The amount it pollutes is likely negligible.
“One shuttle launch does more Ozone Layer damage than if you had dumped every R-12 air conditioner on the planet.”
NOT EVEN CLOSE!
http://www.aerospaceweb.org/question/spacecraft/q0298a.shtml
” Large amounts of chlorine high in the stratosphere attack ozone and cause it to break down. Earth’s ozone layer absorbs ultraviolet radiation from the Sun and protects life on the surface from this cancer-causing radiation. However, studies have shown that the amount of chlorine produced by the Space Shuttle and other rockets using similar solid propellants is actually quite small and has a miniscule effect on the ozone layer.
Independent atmospheric modeling studies performed by NASA and private research firms in 1990 and 1991 indicated that the vast majority of chlorine present in the stratosphere is produced by industrial or natural sources. In an average year, industry generates an estimated 300 million kilograms of stratospheric chlorine while natural sources like volcanoes produce about 75 million kilograms. Assuming nine Space Shuttle launches and six launches of Titan rockets per year results in a total of 725,000 kilograms of chlorine released into the upper atmosphere. The actual launch rate of the Shuttle has only been this high once, in 1985, and is generally much lower with an historic average of less than five launches per year. “