Photo: NASA "Clean Rooms" Brimming With Bacteria
A NASA worker samples the floor of a "clean room" for evidence of bacteria.
A recent study shows that these supposedly sterile rooms where spacecraft are assembled may be home to at least a hundred species of bacteria.
If not eliminated, the organisms could interfere with a spacecraft's instruments or contaminate other planets, experts say.
Photograph by Jet Propulsion Laboratory, California Institute of Technology