Pollution caused by space launches
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Published on: Mar 4, 2016
Transcripts - Pollution caused by space launches
Pollution caused by space launches:The Shuttle uses two engine models which use different types of fuel, thus givingdifferent exhausts.Space shuttle fuel consumed in a launch: 3.5 million poundsThere were 78 space launches worldwide in 1999, almost all much smallerthan the space shuttle.The pollution caused by space launches depends not only on the totalquantity of the fuels used, but on their chemical composition..The propellants which are decomposed into four types:1) Solid - Propellants that are a mixture of solid chemicals that burnt at a rapidrate when ignited expelling hot gasses The space shuttle uses potassiumperchlorate (KClO4) and powdered aluminum. The combustion products arepotassium chloride and aluminum oxide which is harmful for the environment2) Cryogenic - In space propellants liquid hydrogen (LH) and liquid oxygenthe resulting mixture is called FLOX which has high toxicity.They are stored in the space vehicle and pumped into the rocket engines wherethey burn to expel hot gases The combustion product is water vapor.3) Petroleum kerosene is mixed with liquid oxygen and burned in the engine Theproducts are carbon dioxide and water vapor4) Hypergolic - fuels and oxidants The combustion products depend on thechemicals used. The space shuttle The combustion products are nitrogen, watervapor and carbon dioxide.
NASAs space shuttles fires its engines for around 8.5 minutes, consuming1,000 tons of solid propellant and an additional 2,000,000 litres of liquidpropellant to lift the 100,000 kg vehicle to an altitude of 111 km and an orbitalvelocity of 30,000 km/h.With a specific energy of 31MJ per kg for aluminum and 143 MJ/kg for liquidhydrogen this means that the vehicle consumes around 5 TJ of solid propellant and15 TJ of hydrogen fuel.Reports have been made by NASA in the years 1978 and 1990. In the 1978Environmental Impact Statement , NASA the exhaust emissions of the Shuttlelaunchhydrogen chloride, chlorine, nitric oxide carbon monoxide, carbon dioxide, water,and aluminum oxide the exhaust interacts with the ozone layerand poses the threat of its depletion 57,700 kilograms of hydrogen chlorideinteracts with elements in the atmosphererelease of chlorine (The chlorine break down of ozone becomes part of acontinuous cycle of destructive reactions)