I've just found some wolves hiding in my shed
NASA's Jet Propulsion Laboratory says it has solved the mystery of a doughnut-shaped rock that appeared in front of its Opportunity Mars rover in January. Mars doughnut Before and after doughnut delivery (click to enlarge) The 1.5-inch rock, dubbed Pinnacle Island, appeared on Opportunity's cameras on January 8, and NASA …
There's a good article about it here:
Except that the one thing it doesn't mention is the actual radius of the explosion they were expecting. However, the upper limit *if all the fuel went up in one go* was something like half a kiloton, so, I'd want to be a very long way away from that.
1. Astronaut (let's assume they're a loner and happy just being the one there)
2. Oxygen (substantial)
2.5. Adequate energy generation for all of it (let's suppose nuclear for size and self-containedness).
3. Water (a small amount, so let's ignore it)
4. a unit to reclaim water from waste (not a small thing, can't ignore it)
5. Food (substantial) (or growing units to make it on the fly - pretty bloody substantial esp. if producing oxygen as well)
6. habitation for the journey (substantial) (can't fold a 'naut up small and let them freeze)
7. extra rocket size + extra fuel + probably extra rockets to get it all up to orbit (mega expensive)
8. shielding for guy/gal from external rays and one's own nuclear reactor.
9. And same again to get them back if they choose.
10. The higher cost of the transport (rocket) needed for the higher quality of the cargo (a human) - very expensive!
11. insurance against loss much higher?
12. Potential much greater negative PR if chappie/chappess leaves mortal coil in a glory of fireworks, or they just die dismally (very likely)
Given that, they could have just lifted a much larger and more sophisticated robot.
Have one of my rare downvotes - sorry.
@DougS: Oxygen's needed at about 1kg per day per adult. A crew of 10 on a 2-year round trip to Mars would only need 7300kg (no margin) without recycling, just CO2 scrubbing. And before you recycle oxygen from CO2, keep in mind that the human metabolism as produces water (lots of hydrogen in food to react with inhaled oxygen). Mir and ISS both used water electrolysis to recover oxygen from water, while carbon dioxide is mostly scrubbed and dumped overboard.
@BlueGreen: you have touched on some of the differences and challenges for sending astronauts to Mars versus nuclear robo-tanks, but those are the tip of the iceberg. A nuclear submarine has most of the features you mentioned, but it's also not nearly as expensive as a manned Mars mission. The big difference is getting all those systems (or at least their backups) to work flawlessly for several years at absolute minimum masses. "When failure's not an option, success gets really expensive."
> The big difference is getting all those systems (or at least their backups) to work flawlessly for several years at absolute minimum [...].
I was fully aware of this - see point 10.
> "When failure's not an option, success gets really expensive."
That's a great quote, like it!
> You have a very beancountery view of the world
Abso-fucking-lutely I do.
> you are only looking at direct costs and discard the indirect costs and the benefits.
So you're criticising not my muttering, hunched-over Dickensian beancounteryness, but that I missed out some beans???
"but that I missed out some beans???"
Oh, yes! Send 20 mindless rovers to mill about aimlessly on Mars and your combined mission costs (including all the support on the home planet) will add up to something close to a manned mission and for little or no return other than some pretty pictures and continuous employment of a certain number of personnel. Send a team of humans and you will get science done, useful and useable returns and much more publicity (even if your humans would sadly expire in the process).
... the rate of dust precipitation over the operational item's lifespan, as well as the risk of extraordinary 'dustings' et al, just don't warrant the cost. Remember that you can't use normal ICs, electronic circuits, and any additional mechanical or powered complexity also has a significant 'planetary transfer' cost- let alone the testing and bureaucracy cost...
Might be better that we put a robot cleaner up there someday to revive all the dusty panels, let alone clean up the donuts, turds and Chinese trash left all over the place- then again, if we ever colonise the place, maybe these things are best left well alone so the first inhabitants can feel they are well at home!
Then again, if it's a type of fungus you'd expect it to pop up elsewhere in similar shape and chemical composition, especially at places you stirred up the surface and (perhaps) some fleeting captured moisture. Not only rocks roll down hill, you know?
It's not that I don't believe NASA but to really falsify any fungus speculation, just release the definite spectrometry so other scientists can determine it to be a dry rock mass of some kind using the numbers. But just to show another weird rock shape and suppose "origination" is not really scientific sounding.
Here it is (pdf). The article contains 25 photographs of various candidates of algae, fungi, and lichens on Mars. It's tricky though, attempting science from interpreting photographs and just on some personal title. The only defence I could think of is that at least these type of life forms would be expected, if any complex biology would be there. And they would battle for available water and perhaps pop up on the track of the rover. Sadly enough nobody predicted that ahead of time. Post-priori is all too easy...
Biting the hand that feeds IT © 1998–2020