Estimate of the contribution of the space shuttle effluent to the natural stratospheric aerosol

During the period 1979–1990, the National Aeronautics and Space Administration is planning some 580 (or approximately one per week) space shuttle flights. Each of these flight configurations will include two large solid fuel rocket boosters (SRB) which will emit aluminum oxide (Al2O3) particles as exhaust products. We estimate the equilibrium distribution of such particles in the stratosphere and suggest that the shuttle contribution of very small particles, r∼0.01 µm may be nonnegligible.