on a larger scale without bringing some spores and microbes surprises with you. The difference is: in a clean habitat atmosphere on the cooper station, for example, if done right, then those remedies will work again like they once did on Earth. The plants on Earth were weakened first before Blight could kill them.

• Actually, the biosphere of Earth has seen an even worse self-inflicted apocalypse than that proposed in Interstellar. It is called the Oxygen crisis and it resulted in the near extinction of all anaerobic life. What remains of anaerobic life only fills tiny niches in Earth's biosphere now. – Jim2B Jun 18 '15 at 2:26