Future Astronauts Must Deal With Toxic Chemicals In Martian Soil 117
Thorfinn.au sends this quote from Space.com:
"The pervading carpet of perchlorate chemicals found on Mars may boost the chances that microbial life exists on the Red Planet — but perchlorates are also perilous to the health of future crews destined to explore that way-off world. Perchlorates are reactive chemicals first detected in arctic Martian soil by NASA's Phoenix lander that plopped down on Mars over five years ago in May 2008. It is likely both of NASA's Viking Mars landers in 1976 measured signatures of perchlorates, in the form of chlorinated hydrocarbons. Other U.S. Mars robots — the Sojourner, Spirit and Opportunity — detected elemental chlorine. Moreover, orbital measurements taken by the Mars Odyssey spacecraft show that chlorine is globally distributed. [Phoenix principal investigator Peter Smith] said microbes on Earth use perchlorate for an energy source. They actually live off highly oxidized chlorine, and in reducing the chlorine down to chloride, they use the energy in that transaction to power themselves. In fact, when there's too much perchlorate in drinking water, microbes are used to clean it up, he said. Furthermore, seasonal flow features seen on Mars may be caused by high concentrations of the brines of perchlorate, which has a strong attraction to water and can drastically lower its freezing point, Smith told SPACE.com. The high levels of perchlorate found on Mars would be toxic to humans, Smith said."
Read the signs (Score:3, Interesting)
It's an energy and useful material source:
...perchlorate is used within the pyrotechnics industry, and ammonium perchlorate is also a component of solid rocket fuel....
researchers propose a biochemical approach for the removal of perchlorate from Martian soil that would not only be energetically cheap and environmentally friendly, but could also be used to obtain oxygen both for human consumption and to fuel surface operations.
It lowers water freezing point:
Furthermore, seasonal flow features seen on Mars may be caused by high concentrations of the brines of perchlorate, which has a strong attraction to water and can drastically lower its freezing point, Smith told SPACE.com
and it's a poison for humans:
"It's bad for astronauts because it is toxic for humans, as it interferes with the thyroid," he said.
So read these signs, Mars is even more difficult for human exploration than previously understood, but it provides potential energy source for machines to fuel themselves.
This only means that if we are going to do something in the near future, it's going to be more robots powered by perchlorate chemical reactions.
Re:Anyway (Score:5, Interesting)
Even if you want to introduce microbes, you'll need to find some that are useful under Martian conditions.
They are tough little bastards, so finding microbes that aren't killed will probably be easy enough; but finding ones that are metabolically active(rather than just capable of dormant endurance) could be trickier. Bacteria are pretty good at shriveling up and shrugging off downright alarming conditions(unprotected exposure to the vacuum of space, ionizing radiation, freezing, etc.); but they can't exactly shiver to keep themselves warm.
On the plus side, if you are planning on humans, you'll have to have a climate-controlled habitube setup anyway, so you could presumably use off-the-shelf perchlorate cleaner bacteria in 'scrubber' units that treat contaminated materials before they are introduced into the human support environment.
Re:Safe workplace (Score:5, Interesting)
When was the last time an astronaut would survive exposure to anything outside Earth's atmosphere. Keep those helmets on kids, regulations and all that.
I imagine that the problem is astronauts in suits tracking dust back into the airlock and then, once unsuited, breathing in the perchlorate goodness, possibly with a side of delicious silicosis...
I remember reading about a scheme where the 'suit' would remain permanently outside the habitat, with a docking hatch in the rear, specifically to avoid this sort of contamination.
This is good. (Score:4, Interesting)
Perchlorate at 1% concentrations?
Perchlorates are very easy to turn into rocket fuel or oxygen. Two things potentially of much use on mars. I expect the processing would need too much bulky equipment, time and manual labor to be practical on a plant-flag-and-leave mission, but a long-term sustainable base could certainly put it to good use.
Mars, the solid rocket fuel factory (Score:5, Interesting)
Ammonium Perchlorate is a very powerful oxidizer - and has been extensively used to make solid rocket propellant
Since Mars has so much perchlorates around why don't we turn Mars into planet-wide base for building solid rocket fuel ??
Re:Anyway (Score:2, Interesting)
Perchlorate is an oxidising agent. You need something that bacteria can oxidise - otherwise they can not live and thrive. The same is valid for using the stuff as rocket fuel. You need something else to oxidise - only then perchlorate is actually useful. Oh, and by the way: Wenn chemist need a nice non-reactive salt - perchlorate does just fine (at least in aqueous environments) -- it's not the best microbial food in the world!