Rocket fuel making algae farms on Mars could bring future colonists back home

One of the most common but odd questions that I get asked when I do my keynotes is how Elon Musk’s vision of using SpaceX rockets in 2024 to travel from one side of the planet to the other in 40 minutes or so at Mach 27 will be environmentally sustainable. The answer at the moment, obviously, even with NASA’s latest “green rocket fuel” technology, is no.

Now though, just a year or so after researchers discovered a new way to grow fresh nano-bionic plants on the Martian surface, researchers in the US might have just cracked the riddle of creating not just green rocket fuel, literally, but rocket fuel that is sustainable and possibly carbon neutral - although would that really matter on the Red Planet? Answers on a postcard please ...

This week the folks at the Georgia Institute of Technology showed off their latest concept for building an algae biofuel farm on Mars. Since the algae biofuel market has been slow to catch hold on Earth, despite Virgin Atlantic using it in their trans-Atlantic planes, it almost comes across that the team thought what the heck, why don’t we try it somewhere else like on Mars.

Courtesy: Georgia Tech

If that mental leap doesn’t make quite sense though consider Georgia’s emerging role in space exploration and then all of a sudden the idea of using biofuels to produce a renewable rocket propellant on the red planet starts to make complete sense. Obviously.

The idea was put forwards by Caroline Genzale of the George Woodruff School of Mechanical Engineering at Georgia Tech, who is also a NASA Innovative Advanced Concepts Fellow who had this to say:

“The goal of [this project] is to engineer production of a renewable, liquid, rocket propellant on Mars. In situ production of rocket propellant has the opportunity to reduce initial payloads from Earth, reducing launch costs by billions of dollars. The process centers around photosynthetically grown algae, cultivated using Martian carbon dioxide and sunlight, and feeding the digested algal biomass to an engineered microbe to produce rocket fuel.”

Genzale says the fuel would be based on compounds called diols. Among other advantages she also says that diols would yield a cleaner burning fuel, which could potentially enable rockets to be used multiple times – something that dovetails perfectly with SpaceX’s vision of using fleets of reusable spacecraft as Elon Musk zero’s in on his lifetime ambition of colonising the red planet.

“The Martian environment poses a really interesting set of challenges, from identifying novel propellants that can be produced using only Martian resources, to actually building a rocket propellant plant more than 36 million miles away from Earth with minimal to no human labour,” she added. “If we’re successful, we’ll be one critical step closer to realising a sustainable colony of humans living on Mars.”