Well, we all know that the COSPAR treaty has set some rules to avoid contamination of the planets by 'bacteria' from Earth ... and a similar program exists to protect Earth's environment for 'alien' bacteria which could be brought back during sample-return missions.
I'm trying to make a list of Planetary Quarantine & Planetary Sterilisation measures which were taken for spacecraft bound to Mars:

e.g. Both Viking Landers were encapsulated in an enclosed bioshield and 'cooked' ( = heat sterilization ) in an oven at NEC for 30 hours at 111.7 degrees Celsius !

Trying to find out what was done for Mars Polar Lander, Pathfinder-Sojourner, MER Spirit & Opportunity, ...

Not much...
They were made from hardware that was kept extra-clean-room clean and exposed to UV (I think) and at various times were wiped down with alcohol etc. The "bacterial load" was monitored carefully.

The working principle is that Vikings found such a hostile environment that loose bacterial spores would have a short half-life in comparison to time scales over which they might be transported to hypothetically less hostile environments.

Also note that despite soviet claims that Mars 2, 3 and 6 were sterilized, there never was any backup information to indicate they did anything more than try to keep the bacterial load low. (correct me if I'm wrong)

The ultra clean processing of the Viking Landers ( and B2 ) was because they were looking for life. No point looking for it if you take it with you.

MPF, MPL, PHX, MERA and MERB were just 'clean' to fit in with international regs. The reason for the difference is what they went to look for

Doug

Correct Doug, Pathfinder-Sojourner was cleaned to Viking standards but didnot go through the dry heat sterilization process...
I'm still wondering however what Prof PILLINGER's team did with the Beagle 2 lander?
The probe was built in a brand new aseptic assembly facility and went to environmental chambers to test the thermal properties. Several components were send to a nearby hospital for sterilization being being put into the lander... but I don't believe the complete lander underwent a separate treatment?

Every B2 Component got treated by plasma or other methods at some point as I undertstand it.

Doug

More information on Planetary protection --> COSPAR

The Beagle 2 project has met all planetary protection requirements and constraints for a Category IVa mission, which covers scenarios involving landers not employing life-detection experiments based on detection of metabolism...

I was amazed to read that for the Mars-Phobos 1988 mission a grand reception was held in the hall where the launch vehicle sat before launch

Meanwhile I'm surprised that nobody replied something about the ethical and/philosophical concerns of interplanetary exploration, especially the fact what should be done if we discover 'alien' life forms !?

Philip

Well - there's no ethical issue imho, as there will have been much cross contamination between both planets via meteorite impacts and so forth. Yes - keep spacecraft clean, but you're never going to make a sterile spacecraft, and it doesnt really matter if you take a few friends anyway.

Doug

Doug, You certainly have a point as the cross contamination by asteroids and meteorites has been going on for billions of years ...

However, the discovery of any type of 'alien' life would have a significant scientific, social, philosophical and ethical impact within the world we live in

As Benton Clark points out, the existence of natural meteoritic cross-contamination doesn't really make much different to the issues involved in the human variety -- either way. First, even if Martian meteorites are delivering Martian germs to Earth, it's a near-certainty that they don't deliver a new species to Earth more than once every few hundred thousand years -- and we have no way of knowing how much ecological trouble those species stirred up on their arrival back then.

Second, when it comes to forward contamination, the arrival of Earth germs on Mars is even less frequent -- and when humans start visiting the place regularly, they will be delivering them at a stupendously higher rate, thereby endangering possible species of Martian germs that have survived the occasional rare natural incursions by Earth microbes. It's really an extension of the massive problems produced in Earth's separate ecosystems by humanity's dramatic introduction of alien species to new regions. (Another analogy would be the fact that natural micrometeoroids turn out to constitute virtually no danger to satellites or humans -- but we've managed to contaminate Earth orbit with a gargantuan amount of artificial micrometeoroids that DO constitute a major and rapidly growing hazard.)

I beleive reasonable procautions should be taken so that we do not contaminate Mars (i.e. sterilize spacecraft etc). The problem that I have is that is seems that some take the planetary protection too far by saying that manned exploration or even containued unmanned exploration of Mars should not occur since we could not be 100% certain that contamination would not happen.

This an impossible standard which would forever prevent human exploration and or settlement of the planet. The ironic thing is that it is very unlikely we will discover life there until we have manned exploration since robots are not able to do deep, detailed, sustained field work that would be required to find it.

In my opinion, the chances of forward contamination are a near infinite impossibility, Mars is an incredibly harsh place. If contimination were possible it would already have happened from meteorites from Earth. Even assuming a very conservative figure of one meteor from Earth lands on Mars every 100,000 years, that is at least 40,000 times in the last 4 billion years that Mars may have been exposed to life from Earth, many of those in the deep past when Mars was more hospitable. If life did not take hold since then with all that exposure, careful (sterilized) exploration by mankind now posses very, very little risk.

Where manned exploration is concerned, there are serious catches in that line of reasoning. First, any manned ship will spew tremendously bigger numbers of microbes onto the Martian surface than any meteorite could possibly deliver, every time the airlock door opens -- in fact, the astronauts will be constantly leaking them out of their suits.

Second, any manned expedition -- and even any reasonably advanced unmanned one -- is going to deliberately poke around looking for life in precisely the kinds of Martian environments that are protected from the harsh surface environment, such as underground or inside rocks. These of course are also the kinds of environments which Earth meteoroid impacts are less likely to contaminate when they impact Mars -- but WE will certainly be contaminating them in the very places we're trying to study them, if we're not extremely careful.

Speaking of the devil. this just came up, same subject but on Venus.

http://news.yahoo.com/s/space/20060221/sc_...ullslifeonvenus
and
http://www.space.com/scienceastronomy/060221_venus_life.html

Preventing the Forward Contamination of Mars

Committee on Preventing the Forward Contamination of Mars, National Research Council

166 pages, 8.5 x 11, 2006

Recent spacecraft and robotic probes to Mars have yielded data that are changing our understanding significantly about the possibility of existing or past life on that planet. Coupled with advances in biology and life-detection techniques, these developments place increasing importance on the need to protect Mars from contamination by Earth-borne organisms. To help with this effort, NASA requested that the NRC examine existing planetary protection measures for Mars and recommend changes and further research to improve such measures.

This report discusses policies, requirements, and techniques to protect Mars from organisms originating on Earth that could interfere with scientific investigations. It provides recommendations on cleanliness and biological burden levels of Mars-bound spacecraft, methods to reach those levels, and research to reduce uncertainties in preventing forward contamination of Mars.

http://www.nap.edu/catalog/11381.html

Both Viking orbiters were assembled at NASA-JPL, the landers were designed, built and assembled at Martin Marietta in Denver COLORADO... but does anybody know where the Landers were dry heat sterilized ?
The landers and their aeroshell with heatshield were encapsulated in a bioshield ( contractor was Sheldahl Inc of Northfield MINNESOTA ) and were put in an oven at NEC corporation for over 30 hours...
Any idea where NEC corp was situated ?



Meanwhile I have found that large ovens were present in the KSC Spacecraft Assembly and Encapsulation buildings at Cape Canaveral ... After dry heat sterilization, propellants for descent and landing engines were fed through fill lines with biofilters to assure removal of any remaining organisms... anyway after mating to the orbiters, the complete setup was checked again for cleanliness I guess ... before going into the air conditioned Centaur shroud ...

I make no apologies for reposting this image of myself next to the Viking 2 lander at the Cape, doing my very best to be a biohazard - this was taken on or around 23 July 1975.

Bob Shaw

More here..

http://marstech.jpl.nasa.gov/content/detai...at=&TaskID=2286

We are studying spore migration from the JPL Spacecraft Assembly Facility to spacecraft, and adhesion properties of spores and spore-containing dust particles to spacecraft surfaces. Study results allow assessment of contamination probabilities and enable generation of recommended implementation approaches for bio-cleanliness and containment.

The objective of the research is to investigate the physical and chemical processes of the adhesion properties of spores and spore-associated dust particles on common spacecraft materials. The spore-material surface adhesion-force measurements generated by this study provide experimental bases for use by the contaminant transport models for forward planetary protection for MEP missions. Furthermore, this task may lead to the development of new planetary protection technologies with more-efficient cleaning and evaluation methods.