STS-117: The Inside Guide
What’s going on beside the spacewalks.
Astronaut Sunita Williams—her NASA colleagues call her “Sunny”—spent a few hours swabbing down the International Space Station before space shuttle Atlantis and its crew of seven arrived on Sunday for a week-long stay. It isn’t that she’s a neat freak, although astronauts on the station, where Williams has been living since December, do like to tidy up for visitors. In this case, the ISS flight engineer is running an experiment.
Research on the shuttle and station has taken a back seat to engineering lately, as NASA enters the final phase of assembling the orbiting laboratory. The main purpose of this 12-day STS-117 mission is to install a new set of power-generating solar arrays. Still, there always are secondary tasks and small experiments going on behind the scenes. Here are a few of the less celebrated activities happening inside the shuttle/station complex this month:
Swabbing the deck: Williams’ cleanup is part of an experiment called SWAB (Surface, Water and Air Biocharacterization) sponsored by the Johnson Space Center. Past experience has shown that nasty microbes grow even in the climate-controlled confines of a space station. Astronauts on the Russian Mir station in the 1990s were chagrined to discover bacteria and fungi growing behind equipment panels where water had condensed into floating blobs. The International Space Station is cleaner than Mir or the shuttle, but certain areas still get funky despite regular crew cleanups: the galley, near the shower, and wherever the astronauts happen to toss their sweaty clothes after exercising. Atlantis will bring back swab samples collected from different areas on the station by Williams and her crewmates over the past several months. The samples will be analyzed on the ground to give researchers a better idea of what germs might infest a spaceship on a long journey to Mars.
Germ spotter: Currently, the station astronauts use petri dishes to culture and identify microorganisms found on board, a process that takes days. The LOCAD (Lab-On-A-Chip Application Development—Portable Test System) is meant to speed up the job and provide quicker warnings about any potential health threats. Borrowing a technology used on the ground, researchers from Charles River Endosafe in Charleston, South Carolina, and NASA’s Marshall Space Center in Alabama came up with a handheld gadget that in 15 minutes can identify germs swabbed from station instrument panels and other surfaces. The active fluid in LOCAD is an enzyme found in the blood of horseshoe crabs, which reacts in the presence of bacteria. The LOCAD tests have worked so well that NASA plans to leave the device onboard the station.
Break it down: Back in the 1990s, NASA researcher Lakshmi Putcha surveyed astronauts about their use of medicines in orbit and discovered something curious. About eight percent of the treatments given to shuttle crew members—from antibiotics to drugs for space sickness, backaches and other ailments, didn’t work in space. Subsequent examination of the medicines flown on several shuttle flights showed that certain drugs, like the antibiotic Augmentin, were indeed degrading chemically during spaceflight.
One possibility is that the medicines were losing their effectiveness due to radiation. On Earth, drugs are stored in brown tinted bottles to block ultraviolet light that could break down their ingredients. In space, the background radiation is far worse. For an experiment called Stability (Stability of Pharmacotherapeutic and Nutritional Compounds) Putcha sent up packages of medicines and food (whose vitamins also can break down due to radiation) to see how they were affected by a six-month stay on the station. Atlantis will bring the samples back for analysis. If drugs don’t work as advertised after long-term storage in space, and if foods don’t deliver the nutrients they’re supposed to, doctors need to know about it before packing these supplies on a three-year round-trip to Mars.
Watch that diet: Astronauts on short shuttle flights eat meals packed with their nutritional health and personal preferences in mind. As often as not, they end up swapping foods with their crewmates or otherwise straying from their carefully planned diets. No such laxness for Williams, who’s been participating in the most comprehensive study of astronaut nutrition ever conducted. Not only has she been keeping track of everything she eats, she’s been taking periodic blood and urine samples and putting them in an onboard freezer for return to Earth. Crewmate Michael Lopez-Alegria, who left the station in April after spending a U.S.-record 215 days in orbit, also did the nutrition study, and NASA doctors plan to collect similar information from a dozen or so station astronauts. Williams, who in April “ran” the Boston marathon on a treadmill while circling the Earth, will head home with Atlantis on June 19. No doubt she looks forward to going back to eating without some NASA doctor inspecting every bite.
For a list of experiments currently on the space station,click here.
To read our “inside guide” to the last shuttle mission,click here.