Launching a rocket into space takes a lot of energy. Compared to the gasoline used everyday to power automobiles, the special fuel used in rockets needs to be extremely light while packing in an extraordinary amount of energy.
NASA's X-fleet space shuttles use propellants such as JP-10. JP-10's unique molecular arrangement, where uniquely shaped rings of carbon give the fuel a high energy density — a metric used for the amount of energy stored per unit volume. Shuttles carry a typical fuel load of over 500,000 gallons. At $25 per gallon, unsurprisingly spaceflight is an expensive proposition.
A team of researchers at the Georgia Institute of Technology may have come up with a cheaper and more sustainable energy source: bacteria. The scientists developed a genetically-engineered bacteria that produces a biosynthetic fuel called pinene which, in its dimer form, has a similar energy density to JP-10.
Image Credit: ACS
Pinene is a hydrocarbon that is naturally made by trees. But it's hard to extract it in usable amounts for fuel, so scientists decided to take the genes that produce it and insert them into bacteria. “There’s no way we could grow enough trees to make the tactical fuel,” lead researcher Peralta-Yahya says. “What we need is a new source of pinene.”
Initially, after being fed with glucose the modified bacteria could produce the fuel, but only in low amounts. So the scientists decided to rearrange the two plant-based genes that produce the fuel so that they resided next to each other in the bacterial genome. In this configuration the components that make up the fuel immediately come into contact after being produced, increasing the yield by 6-fold.
However, there's still quite some improvement that needs to made before all the jets, rockets and missiles in the world are powered by something that's more eco-friendly than fossil fuels. To compete with JP-10, the bioengineered bacteria would need to produce 26 times more pinene. Large amounts of pinene production is toxic to the bacteria, so to make more fuel, researchers will need create bugs that are more resilient to an environment that's saturated with the molecule.
Image Credit: Nature
If they can achieve this reachable goal, an exciting future is in store. So far genetically engineered bacteria have helped humans to drastically improve our health, clean up the environment, and extract valuable metals from the Earth. Soon they could also help propel us into space.