Once a week!?! (APOD 16 Mar 2008)

[alexpirie]

How much grunge/blast-off?

Just spent a day in a toxics workshop and maybe hypersensitive, but that looks like a pretty big carbon footprint left behind when those rockets leap up. OK, the Hubble, not OK every rich guy in the neighborhood who wants bragging rights on how much those of us left behind have to inhale. this gives a new meaning to "eat my dust (and other substances)!"

Anyone have accurate information and just what the leave behinds are?

Is there a sustainable grunge@blastoff per week/ego (national and personal) gratification ratio?

[Case]

It takes quite a lot of (presumably fossil fuel) power to fill those tanks with oxygen and hydrogen, but the launch is clean: oxygen and hydrogen produce water (vapor).

[auroradude]

The main engines (liquid hydrogen and liquid oxygen) account for only 17% of the thrust at liftoff. The other 83% is provided by the solid rocket boosters. Each external booster contains 1,100,000 pounds of propellent.

The propellant mixture in each SRB motor consists of ammonium perchlorate (oxidizer, 69.6% by weight), aluminum (fuel, 16%), iron oxide (a catalyst, 0.4%), a polymer (such as PBAN or HTPB, a binder that holds the mixture together, also acting as secondary fuel, 12.04%), and an epoxy curing agent (1.96%). This propellant is commonly referred to as Ammonium Perchlorate Composite Propellant, or simply APCP.

It's over two million pounds of a little more than just water but it sure looks cool when it burns!

[Qev]

The exhaust of the SRBs is a bit nastier than that of the shuttle main engines. Using ammonium perchlorate and aluminum, the primary exhaust components end up being aluminum oxide (pretty harmless) and hydrogen chloride (which forms hydrochloric acid in water).

I've also encountered mention that the SRBs use potassium perchlorate, which would replace the hydrogen chloride exhaust with potassium chloride, a much less unpleasant byproduct. But I'm not sure which is actually used.

[NoelC]

It takes quite a lot of (presumably fossil fuel) power to fill those tanks with oxygen and hydrogen, but the launch is clean: oxygen and hydrogen produce water (vapor).

Baloney. What about all that aluminum being burned in the solid fuel boosters?!?

Aluminum has been postulated to be involved with Alzheimers.

Now what was I writing???...

-Noel

[auroradude]

I'm not quite sure what the polymers (PBAN orHTPB) that make up about 12% of the mixture are but I think perhaps they are rubber. Maybe kinda like burning tires?

[Qev]

Baloney. What about all that aluminum being burned in the solid fuel boosters?!?

Aluminum has been postulated to be involved with Alzheimers.

Now what was I writing???...

-Noel

Aluminum oxide is pretty harmless, and I'm pretty certain the whole aluminum-Alzheimers link was debunked.

Still, 190 tonnes of hydrochloric acid and 300 tonnes of aluminum oxide dust isn't exactly being environmentally friendly. There's also relatively small quantities of aluminum chloride, aluminum sulfide, nitrogen oxides, carbon dioxide, and other fun things from the organic compounds used as a binding agent and secondary fuel.

Overall, though, I wouldn't call the shuttle terribly polluting. There's only two of them, and they don't launch all that often.

[iamlucky13]

Aluminum oxide is pretty darn close to harmless. It's a good thing too. It's a major component of dirt. I believe the postulated Alzheimers factor, which is far from confirmed, is from either straight aluminum or some other not fully oxidized form.

Hydrochloric acid, the acid formed by dissociation of hydrogen chloride in water, is the stuff in your stomach. It also dilutes quite readily. It's also commonly used in industry. Dow alone produces over 2 million tons per year.

The recommended disposal method for household HCl is to dilute it with water to a pH of 5-9 (better than some hard water) and pour it down the drain).

I'm not sure what less byproducts there are other than iron-oxide (rust), and no doubt some CO2 from the polymer binder.

And of course, water vapor has already been discussed.

By the way Qev, there's three shuttles: Endeavor (up now), Discovery, and Atlantis. There's typically 3-6 launches per year.

[Qev]

By the way Qev, there's three shuttles: Endeavor (up now), Discovery, and Atlantis. There's typically 3-6 launches per year.

Whoops! I'm not sure how I managed to count that as 'two'.

[BMAONE23]

HOPEFULLY,
Endeavor returns safely and there are still three after the end of the mission.

[johnlary2403]

According to my research Aluminium is the most widely used non-ferrous metal. Therefore, you can create or discover new things by this.


____________________
blanchard grinding

[aristarchusinexile]

Regardless of what else rocket launches and jet aircraft emit into the atmosphere, the heat pollution must be enormous.

[Qev]

Regardless of what else rocket launches and jet aircraft emit into the atmosphere, the heat pollution must be enormous.

Nah, not so much really. I mean, the total world energy consumption for 2008 is estimated to be around 500 exajoules (less, if you ignore renewable energy, which is effectively just solar power), which is less than 1/10000th of the yearly solar input. And shuttle launches are (for now at least) very infrequent short duration events so I can't see them having any huge impact, even locally (unlike, for example, a nuclear plant's use of a local body of water for cooling).

As for jets, I imagine their tendency to create cloud cover with their exhaust has a vastly greater impact than the heat produced by their engines; based on energy consumption in the United States (probably a faulty assumption, but it's what I could find), air transport uses only about 3.5% of the total energy consumed, while it's been estimated that in air-traffic-heavy areas, cloud cover has increased up to 20%.

[aristarchusinexile]

Regardless of what else rocket launches and jet aircraft emit into the atmosphere, the heat pollution must be enormous.

Nah, not so much really. I mean, the total world energy consumption for 2008 is estimated to be around 500 exajoules (less, if you ignore renewable energy, which is effectively just solar power), which is less than 1/10000th of the yearly solar input. And shuttle launches are (for now at least) very infrequent short duration events so I can't see them having any huge impact, even locally (unlike, for example, a nuclear plant's use of a local body of water for cooling).

As for jets, I imagine their tendency to create cloud cover with their exhaust has a vastly greater impact than the heat produced by their engines; based on energy consumption in the United States (probably a faulty assumption, but it's what I could find), air transport uses only about 3.5% of the total energy consumed, while it's been estimated that in air-traffic-heavy areas, cloud cover has increased up to 20%.

All I know is I was watching the big jets take off out of Toronto and I seem to recall there was one every 30 seconds .. and that's not including landings. That's only one airport in one smaller city in a world jam packed with cities and multi jam packed with airports. You're right about nuclear plants though .. wowzoe .. the rivers of heated water flowing out of those things!