New Mars Forums

The only question that I could raise would be whether we have actually explored the red planet enough to really say with any certainty that there is not now nor has there ever been life there.  You contend that we do know enough to say with a reasonable degree of certainty that life does not exist on Mars.  However, particularly with regards to past life, I don't believe that evidence is yet present.  In my opinion, it is entirely feasible that life could have been transferred from Earth to Mars, or established on Mars itself, and then as the climate fell into disequilibrium and geological heat sources cooled was simply unable to replicate itself faster than the environment destroyed it.  It is possible that the introduction of life is what caused this disequilibrium to occur in the first place.  While life maintains internal homeostasis, there is nothing impossible or even uncommon about an organism entering an environment and through its growth making it unlivable.  I do not claim that there is evidence for this but I do believe that it is plausible and cannot be ruled out based on the available evidence.

More importantly, however, you raise a largely unconsidered solution to the Fermi Paradox:  Why does it look like the universe is devoid of intelligent life?  Because it is.

Curiosity continues to be held hostage by geologist. They have done soil samples and we should live long enough to get the results.

This is "a rock."

http://farm9.staticflickr.com/8336/8119653269_022fe1fe6e.jpg
MSL Curiosity on Mars. Sol 76 by txNotAlien, on Flickr

mars-images wrote:

Looks like someone tried to roll a joint.

Curiosity sol 64

https://lh5.googleusercontent.com/-zkaa … w-fY/1.jpg

Looks like something you find on the seashore on Earth...

I was very pleased to see a successful Dragon flight in spite of an engine out.  In the absence of details,  I do not understand the NASA safety rule forbidding second stage restart after a first stage problem.  That caused the loss of the piggyback Orbcomm satellite,  not anything to do with the Falcon-9.  Bureaucracies,  bah,  humbug!  That's why Spacex is looking for its own launch site.  I hope they pick south Texas. 

On the other hand,  Spacex will have to get to the bottom of the engine out,  even if NASA were not breathing down their neck.  Something leaked somewhere upstream of the throat,  that's how you get a pressure drop.  Leaks get catastrophic in a tiny fraction of a second,  that's why you need an automatic way to detect them and shut down,  at way-faster-than-human speed.  Looks like the controls on the Falcon-9 do exactly that.  Bravo and kudos to Spacex for getting the safety/failsafe things right!

Leaks ahead of the throat show more pressure loss than thrust loss,  at least initially on the transient while the hole is still small.  Leaks downstream of the throat will show as thrust loss with no chamber pressure loss at all.  You'll have to be monitoring thrust,  as well as pressure,  to detect leaks in the bell downstream of the throat.  I would hope they know to do that.  I would guess they are doing it,  based on how well they have done the rest. 

Leaks in either place cause errant hot gas plumes and shedding debris that very quickly damage adjacent engines or other structures.  You have to worry about both phenomena. 

BTW,  what I said about engine and nozzle leaks applies to all rockets,  not just liquids.  Solids and hybrids,  too. 

GW

I agree with you louis. The public votes on the people who decide their funding.

The only problem I can see is the data transfer rate. But then again, I don't know.

-Koeng

I suspect Luna is a lot easier to monetise, as it were, than Mars. There's a lot of ways that I can think of making money from Luna that don't actually require anyone going there in person - returning Lunar rocks, to be polished for jewelry; renting out rover time; the aforementioned memorial field for ashes... Perhaps enough revenue could be raised to bootstrap the next level of actually sending people there and establishing a base, which would allow for tourism and make volatile mining easier (people could actually fix the machines when they break down).

louis wrote:

If you haven't got the soil, it's more complicated: you have to make the soil.

You have soil. It's just different. And making Mars soil arable is a lot simpler than making hydroponic nutrient solutions. As I said: add water, carbonated water, and nitrogen fertilizer. That's it.

The point about dust storms (which can continue for 90 days) is that the reduced light levels will mean the crops die. You can't build a thriving community on that basis. At the very least, whether you have soil or nutrient solution, you will need artificial light.

Artificial light must be a backup only. Exclusively for those dust storms. Every other life support system is dependant on power, so your power supply becomes a single point of failure. If power fails, you can't breathe. A greenhouse with ambient light is the only means of life support with power failure. Biosphere 2 found a biosystem even as large as their huge greenhouse was not stable, after a single year they had to add fresh air. But a Mars greenhouse could provide life support for weeks, or even a couple months while technicians repair the power system. Just ensure power doesn't fail at the same time as a dust storm.

Power balance: use surplus power for in-situ resource utilization, such as smelting iron, smelting aluminum, making glass, making cement, etc. During a dust storm, all power will have to go to the greenhouse, other life support systems, communications and science. Using artificial light in the greenhouse will be at the expense of ISRU.