Today, the NASA mission managers for STS-114 gave the go-ahead for a spacewalk on Wednesday to repair the filler material that was found to be protruding from between heat shield tiles on the bottom of the Shuttle. The trip outside is a double-first: it will be the first time that astronauts attempt an in-flight repair of the protective shielding of the orbiter, as well as the first time that astronauts venture underneath a Shuttle during a mission. And while that’s cool and all, it’s also worrisome, because nobody knows if the repair is necessary, or if the whole process will expose the Shuttle to the risk of more damage.

This whole situation is a perfect example of the more-data-isn’t-always-better problem (a problem that pops up in medical studies all the time). After the Columbia disaster, NASA committed to collecting as much data as possible about damage done to the Shuttle during the launch process. New sensors were installed in the leading edges of the Shuttle wings, Discovery took off under the watch of 107 different cameras and then underwent a new optical and laser inspection as soon as it reached orbit (which was able to see defects as small as 0.25 inches), and NASA had the orbiter do a backflip prior to mating with the International Space Station so that even more pictures could be taken of its surface. NASA has now found itself with buckets full of data it’s never had before… and has never had the chance to understand before. NASA has stated that prior rules deemed safe any gap fillers sticking out a quarter of an inch or less, but that information came from inspection of the Shuttles after landing, and after the burning heat of reentry had a chance to work its effect on anything protruding beyond the protective surface of the heat tiles — so nobody knows how to interpret the new findings.

Only NASA can go through the process of deciding the risks and benefits of traveling under the Shuttle to attempt a repair; the rest of us are just armchair astronauts. In the end, though, we all have to hope that putting a microscope to the surface of the Shuttle doesn’t send people on risky missions to fix situations that aren’t problems, but rather are new discoveries of phenomena that have been happening since Columbia roared into the sky back in 1981.