The author job is to insert 10 microliters of fluid into a microplate and watch as crystals grow. Ten microliters amount to a single droplet from his pipette, so Arnold must be exceedingly precise which is a challenge, because he is floating inside the International Space Station. Arnold repeats the process 96 times, filling small cells in the microplate with a solution mixed to grow protein crystals. He also tests ways to mix the solution with crystal-seeding material. 

A week later, the companies behind the experiment release the results: the crystals are blooming. Growing crystals in orbit is a big deal. Researchers have proven that crystals grown in space contain fewer imperfections than those growth on Earth. The mechanics behind this fact are disputed in the crystallography community (really, don’t get them started), but the accepted cause is that crystals grow more slowly in microgravity.

Protein Molecules

Protein molecules will move around inside a fluid cycling like a buoyant fish tank decoration making the crystals grow faster and smaller. Outside of Earth’s gravity, protein molecules move and therefore crystalize via randomized diffusion. This leads to more orderly crystal growth and fewer impurities, which in turn makes it easier for drug companies to study specific proteins.

Proteins are the key to much of the body’s functions, but studying individual protein molecules is extremely difficult because they are so small. However, clever researchers have figured out that growing a crystal from protein molecules will create a repeating array that can reveal the molecular structure. If they know the protein’s structure, they can design medicine with it.

They know the structure of what a protein looks like, you can then better design molecules to fit it into that protein and turn it on or off,” cancer researcher Kenneth Savin recently said during a NASA tour of a treatment center. “That's the basis for a lot of drugs.”

Breaking Bad in Orbit

Previously, protein samples had been flown to the ISS, crystallized in microgravity, and then returned to Earth. Back on the planet, researchers could analyze the results of the experiment and, often, and the launch and experiment all over again to test the crystals under optimized growth conditions.


The current medical research on board the International Space Station is a reminder of the benefits that routine spaceflight could bring. Humanity now has only a toehold in space, and microgravity science is so new that the equipment to do it is just now being developed and tested.

Making the crystallization process cheaper is a good way to spur more research. When people talk about industrialization of space, they may not think about a cure for cancer. But the key to that kind of breakthrough may one day be found overhead, in low Earth orbit.