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Has there been a study addressing whether these clean rooms are completely counterproductive to their stated goal? It seems intuitive to me that if you're main

by avar 8y ago

Has there been a study addressing whether these clean rooms are completely counterproductive to their stated goal? It seems intuitive to me that if you're maintaining such a clean room the only bacteria that are going to live there are ones hardy enough to survive in those extreme conditions, you're just going to be running an accidental breeding program for bacteria likely to survive on a spacecraft. As opposed to just assembling all this stuff in a room open to the elements. It would then be completely inundated with bacteria, but none of them would have any selective advantage in being hardy. You could even feed them on purpose by spraying food for them everywhere. Then when you launch the spacecraft those fat comfortable bacteria would all instantly die because vacuum isn't an environment that's anything like what they've had to deal with, unlike the hardy ones in the clean room, and the few survivors would have no time to develop hardiness. They'd all die within hours from launch.

danieltillett 8y ago
Unfortunately that is not the way the microbes of this world (and now other worlds) work. The form that is really tough is the bacterial spore (spores are one of the lifecycle stages of some bacteria). These spores can survive in a complete vaccuum for years. The more bacteria you introduce into a system the more spores you will end up with contaminating everything. I personally doubt that this contamination is much of a problem. The planets of the solar system have been dusted in earth rocks containing bacterial spores thrown up by large asteroid strikes for billions of years.
- dom96 8y ago
  It's certainly a problem when the spacecraft's job is to detect life on other planets. If the spacecraft is contaminated with Earth microbes then it will get a false positive which is a huge problem.
  - credit_guy 8y ago
    There’s zero chance any scientist will mistake the DNA of an existing Earth microbe with alien life.
    - brilee 8y ago
      There's an open hypothesis that life may have evolved elsewhere in the universe and then brought to Earth by some means. DNA would probably have diverged by now, but who knows?
      - havemylife 8y ago
        As I understand it DNA and RNA store their information in the form of certain amino acids. If other life uses amino acids in a similar fashion they may not use the same ones that life on Earth uses. Life here uses I believe 20 different amino acids and there are several hundred known. So there's potential there I would imagine in regards to testing that hypothesis. However what mainly bothers me with it is that it doesn't explain the origin of life and why Earth couldn't have original life begin on it. Unless we can rule out that early Earth conditions would have been too inhospitable for life to start but was sufficient to sustain it I see no reason to think an extraterrestrial origin to Earth life is more likely.
        brilee 8y ago
        Agreed that the extraterrestrial origin hypothesis doesn't actually explain anything. It just merely adds a factor to the Drake equation of how likely it is for life to get started.
        a1369209993 8y ago
        > As I understand it DNA and RNA store their information in the form of certain amino acids. Actually, information is stored as RNA, with DNA as long-term storage (mnemonic: RAM nucleic acid vs disk nucleic acid) and then amino acids are assembled into proteins (hardware) based on that information. Proteins only function as information storage in pathological cases like prions. But yes, if 'alien' life used the same 20 amino acids, and especially if it has the same mapping from 64 nucleic acid triplets to 20 amino acids, then that's confirmation that it's actually just a earth microbe that escaped or was left behind.
      - learnstats2 8y ago
        You can identify statistical differences after some generations of bacterial life in the lab, as far as I recall, i.e. a very short period of time at human-scale. Therefore, yes, life would have diverged sufficiently that scientists should be able to tell the difference.
  - danieltillett 8y ago
    The reason I don't think it is a problem is that "Earth" microbes will have got to the planet long before the spacecraft.
    - colanderman 8y ago
      Uh, it kind of is a problem if that statement is the hypothesis the probe is designed to test.
      - danieltillett 8y ago
        Even if the probe was not contaminated the planets already are. We are likely to find that there is life on Mars (underground) and it looks just like life on Earth. One interesting theory is that life originated outside the Earth (say on Mars) and was transported to Earth at a later time. This theory would explain why LUCA [0] is so complex and why life appears almost as soon the Earth had liquid water [1]. 0. https://en.wikipedia.org/wiki/Last_universal_common_ancestor https://en.wikipedia.org/wiki/Last_universal_common_ancestor 1. https://en.wikipedia.org/wiki/Earliest_known_life_forms https://en.wikipedia.org/wiki/Earliest_known_life_forms
        gruez 8y ago
        >This theory would explain why LUCA [0] is so complex and why life appears almost as soon the Earth had liquid water [1]. from the wikipedia article: >LUCA should not be assumed to be the first living organism on Earth
        danieltillett 8y ago
        On the other hand it should not be assume that it is not. The complexity of LUCA is a problem since LUCA is not much less complex than a modern bacteria which is very, very complex.
        colanderman 8y ago
        Yes, but you can't test that hypothesis if the probe is contaminated. Science isn't about assuming likely things to be true.
- ss2003 8y ago
  Not to mention asteroids of interstellar origin.
pocketstar 8y ago
>Has there been a study addressing whether these clean rooms are completely counterproductive to their stated goal? What is a cleanroom's stated goal? Implying the cleanroom's only purpose is for reducing the risk of forward contamination. Spacecraft will be manufactured in a cleanroom regardless of effectiveness at stopping microbial forward contamination. Foreign Object Debris, payload and bus contamination during manufacture are the primary concerns. For example, dust or condensate on an optical payload would ruin a Discovery class mission. The stated goal of a clean room is for quality control, reducing microorganism forward contamination is a secondary.

by avar 8y ago

danieltillett 8y ago

Unfortunately that is not the way the microbes of this world (and now other worlds) work. The form that is really tough is the bacterial spore (spores are one of the lifecycle stages of some bacteria). These spores can survive in a complete vaccuum for years. The more bacteria you introduce into a system the more spores you will end up with contaminating everything. I personally doubt that this contamination is much of a problem. The planets of the solar system have been dusted in earth rocks containing bacterial spores thrown up by large asteroid strikes for billions of years.

dom96 8y ago
It's certainly a problem when the spacecraft's job is to detect life on other planets. If the spacecraft is contaminated with Earth microbes then it will get a false positive which is a huge problem.
- credit_guy 8y ago
  There’s zero chance any scientist will mistake the DNA of an existing Earth microbe with alien life.
  - brilee 8y ago
    There's an open hypothesis that life may have evolved elsewhere in the universe and then brought to Earth by some means. DNA would probably have diverged by now, but who knows?
    - havemylife 8y ago
      As I understand it DNA and RNA store their information in the form of certain amino acids. If other life uses amino acids in a similar fashion they may not use the same ones that life on Earth uses. Life here uses I believe 20 different amino acids and there are several hundred known. So there's potential there I would imagine in regards to testing that hypothesis. However what mainly bothers me with it is that it doesn't explain the origin of life and why Earth couldn't have original life begin on it. Unless we can rule out that early Earth conditions would have been too inhospitable for life to start but was sufficient to sustain it I see no reason to think an extraterrestrial origin to Earth life is more likely.
      - brilee 8y ago
        Agreed that the extraterrestrial origin hypothesis doesn't actually explain anything. It just merely adds a factor to the Drake equation of how likely it is for life to get started.
      - a1369209993 8y ago
        > As I understand it DNA and RNA store their information in the form of certain amino acids. Actually, information is stored as RNA, with DNA as long-term storage (mnemonic: RAM nucleic acid vs disk nucleic acid) and then amino acids are assembled into proteins (hardware) based on that information. Proteins only function as information storage in pathological cases like prions. But yes, if 'alien' life used the same 20 amino acids, and especially if it has the same mapping from 64 nucleic acid triplets to 20 amino acids, then that's confirmation that it's actually just a earth microbe that escaped or was left behind.
    - learnstats2 8y ago
      You can identify statistical differences after some generations of bacterial life in the lab, as far as I recall, i.e. a very short period of time at human-scale. Therefore, yes, life would have diverged sufficiently that scientists should be able to tell the difference.
- danieltillett 8y ago
  The reason I don't think it is a problem is that "Earth" microbes will have got to the planet long before the spacecraft.
  - colanderman 8y ago
    Uh, it kind of is a problem if that statement is the hypothesis the probe is designed to test.
    - danieltillett 8y ago
      Even if the probe was not contaminated the planets already are. We are likely to find that there is life on Mars (underground) and it looks just like life on Earth. One interesting theory is that life originated outside the Earth (say on Mars) and was transported to Earth at a later time. This theory would explain why LUCA [0] is so complex and why life appears almost as soon the Earth had liquid water [1]. 0. https://en.wikipedia.org/wiki/Last_universal_common_ancestor https://en.wikipedia.org/wiki/Last_universal_common_ancestor 1. https://en.wikipedia.org/wiki/Earliest_known_life_forms https://en.wikipedia.org/wiki/Earliest_known_life_forms
      - gruez 8y ago
        >This theory would explain why LUCA [0] is so complex and why life appears almost as soon the Earth had liquid water [1]. from the wikipedia article: >LUCA should not be assumed to be the first living organism on Earth
        danieltillett 8y ago
        On the other hand it should not be assume that it is not. The complexity of LUCA is a problem since LUCA is not much less complex than a modern bacteria which is very, very complex.
      - colanderman 8y ago
        Yes, but you can't test that hypothesis if the probe is contaminated. Science isn't about assuming likely things to be true.
ss2003 8y ago
Not to mention asteroids of interstellar origin.

pocketstar 8y ago

>Has there been a study addressing whether these clean rooms are completely counterproductive to their stated goal? What is a cleanroom's stated goal? Implying the cleanroom's only purpose is for reducing the risk of forward contamination. Spacecraft will be manufactured in a cleanroom regardless of effectiveness at stopping microbial forward contamination. Foreign Object Debris, payload and bus contamination during manufacture are the primary concerns. For example, dust or condensate on an optical payload would ruin a Discovery class mission. The stated goal of a clean room is for quality control, reducing microorganism forward contamination is a secondary.