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Comment: Design Life is not Expected Life (Score 3, Insightful) 136

I mean with all the technical miracles NASA pulled off on that mission, they somehow managed to underestimate the longevity of the mission by 45x.

To be fair, 90 days was not, in fact, the estimated lifetime of the mission. It was the design specification of the mission. That is, each of the subsystems was designed with the specification "design a system that will operate for a minimum of 90 (Martian) days, even under worst-case conditions."

Think of it as a 90-day warranty-- after 90 days, it wasn't expected to be dead, it was just out of warranty.

(and note that since the engineering specification was validated by testing the subsystems to either three times design life, or testing to design life under three-sigma worst-case conditions, it would have been very difficult to design for 4000 days...)

Comment: Next version, orbit [Re:What's the point ?] (Score 4, Informative) 76

by Geoffrey.landis (#49595027) Attached to: Jeff Bezos' Blue Origin Launches Its First Rocket

why Jeff Bezos is doing the same thing that SpaceX is already doing ?

They're not, New Shepard is a SUBorbital craft not an orbital one. I don't know if there are even any plans to make an orbital version...

From https://www.blueorigin.com/new...
"We continue to be big fans of the vertical takeoff, vertical landing architecture. We chose VTVL because it’s scalable to very large size. We’re already designing New Shepard’s sibling, her Very Big Brother – an orbital launch vehicle"

So: yes.

Comment: To expensive to dump spray on the ground (Score 1) 678

Desalination is a plausible solution for water for consumer use--that is, urban and suburban locations.

It is not a very plausible solution for agricultural use-- too expensive.

Actually, there are a number of issues with desalination as it presently exists. The cost of plant construction and operations puts the cost of water supply at roughly triple that of traditional methods.

Exactly. That's why it's not a plausible solution for agricultural use. If your application is to take water and spray it on the ground, yes, it needs to be cheap.

For urban and suburban use-- well, given the rents, and the cost of housing, in San Diego (not even to mention San Francisco!)-- the cost of water just isn't a factor. You could triple it and not notice.

They also depend on fossil fuels and thus contribute to greenhouse gasses. They produce brine and boron contaminants that can not easily be disposed of on either land or sea without potentially significant impact of the wildlife exposed to them.

Those are engineering problems.

Comment: It's not drinking water that's the problem here. (Score 1) 678

The 2 "crops" that are taking the water:

  • Alfalfa - going to China to feed THEIR livestock.
  • Bottled Water - Nestle's is buying municipal water at residential rates and selling it back at 100s of times the original cost.

Shut those 2 things down and water problem solved.

You are clueless.

Look, I hate Nestle and I think bottled water is stupid too, but the amount of water they bottle is trivial compared to the trillions of gallons of water shortage representing the drought. They could bottle a hundred times more water, or a thousand, and it still wouldn't make a lick of difference.

The problem is measured in trillions of gallons. It's not drinking water that's the problem here.

Comment: Power beaming [Re:Revising a previous concept] (Score 1) 167

by Geoffrey.landis (#49512497) Attached to: ISS Could Be Fitted With Lasers To Shoot Down Space Junk

> Back when I was working on lasers for power beaming

Short or long haul? Down or up?

We looked at lasers for space-to-Earth power beaming, but it's less practical than you might think-- heat rejection gets to be a serious problem. Most of the practical applications were Earth-to-space or space-to-space power beaming.

http://ieeexplore.ieee.org/xpl...
http://proceedings.spiedigital...
http://www.sciencedirect.com/s...
http://arc.aiaa.org/doi/pdf/10...
http://ntrs.nasa.gov/search.js...

Comment: Water- we dump it on the ground (Score 5, Informative) 678

Desalination is a plausible solution for water for consumer use--that is, urban and suburban locations.

It is not a very plausible solution for agricultural use-- too expensive. Do you realize that those people take the water and just dump it on the ground?

*(well, some of the suburban people just spray it on the ground, too. But they spray millions and millions of gallons on lawns. Sounds like a lot... but agriculture uses trillions of gallons.)

Water rights are complicated. Since the rule is, whoever grabbed it first owns the rights to the water, the people who own it aren't necessarily the ones who use it most responsibly. http://www.washingtonpost.com/...

Agriculture is 80% of California's water use (although only 1.5% of California's economy) The big problem is almonds. Who would have thought that such a niche foodstuff would drive agricultural water? https://www.bostonglobe.com/bu...

Trillions? Yep: http://science.nasa.gov/scienc...

Comment: Magnificent isolation [Re:Antarctica] (Score 1) 137

by Geoffrey.landis (#49477701) Attached to: Road To Mars: Solving the Isolation Problem

Not any more isolation than expeditions to Antarctica in the late 19th and early 20th century.

Wrong. Hobart is 7 days sail away. Sthn NZ is even closer.

Now. That's why I said " in the late 19th and early 20th century."

Back then, they would get frozen in, winter-over stuck in ice, and in the following summer, do the exploration.

Comment: Remember his name [Re:Alternate headline] (Score 2) 44

by Geoffrey.landis (#49467083) Attached to: Turing Manuscript Sells For $1 Million

I hate that movie. I haven't seen it, but the advertising has put me off. The man is so important, but not once during any of the ads I saw for it, did they mention his name.

There are many possible reasons to not like the movie, but this isn't one of them. The movie itself doesn't in any way hide his name.

This, for example http://www.nybooks.com/blogs/n... or this http://www.slate.com/blogs/bro...
might be reasonable excuses to not want to see the movie.

"Who alone has reason to *lie himself out* of actuality? He who *suffers* from it." -- Friedrich Nietzsche

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