Before the painted ladies (Cynthia cardui), other less beautiful creatures had already ventured into space. Arabella and Anita, two notorious spiders, learned how to construct normal webs aboard Skylab, a U.S. space station launched into Earth’s orbit in 1973. Subjects in other Skylab experiments that followed—some of which can be found in the Smithsonian’s collections—included fish, monkeys, ants and bees.
In the wake of the Apollo moon shots, the Skylab program demonstrated the feasibility of spending at least several months in space. Astronauts on Skylab conducted nearly 300 distinct investigations, including 19 student experiments.
When the program was abandoned in the mid-1970s, NASA turned to shuttle flights and experiments in Spacelab research modules (which were eventually replaced by the larger SPACEHAB modules). Meanwhile, the Russian space agency extended flight durations for their cosmonauts, keeping them orbiting for more than a year at a time on the Salyut space stations and then on Mir.
Now that the International Space Station has begun 15 years of continuous habitation, many speculate that microgravity research will not only help humans travel to or even inhabit Mars but will also help them on Earth. Everything from developing advanced atomic lasers and new immunotherapies to growing three-dimensional tissues and even organs in space may eventually be possible.
The multibillion dollar station, which will ultimately weigh in at 470 tons, is expected to foster unprecedented long-term research facilities and collaborations between the participating American, Russian, European, Japanese, Canadian and Brazilian space agencies.
In February of this year, the first of six research modules—this one dubbed Destiny—was attached to the International Space Station, enabling crews to begin full-time research, with as many as 12 racks devoted to ongoing experiments.
Though much microgravity research will continue to be done on or near Earth—in bioreactors, drop towers, and special aircraft and rocket trajectories—these venues provide only short-lived seconds of near zero gravity conditions. The Space Station will increasingly provide opportunities to conduct research in these conditions that spans weeks and months, even years.
Freed from the limits of gravity, many substances behave differently, because subtle forces become unmasked. For instance, diffusion is the natural tendency of materials to spread themselves evenly in a fluid. But on Earth, this effect is tempered by the gravity-induced facts of sedimentation and buoyancy, which separate materials from one another based on their density. In space, scientists can study pure diffusion. Likewise, research in combustion science, molecular biology and fundamental physics—among other fields—can benefit greatly from a nearly gravity-free environment. That basic research, in turn, may lead to more efficient ways of creating and processing materials here on Earth—and in space.
Most of the early experiments will focus on how microgravity conditions might affect crew members on long voyages. Still, much of that research may have implications for the rest of us. It seems that the absence of gravity affects the human body in ways that mimic degenerative diseases prevalent among the elderly, including bone loss, balance problems and weakened immunity. As countermeasures are developed for astronauts, better treatments for osteoporosis and spinal cord injuries here on Earth could also result.
In many areas of microgravity research, says Eugene Trinh, director of the physical sciences division of NASA’s Office of Biological and Physical Research, "our scientific understanding is far from complete. A long-term basic research platform in space will help us make the next quantum leaps forward." In the meantime, research will continue aboard the space station and—as with the butterflies—on shuttle missions.