Today while watching CBC's Power and Politics I saw a question flash by while Elizabeth May was being interviewed. Sadly, I'm not watching in high resolution, so I can only guess at the name of the questioner. I believe her name was Phyllis Brown Rouble - please correct me if you can.
She asked: “can anyone tell me how much carbon is created by one space shuttle being launched into space and what damage is done to the ozone layer”
I’m a space aficionado and I thought I’d make a quick attempt to estimate it.
First, we need a little information on the Space Shuttle. When it launched, the Space Shuttle consisted of four main visible parts: The Orbiter Vehicle itself, the External Tank, and the two Solid Rocket Boosters on each side of the External Tank.
The Solid Rocket Boosters (SRBs) are simple, cheap and reliable boosters used to get the shuttle off the ground. SRBs don’t perform as well as liquid hydrogen engines, but their job was only to get the vehicle moving. They burned ammonium perchlorate composite propellant (APCP). The actual source of fuel was aluminum because it has good energy properties and is hard to light accidentally. The fuel was held together with rubber binder. This is the carbon contained in the fuel and totalled 12.04% of the total mass of the fuel.
The Orbiter had three main engines and drew it’s fuel from the external tank. That fuel was liquid hydrogen and liquid oxygen, when the hydrogen was burned it created plain water which is considered a zero-emission fuel. No carbon whatsoever was put in the atmosphere from the liquid fuels.
Each SRB contained about 500,000 kg of fuel. Of that mass about 60,200 kg (12.04%) consisted of carbon-bearing binder. As exciting as polymer chemistry is to me, this gets crazy in a hurry. In a nutshell, we have long chains of carbon and hydrogen with some molecules of oxygen and nitrogen strategically aligned in the mix.
Very roughly, I’m going to equate 1 kg of APCP to 1 kg of gasoline. Let me stress, they are not the same, and APCP is really nasty stuff, but this is at least ballpark equivalence of carbon.
And here is where my mind gets blown.
According to Stats Can, in 2014 only in my home province of Alberta, we had gross sales totalling 6,566,200,000 litres of gasoline sold. That equates to 17,989,589 litres per day. Depending on the blend, I’m going to estimate 1 litre of gasoline is approximately 0.75 kg.
My assumption that 1 kg APCP is equivalent to 1 kg of gasoline is unrealistic and a good organic chemist will clarify far beyond what I have done here. But by the back of my envelope, Alberta sold 13,472,403 kg of gasoline per day in 2014, which is about 224 times more than the carbon produced during each Space Shuttle launch. (Please note: I chose Alberta because I live here. Quebec sells 9,212,889,000 litres per year, Ontario 16,178,215,000! Total for Canada is 43,522,454,000.
Compared with gasoline output from vehicles alone, each Space Shuttle was negligible. There were 135 Shuttle launches. We burn 200 times that much fuel each and every day in just one province of our country. I'll leave the ozone calculations to the reader unless I come back to it later in the week. Suffice it to say, I doubt it will amount to much.
Of course, the value for shuttle launches needs to be included in the calculation. Without shuttle launches we wouldn't have Earth Observation Satellites performing remote monitoring which gives us the very detail on climate change. And I'm a strong believer in all that NASA Spinoffs have given to humanity, from better materials to health and medicine to entertainment. That's a much higher rate of return on our atmospheric carbon than my teenage cruising trying to look cool.
Yes, I find the numbers mind boggling, but it's an important reminder that every attempt I make at conservation and energy reduction will have important effect on climate change. There will be no surprise to my friends -- I'll be riding my bike to work tomorrow.