Mars Curiosity Flight away

[CraigS]

Originally Posted by Robert9

Are you saying that you feel its worth while polluting an unknown environment with plutonium?

No.
I might say that I feel the minimal risk of radioactive contamination on Mars, is far outweighed by the potential gains in returned knowledge.
The MMRTG has been engineered to minimise this risk.

Originally Posted by Robert9

If there are life forms on Mars, this, undoubtedly, will tell us what we can expect back here on Earth.

Really ?
How do you know this for certain ?

Originally Posted by Robert9

But can we measure anything without changing it - Heisenberg ? Surely precautions must be taken to limit the changes. We do try not to carry bacteria. Perhaps we should be limiting other forms of pollution, eg radioactivity, even if it means restricting our exploratory capabilities.

Sure. It has already been considered ... the MMRTG engineering has minimised the risk to the extent that the option of restricting exploratory projects, is unnecessary.

I look forward to your response to my original question:

Originally Posted by CraigS

With this perspective, is it now justified ?

Cheers

[Robert9 (Robert)]

Craig,

We can never know anything for certain. However, we are aware that radiation has an effect on life as we know it. IMO, if we artificially radiate any existing life-form on Mars, or anywhere else for that matter, chances are that it will be effected.

Yes, we can minimize risk, but the possibility of poluting with somethin that will last a long, long time, to me, is a very great risk to the threatened environment.

Notwithstanding all my arguments, I am certainly not averse to the exploration. I am just concerned that we might do irreversible damage to the place we want to study that will effect our eventual findings, rendering them, possibly, meaningless. This particulalrly, as I said before, in regard to possible extant life forms.

Robert

[CraigS]

No problems, Robert. I understand you perspective.

I think we live with accepting risks every day of our lives. The quest for knowledge is not without risk.

There are probably more Plutonium-238 bearing RTGs lying around garbage dumps in Russia that probably represent a greater risk to life overall, than Curiosity's. (I mean … we at least already know life exists here. )

In the earlier times, several spacecraft RTGs have crashed back onto Earth and some people were exposed to the alpha radiation emitted by the damaged units. Shielding and distributed isotope design specs have improved a lot since those days.

If a unit were to somehow partially leak radiation in situ on Mars during the operational life-time of the probe, the radiation detections on board Curiosity would probably detect it (and measure the levels, thereby allowing this to be subtracted from the assessment of the 'habitability').

One of the quests of Curiosity is to measure the amount of incident radiation on the surface. This is likely to represent far more risk to extant life, (if it exists), than the MMRTG also, because incident radiation contains a broader spectral mix of different types of 'nastier-to-life' radiation than MMRTG's alpha type. If life exists on Mars, then it has had to survive in a radiation-bathed environment for a long time.

Overall, I think our pathological, instinctive fears of 'radiation' may play on our emotional side when it comes this issue, whereas the rational side has got it all well-scouted (IMO).

Cheers

[CraigS]

I've just gotta add this link to this thread ... it contains a short video on how the MMRTG was assembled by the very people who did it ! (Scroll down to the bottom of the page).

Once constructed, they are confident enough about its safety that you can see them manoeveuring the unit around whilst wearing nothing more than t-shirts ! Now, that's a pretty relaxed outlook while one is standing a couple of feet away from a nuclear power source !

This is what I mean about how our instinctive fears about the nuclear power supplies are very likely to be quite irrationally based. It would seem the INL folk might see it all this way, eh ?

Cheers

[Robert9 (Robert)]

Originally Posted by CraigS

This is what I mean about how our instinctive fears about the nuclear power supplies are very likely to be quite irrationally based. It would seem the INL folk might see it all this way, eh ?

Cheers

I can only add that the Japanese were very confident about the safety of their nuclear reactors until the unexpected happened.
One must always expect the unexpected even if it is totally irrational and motivated solely by our emotions.

Robert