Could we grow rocket fuel on Mars?

One of the biggest challenges with going to Mars is what to take with you. Every bit of weight has to be justified and taking lots of stores with you would be hugely expensive. One idea that has been suggested to get around this is to 3D print things there using materials found on Mars. But could we grow various resources such as oil, food or even oxygen by manipulating bacteria? Professor Lynn Rothschild is an astrobiologist at Brown University and NASA and she' described the new field of synthetic biology to Kat Arney...

Lynn - There are all sorts of fancy definitions but the easiest way to look at it is that we're able to do something new with biology. So, whereas we don't hear as well as a bat or run as fast as a tiger or whatever, if we could have those capabilities, if we can mix and match the genes, we could do all sorts of wonderful things. And the same would be true of a bacterium or an alga or a plant or whatever that you can give it new capabilities that it never had before or perhaps no other organism on Earth ever has had.

Kat - So say, you want some bacteria to make rocket fuel. You could do that?

Lynn - Absolutely. I mean it depends what you're running your rocket on but certainly, organisms make fuel. In fact, every time you turn on your car, you're burning products from organisms. They happened to have been dinosaurs. But there's no reason that you couldn't use organisms to make fuel on Mars.

Kat - How does this actually work? Say, we're going to Mars and we want to have this manipulated bacteria there, what do you need?

Lynn - We need some sort of infrastructure just like you have in the lab and I think the best way to imagine it is if you've ever been through a distillery or a beer production facility. You have vats where you have microbes in the case of beer for example, there are yeast cells that are metabolising some kind of input whether it's grass or whatever. And then they're producing alcohol. Instead of grass, we would be using other sorts of photosynthetic organisms. Probably, some sort of a microbe like a cyanobacterium. If you're very old like I am, we used to call them blue green algae. For your production organism, we might be using a yeast cell, as you say, we might be using a bacterium and then you're able to produce honestly, anything from a leather simulant to food, to perfume, to clothing, to rocket fuel. I really believe that we could make just about anything you need using biology.

Kat - In terms of the actual DNA stuff, how would you take that?

Lynn - Well, it's easy because if you're taking a human, you're taking lots of DNA. In fact, not one of the spacecraft we have ever sent anywhere has been completely sterilised. So, we've already sent DNA all over the Solar System and beyond. In terms of bringing up small quantities, we could certainly do that in cells. We're working right now with a particular bacterium, Bacillus subtilis, that forms a very resistant spore. These spores have been flown out on space on satellites for over 2 years so we know they're highly resistant so we could send the DNA in a spore form, we could dry it and send it. But ultimately, we won't even want to do that. We're going to want to break this physical link. And so, what we'll want to do is on the Earth, send information to how to make new DNA and the colonists on Mars will take that information and actually print new sequences of DNA.

Kat - From my understanding of synthetic biology, it's a lot about having kind of standard components and parts, almost like a library that you could just pick and choose. What kinds of properties could potentially be put into bacteria that we could take to Mars?

Lynn - There's a very, very active community working on this on planet Earth for Earth-based applications. So, people are already involved in all the sorts of things that I mentioned - from perfumes and fuels to certainly, antimalarial drugs, other sorts of drugs. But the real conceit of all this is that when you take up for example a computer, you're lifting up a lot of mass into space and your computer goes bad, what do you do? You can't really call for another one to be delivered the next day. And so, you're going to have to deal with what you have and biology as a technology has incredibly appealing properties. The big one is that it replicates itself. I mean, if you had computers that replicated themselves, no big deal or your clothing, you put down your trousers in the evening and there are two in the morning that would be great. But that's not the way physical things work, but that's the way biology works. Furthermore, if it's damaged, it can repair itself. And so, when you start to think of biology as a technology, it opens up all sorts of possibilities.

Kat -   Would there be risks then of releasing these manipulated bacteria on Mars?

Lynn -   The biggest problem with sending things to mars is that there is a possibility that there is an indigenous Martian biota. Honestly, that would be the biggest scientific discovery in the history of biology if we found a second life form, and particularly, if it was in the next planet over. So, if we send astronauts and all these organisms and so on, and we destroyed our possibility of finding the second life form, that would be an enormous scientific tragedy.