Freethought & Rationalism Archive

Mageth · 02-06-2003, 10:22 AM

In light of some of the flak that NASA has been receiving as of late, I thought I'd mention the Helios prototype as an example of a fascinating project NASA's been working on that has the potential to provide significant long-term benefits, for example a cheaper alternative to orbital satellites (referred to as "atmospheric satellites).

Dryden Flight Research Center page on Helios

Click here for a cool picture (there are more images, and even some movies, on the Dryden site).

Shake · 02-11-2003, 10:59 AM

This is certainly some interesting and exciting technology at work! I'm very interested in how such research could spin off to more widely used technologies, like automotive fuel cells.

A question though: can someone explain how this:

Quote:

Long flight times require a very light weight energy storage system based on a fuel cell concept. Using a device called an electrolyzer, this system stores excess electrical energy generated by the solar cells to disassociate water molecules. Oxygen and hydrogen gases are accumulated in separate tanks. At night, when the solar cells stop producing electricity, the process is reversed. The oxygen and hydrogen gases are fed into a device called a fuel cell which produces water and electricity. The electricity is used to power the Helios Prototype until the next morning , when the cycle starts all over again.

works? By that, I mean I understand the process, but where do they get the water from? Is it atmospheric water vapor?

Abacus · 02-11-2003, 11:10 AM

Quote:

Originally posted by Shake
A question though: can someone explain how this:works? By that, I mean I understand the process, but where do they get the water from? Is it atmospheric water vapor?

Couldn't they use tap water and continuously recycle it?

Corona688 · 02-11-2003, 11:11 AM

Well, since fuel cells(generaly) do 2H2 + O2 -> 2H20, and electrolosys does 2H20 -> 2H2 + O2, my guess is they can keep using the same water over and over if they're careful not to contaminate it.

02-06-2003, 10:22 AM	#1
Mageth Contributor Join Date: Jul 2001 Location: Deep in the heart of mother-lovin' Texas Posts: 29,689	Helios UAV: something cool from NASA In light of some of the flak that NASA has been receiving as of late, I thought I'd mention the Helios prototype as an example of a fascinating project NASA's been working on that has the potential to provide significant long-term benefits, for example a cheaper alternative to orbital satellites (referred to as "atmospheric satellites). Dryden Flight Research Center page on Helios Click here for a cool picture (there are more images, and even some movies, on the Dryden site).

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02-11-2003, 11:11 AM	#4
Corona688 Veteran Member Join Date: Feb 2001 Location: Hiding from Julian ;) Posts: 5,368	Well, since fuel cells(generaly) do 2H2 + O2 -> 2H20, and electrolosys does 2H20 -> 2H2 + O2, my guess is they can keep using the same water over and over if they're careful not to contaminate it.

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