2 Questions

[_Simon_]

Hey all! So, I have 2 questions that I´ve thought about for some time now.

1. How does the liquid 02 work as fuel for the shuttles? Could it work here on earth too? (For different types of vessles that is.

2: Some time ago I was watching the movie "Knowing" with Nic Cage and I thought the whole solar flare- explosion thing was rather interesting. So my question is: Is there a real risk of such an episode described in the movie? And if it would happen, could the damages be as catastrophic and global as in the film?

//Simon

 

[BoJangles2]

In regaurds to question 2. There seems no real mechanism for that sort of event happening at that magnitude. The sun would have to become unstable in some way shape or form, maybe if the sun was side swiped by a neutron star, or it went supernova or something.

 

[kg]

Hey all! So, I have 2 questions that I´ve thought about for some time now.
1. How does the liquid 02 work as fuel for the shuttles? Could it work here on earth too?...
//Simon

Most vehicles here on earth do run on O2 (oxygen). For a rocket O2 gas is compressed into a liquid and stored in fuel tanks. Here on earth it's conveniently stored in the earths' atmospere as a gas. However it's only half of the fuel and needs to be combined with something else such as gasoline or charcole brickets as in this vidio. http://www.youtube.com/watch?v=UjPxDOEdsX8 Kurt Vonnegut in one of his novels said something like "There is something touching about a planet with 20% of its atmosphere wanting to violently combine with nearly everthing its inhabitants hold dear".
So as far as solving our energy needs O2 is everywhere and free here on earth, it's what we combine it with that's the costly part.
A rocket needs to bring O2 with it because it can't get all it needs from the atmosphere, then it leaves the atmosphere behind alltogether. A rocket also needs something else to combine it with such as H2 (Hydrogen). There are actually many different types of rocket fuels used. Liquid O2 is just one of them.

 

[crazyeddie]

Chemical rockets need two types of fuel: the propellant, such as kerosene, liquid hydrogen, gasoline, methane, etc., and the "oxidizer", the substance that must chemically combine and react with the propellant to create heat and thrust. It's interesting to note that there are other substances than oxygen can serve as "oxidizers". Liquid fluorine is one. In fact, it is a much more reactive substance than liquid oxygen, and can produce very high-performance engines. Unfortunately, it is a tricky substance to work with, and quite toxic, so while early rocket engineers experimented with it decades ago, it was largely abandoned as a fuel.

 

[drwayne]

"How does the liquid 02 work as fuel for the shuttles?"

A tip to keep you from looking foolish like I did many moons ago. Liquid O2 doesn't act as a fuel,
it acts as an oxidizer. Trust me, if you know the difference between those two, you can look really
smart at parties. Look what it's done for me!

*Sounds of laughter*

Wayne

 

[drwayne]

One of the better terms in rocketry. Mix Flourine and liquid oxygen and you get

FLOX

FLOX is somewhat easier on rocket plumbing, but still still highly dangerous. For eally really dangerous,
check out

ClF5

chloride pentaflouride

Wayne

 

[SpaceTas]

Question 1:
well answered
Note with a strong enough oxidizer nearly anything will burn as a fuel. Hydrogen peroxide was dangerous enough for me.

Question 2:

Super-flares have been observed from a few stars; mostly from young stars or M dwarf stars (=stars lower mass than Sun). I as as I know none have been observed from a single G type star like the Sun. (Stellar activity, spots, flares etc, is a research interest). Although there are several mass extinctions in the Earth's 4 billion history, all have other more plausible explanations. So a solar super-flare probably hasn't happened in the 600 million years (length of good fossil record).

Super flares are now being considered in terms of the question "How common is life?".

Also, there is the Earths magnetic field and atmosphere to protect us, being on the night side will help, and going underground or underwater would help. Since flares are short lived the radiation dose would be short lived. To wipe out Earth's eco-system would require a super-flare of such stupendous proportions to be unreal.

So I suspend disbelief and enjoy another end-of-the-world movie.

 

[_Simon_]

"How does the liquid 02 work as fuel for the shuttles?"

A tip to keep you from looking foolish like I did many moons ago. Liquid O2 doesn't act as a fuel,
it acts as an oxidizer. Trust me, if you know the difference between those two, you can look really
smart at parties. Look what it's done for me!

*Sounds of laughter*

Wayne

Well I am sorry, Wayne, if i look foolish to you. But doesnt the board say "Ask the astronomer"? So I am sorry Wayne if I came on to this board and asked a question about astronomy, when clearly I should have known all the answers myself.

 

[chris1996]

A tip to keep you from looking foolish like I did many moons ago. Liquid O2 doesn't act as a fuel,
it acts as an oxidizer. Trust me, if you know the difference between those two, you can look really
smart at parties. Look what it's done for me!
Wayne

Yea, doesn't it act as the device(don't remember the word) that keeps the rockets burning?

 

[Saiph]

_Simon_ I'm sure drwayne didn't mean to be insulting. It was meant as a joke and somewhat self-deprecating remark (he did mention he made the mistake too!)

It's often hard to get that sorta vibe through text though...and very easy to mistake it.

Good question, right forum, and I'm quite sure drwayne will agree