The Aerospace Corporation has landed a follow-on effort with NASA’s Jet
Propulsion Laboratory (JPL) to continue researching the effectiveness of
spacecraft cleaning methods used by NASA in missions to planets and moons
that could harbor life.

A second $50,000 task came to Aerospace as a result of successful research
in the same area that was completed for JPL in October 2000.

“Sterilization of spacecraft is very important for NASA missions to planets
and moons that could potentially harbor life,” explained Dr. Carl Palko, a
project engineer involved in the research.

“Outbound sterilization and cleaning is important to prevent both the
accidental contamination or infection of alien worlds with terrestrial
organisms and the accidental contamination of extraterrestrial soil or ice
samples being returned to Earth with terrestrial organisms that could be
mistaken as evidence for alien life,” Palko said.

The original effort focused on developing technologies to achieve
sterilization through a cleaning process in which all organisms were removed.
The work involved three areas: characterization of spacecraft materials,
characterization of spacecraft cleaning methods, and experimental
investigations into contaminated surfaces.

Hardy Spores

Palko said that one question JPL had was whether terrestrial bacteria might
form igloo-like structures on aluminum surfaces when the surfaces dried.
Many bacteria, he said, form spores that enable them to survive millions of
years in poor conditions, such as extreme dryness or extreme cold.

“If the igloo-like structures on the inoculated aluminum really contain
spores, it could seriously affect efforts to clean spacecraft to a level of
sterility. The preliminary results of Aerospace and JPL experiments indicate
that the domes may indeed contain spores, but further investigation is
needed,” he said.

The follow-on effort will continue research in this area and will combine
the three task areas into a single investigation to measure the effectiveness
of the cleaning method on selected spacecraft materials.

IMAGE CAPTIONS: [http://www.aero.org/news/current/sterilization.html]

[Image 1]
Suspected sporehouse cut with a focused ion beam milling system to the
dimensions of 20 micrometers by 10 micrometers, or approximately one-fifth
the width of a single human hair. (Photo by Dr. Gary Stupian)

[Image 2]
Dr. Gary Stupian, seated, takes a photo of a suspected sporehouse using a
focused ion beam milling system while team members, from left, Dr. Brent
Morgan, Dr. Carl Palko and Dr. Russell Lipeles observe. Not pictured are
team members Myriam Easton and Ken Luey. (Photo by Eric Hamburg)