"6_2_15_11.TXT" (2175 bytes) was created on 11-29-91

NASA STATEMENT CONCERNING SPACE SHUTTLE SOLID ROCKET EXHAUST OZONE EFFECTS

The most recent scientific information available dealing with the
effects of Space Shuttle Solid Rocket inorganic chlorine releases
on the Earth's ozone is contained in a 1990 Report to Congress
from NASA's Upper Atmosphere Program.  Using a launch scenario
consisting of 9 Shuttle launches and 6 Titan IV launches per
year, model calculations examined the spread of 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% of
the total amount of halocarbons released during a year on a
global basis (0.725 kilotons released by the Shuttle, annually,
v. 300 kilotons released globally by all sources.

The report concludes that Shuttle launches at the current rate
pose little threat to the ozone layer and will have no lasting
effect on the atmosphere.  It states that the exhaust plume from
the Shuttle represents a trivial fraction of the stratosphere,
and even if ozone destruction occured within the initial plume
its global impact would be inconsequential.  Further, the
corridor of exhaust gases spreads over a lateral extent of
greater than 1000 km in a day (approximately 600 miles) and thus
no local "ozone hole" could occur above the launch site.

Concerning future Advanced Solid Rocket Motor (ASRM) static
ground testing, NASA has thoroughly studied the issue of such
testing in Southern Mississippi.  Available data and past
experience at other test and launch sites support NASA's
conclusion that ASRM testing can fully comply with current strict
regulations and permit requirements established to protect the
public and the environment.  Environmental Impact Statements have
been prepared by NASA and the Agency is developing a regional
environmental data base for air, soil, ground water, rainwater
and vegetation.  All of this information will be used to monitor
the quality of the environment and ensure that ASRM testing does
not cause any harmful effects.

August 22, 1990