A three-person crew of astronauts—two Russians and an American—blasted off this morning from Kazakhstan, en route to the International Space Station. During their six-month mission, when they're not taking spacewalks or eating space food, the trio will conduct experiments associated with the development of an AIDS vaccine. Why develop a vaccine in space?
Because the lack of gravity makes it far easier to grow protein crystals. Pharmaceutical researchers rely on protein crystallization, the process by which protein molecules—the building blocks of both viruses and vaccines—are made to form crystals, solids in which the various atomic components are arranged in regular, repeating patterns. Once the proteins crystallize, their structural properties can be carefully scrutinized using X-ray crystallography. This analysis is critical because a protein's function is dependent on its structure.
The problem is that growing protein crystals is a lot easier said than done—at least on terra firma. The more complex the protein, the harder it is to crystallize. This probably has something to do with the effect of gravity, which puts stress on the atomic structures of these complicated molecules. But in the near weightlessness of space—"microgravity" in NASA parlance—growing protein crystals is a much simpler task. Not only is it relatively simple to crystallize proteins, but the crystals grown can be much larger—10 times larger, according to past space shuttle experiments. And space-grown crystals are typically free of clumping and other imperfections that complicate the analysis process.
The ease of crystallization isn't the only benefit of celestial drug research. It's also known that microbes—a key component in antibiotics—grow much more efficiently in microgravity environments. In addition, genes can be more readily spliced with foreign proteins, which has led some researchers to believe that edible vaccines could be manufactured in space: The measles vaccines of tomorrow could be delivered via potato, rather than injection.
Drug companies would love to build vast factories in space, but that's obviously not in the cards anytime soon. There may be some Earth-bound alternatives, however; a few researchers have proposed creating microgravity centers in abandoned mineshafts. During the rapid drop from surface to bottom, a specialized elevator could provide several seconds of microgravity akin to that on the International Space Station. That's not long enough to grow protein crystals, but it's a start.