79 Impact of the space shuttle on the ozone layer
Description
This article is from the Space FAQ, by Jon Leech leech@cs.unc.edu and Mark Bradford tla@surly.org with numerous contributions by others.
79 Impact of the space shuttle on the ozone layer
From time to time, claims are made that chemicals released from
the Space Shuttle's Solid Rocket Boosters (SRBs) are responsible
for a significant amount of damage to the ozone layer. Studies
indicate that they in reality have only a minute impact, both in
absolute terms and relative to other chemical sources. The
remainder of this item is a response from the author of the quoted
study, Charles Jackman.
The atmospheric modelling study of the space shuttle effects on the
stratosphere involved three independent theoretical groups, and was
organized by Dr. Michael Prather, NASA/Goddard Institute for Space
Studies. The three groups involved Michael Prather and Maria Garcia
(NASA/GISS), Charlie Jackman and Anne Douglass (NASA/Goddard Space
Flight Center), and Malcolm Ko and Dak Sze (Atmospheric and
Environmental Research, Inc.). The effort was to look at the effects
of the space shuttle and Titan rockets on the stratosphere.
The following are the estimated sources of stratospheric chlorine:
Industrial sources: 300,000,000 kilograms/year
Natural sources: 75,000,000 kilograms/year
Shuttle sources: 725,000 kilograms/year
The shuttle source assumes 9 space shuttles and 6 Titan rockets are
launched yearly. Thus the launches would add less than 0.25% to the
total stratospheric chlorine sources.
The effect on ozone is minimal: global yearly average total ozone would
be decreased by 0.0065%. This is much less than total ozone variability
associated with volcanic activity and solar flares.
The influence of human-made chlorine products on ozone is computed
by atmospheric model calculations to be a 1% decrease in globally
averaged ozone between 1980 and 1990. The influence of the space shuttle and
Titan rockets on the stratosphere is negligible. The launch
schedule of the Space Shuttle and Titan rockets would need to be
increased by over a factor of a hundred in order to have about
the same effect on ozone as our increases in industrial halocarbons
do at the present time.
Theoretical results of this study have been published in "The Space
Shuttle's Impact on the Stratosphere", MJ Prather, MM Garcia, AR
Douglass, CH Jackman, M.K.W. Ko and N.D. Sze, Journal of Geophysical
Research, 95, 18583-18590, 1990.
Charles Jackman, Atmospheric Chemistry and Dynamics Branch,
Code 916, NASA/Goddard Space Flight Center,
Greenbelt, MD 20771
Also see "Chemical Rockets and the Environment", A McDonald, R Bennett,
J Hinshaw, and M Barnes, Aerospace America, May 1991.
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