Starship Asterisk*

bystander wrote:Whatever happened to Red Spot Jr? And what about Baby Red?

http://hubblesite.org/newscenter/archiv ... 7/image/a/

http://apod.nasa.gov/apod/ap090106.html

<<How hazy is Jupiter's upper atmosphere? To help find out, astronomers deployed the Hubble Space Telescope to watch Jupiter eclipse its moon Ganymede. Although Ganymede circles Jupiter once a week, it usually passes above or below the planet, so that a good eclipse occurs more rarely. Such an eclipse was captured in great visual detail in April 2007. When near Jupiter's limb, Ganymede reflects sunlight though Jupiter's upper atmosphere, allowing astronomers to search for haze by noting a slight dimming at different colors.>>

<<*HYDRAZINE* is a chemical compound with the formula N2H4. It is a colourless liquid with an ammonia-like odor and is derived from the same industrial chemistry processes that manufacture ammonia. However, hydrazine has physical properties that are more similar to those of water. Hydrazine is highly toxic and dangerously unstable, and is usually handled as aqueous solution for safety reasons.
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Hydrazine was first used as a rocket fuel during World War II for the Messerschmitt Me 163B (the first rocket-powered fighter plane), under the name B-Stoff (hydrazine hydrate). Hydrazine is also used as a low-power monopropellant for the maneuvering thrusters of spacecraft, and the Space Shuttle's Auxiliary Power Units. In addition, monopropellant hydrazine-fueled rocket engines are often used in terminal descent of spacecraft. A collection of such engines was used in both Viking program landers as well as the Phoenix lander launched in August 2007.

In all hydrazine monopropellant engines, the hydrazine is passed by a catalyst such as iridium metal supported by high-surface-area alumina (aluminium oxide) or carbon nanofibers, or more recently molybdenum nitride on alumina, which causes it to decompose into ammonia, nitrogen gas, and hydrogen gas according to the following reactions:

1. 3 N2H4 → 4 NH3 + N2
2. N2H4 → N2 + 2 H2
3. 4 NH3 + N2H4 → 3 N2 + 8 H2

These reactions are extremely exothermic (the catalyst chamber can reach 800 °C in a matter of milliseconds,) and they produce large volumes of hot gas from a small volume of liquid hydrazine, making it a fairly efficient thruster propellant with a vacuum specific impulse of about 220 seconds.
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The Italian catalyst manufacturer Acta has proposed using hydrazine as an alternative to hydrogen in fuel cells. The chief benefit of using hydrazine is that it can produce over 200 mW/cm2 more than a similar hydrogen cell without the need to use expensive platinum catalysts. As the fuel is liquid at room temperature, it can be handled and stored more easily than hydrogen. By storing the hydrazine in a tank full of a double-bonded carbon-oxygen carbonyl, the fuel reacts and forms a safe solid called hydrazone. By then flushing the tank with warm water, the liquid hydrazine hydrate is released. Hydrazine has a higher electromotive force of 1.56 V compared to 1.23 V for hydrogen. Hydrazine breaks down in the cell to form nitrogen and hydrogen which bonds with oxygen, releasing water. Hydrazine was used in fuel cells manufactured by Allis-Chalmers Corp., including some that provided electric power in space satellites in the 1960s.>>

orin stepanek wrote:I believe that Jr. is in the right hand corner at about 5 o'clock. Didn't the baby red become a snack for the giant red spot when they came together?

bystander wrote:

orin stepanek wrote:I believe that Jr. is in the right hand corner at about 5 o'clock. Didn't the baby red become a snack for the giant red spot when they came together?

I believe Jr roams the band South (below, left) of GRS. I don't think that can be Jr at 5.

It was predicted that baby red would be pulled into GRS, but that hadn't happened as of 2008 July 8

bystander wrote:

orin stepanek wrote:I believe that Jr. is in the right hand corner at about 5 o'clock. Didn't the baby red become a snack for the giant red spot when they came together?

I believe Jr roams the band South (below, left) of GRS. I don't think that can be Jr at 5.

It was predicted that baby red would be pulled into GRS, but that hadn't happened as of 2008 July 8