11/1/93: NASA STATEMENT CONCERNING SPACE SHUTTLE SRB EXHAUST EFFECTS ON OZONE

Using a launch scenario of nine Shuttle launches and six Titan IV launches per year, model calculations examined the spread of the exhaust plume from a single Shuttle launch and then followed the steady-state buildup of chlorine from several years of launches.

The report found that the chlorine released annually in the stratosphere by the projected Shuttle launches is about 0.25 percent of the total amount of halocarbons released during a year on a global basis.

The report concludes that Space Shuttle launches at the current rate pose no significant threat to the ozone layer and will have no lasting effect on the atmosphere. The exhaust plume from the Shuttle represents a trivial fraction of the stratosphere, and even if ozone destruction occurred within the initial plume, its global impact would be inconsequential. Further, the corridor of exhaust gases spreads over a lateral extent of greater than 1,000 kilometers in a day (approximately 600 miles) and thus no local "ozone hole" could occur above the launch site.

Images taken by the Total Ozone Mapping Spectrometer (TOMS) aboard NASA's Nimbus-7 satellite at different points following shuttle launches show no measurable ozone decrease.

Notice that was assuming NINE launches a year- we are WAY below that...