[meteorite-list] sterilizing rovers

[Ron Baalke]

> 
> Hi,
> I am curious as to why no one appears to have any information/comments re
> the sterilzing of interplanetary probes! 
> Surely someone on this list must have a thought on this matter!
> 
> Ron Baalke... any info?
> 

All NASA spacecraft to the planets have planetary protection requirements.
For the Mars rovers, here's the information straight from the MER press kit:


Planetary Protection Requirements

In the study of whether Mars has had environments conducive to 
life, precautions are taken against introducing microbes from Earth. 
The United States is a signatory to an international treaty that 
stipulates that exploration must be conducted in a manner that
avoids harmful contamination of celestial bodies.

The primary strategy for preventing contamination of Mars with 
Earth organisms is to be sure that the hardware intended to reach 
the planet is clean. Each Mars Exploration Rover spacecraft 
complied with requirements to carry a total of no more than 300,000
bacterial spores on any surface from which the spores could get 
into the martian environment.

Technicians assembling the spacecraft and preparing them for launch 
frequently cleaned surfaces by wiping them with an alcohol solution. 
The planetary protection team carefully sampled the surfaces and 
performed microbiology tests to demonstrate that each spacecraft 
meets requirements for biological cleanliness.  

Components tolerant of high temperature, such as the parachute and 
thermal blanketing, were heated to 110 C (230 F) or hotter to kill 
microbes. The core box of each rover, containing the main computer 
and other key electronics, is sealed and vented through 
high-efficiency filters that keep any microbes inside. Some 
smaller electronics compartments are also isolated in this manner.

Another type of precaution is to be sure that other hardware 
doesn't go to Mars accidentally.  When the Delta launch vehicle's 
third stage separated from the spacecraft, the two objects were 
traveling on nearly identical trajectories. To prevent the 
possibility of the third stage hitting Mars, that shared course 
was deliberately set so that the spacecraft would miss Mars if 
not for its first trajectory correction maneuver, about 10 days
later.