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.