Breathing Easy on the Space Station

"In a 30 year period, there could be any number of different types of experimental facilities on board that could have any number of chemical reagents," Perry said.

Some of these chemicals are likely to be hazardous, particularly if they're allowed to combine in unforeseen ways, Perry said. Keeping these chemicals out of the air will be vital for the crew's health.

When the Space Station was first being designed, NASA engineers envisioned a centralized chemical-handling system that would manage and contain all the chemicals used for experiments. But such a system proved to be too complex.

An illustration showing the location of Node 3, where the ECLSS life support equipment will be housed. Note that the Station components in the line of sight to Node 3 are transparent in this image.

"The ability for the Station to provide generic monitoring capability to try to cover the broad spectrum of chemicals that 15 plus years of basic research will require -- obviously that's not something that the Station itself can provide," Perry said.

"It really made much greater sense that each experimental facility on board the lab module would provide its own containment of its (chemicals), essentially maintaining responsibility for the chemicals from cradle to grave," Perry said.

A safety review for each proposed experiment will determine the level of containment that the rack-mounted experiment facilities must provide. In the event of a release, the crew will seal off the contaminated module and then follow procedures for cleanup, if possible.

But careful planning and well-designed hardware should minimize the risk of this scenario, enabling the crew of the Space Station to breathe easy.