Biofuels in Space! Or, What the Heck is Microgravity?


Function: noun

Etymology: micr- + gravity

: a condition in space in which only minuscule gravitational forces are experienced : virtual absence of gravity ; broadly : WEIGHTLESSNESS

—via Merriam-Webster

Just as black holes do not suck, there is technically no such thing as zero gravity in low-Earth orbit. Earth’s gravitational influence, after all, is what keeps the moon tied to our home world, so how could there be no gravity between it and us?


Plants … in … spaaaaace!

—Illustration by Dale Gustafson, National Geographic Stock

Instead, objects in orbit are really in a constant state of freefall, like being stuck on a roller coaster just as the car tips over a rise.

In fact, to create the sensation of being in orbit, those “zero G” tourist flights are doing nothing more than making roller coaster-esque swoops and dips in the sky.

What people in space experience is known among the science crowd as microgravity, and its effects have been studied on everything from protein crystal growth for pharmaceuticals to mammalian reproduction.

Quite a few experiments done in space have been focused on how to overcome the negative aspects of microgravity, such as weakened bones and skin rashes.


Astronaut Jeffrey Williams doing plant cells vs. microgravity experiments aboard the ISS in December 2009.

—Image courtesy NASA

But the newest experiment now aboard the International Space Station is shining a more positive light on weightlessness: growing plant cells to meet Earth’s energy needs.

National Lab Pathfinder-Cells 3 was launched on the space shuttle Endeavour last month and will run on the ISS until Discovery brings it home in April.

The experiment is growing cell cultures of Jatropha curcas, a plant that produces an oil that can be converted into an alternative, bio-based fuel.


Jatropha cells ready for transport to the ISS.

—Image courtesy Wagner A. Vendrame, University of Florida, Homestead

“Our goal is to verify if microgravity will induce any significant changes in the cells that could affect plant growth and development back on Earth,” study leader Wagner Vendrame, of the University of Florida, said in a statement.

Jatropha is a buzzword in the biofuels sector, since some experts think it could help ease the burden of growing crops such as corn for biofuels.

That’s because jatropha is a hardy, drought-resistant plant that can be grown on lands not currently in use for food production.

The problem with growing jatropha as a commercial plant is that it hasn’t yet been fully domesticated, so crop productivity can vary, no one is sure what pests or diseases might pop up when growth goes large-scale, and there’s a chance its seeds and leaves might prove especially toxic.


Jatropha, all growed up.

—Image courtesy Wagner A. Vendrame, University of Florida, Homestead

Enter microgravity experiments on jatropha, which aim to show how life in freefall might lead to a commercial variant of the plant via changes in its cell structure, growth speed, and gene expression.

NASA, by the way, has a vested interest beyond helping humanity with its energy demands: Oils from jatropha are “of excellent quality and amenable for jet fuel mixes,” according to the Cells 3 Web site.

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