We have investigated the kinetics of excitation and lasing of the free radical SO by rotationally-resolved optical pumping near 250 nm with a continuously-tunable, narrow-line width KrF laser. Longitudinal photodissociation of SO2 by a 193-nm ArF excimer laser produced SO(X(3) Sigma(-)) concentrations close to 10(16) cm(-3) over a 50-cm length. Pumping of SO(B-3 Sigma(-)) by the KrF laser occurred from the v"=2 ground state cm vibrational level which was preferentially produced by photodissociation. The fraction of ground state population that could be excited to SO(B) was determined by measuring the saturation fluence for excitation as a function of buffer gas pressure and comparing with a simple model. Addition of a buffer gas increased excitation by nearly 30 times due to increased rotational mixing in the ground electronic state. Lasing was demonstrated on six new vibrational bands of fully-allowed SO(B-X) band in the region 262-315 nm. A small-signal gain coefficient of 0.11 cm(-1) and pulse energy of 11 mu J were achieved on the 270-nm SO-(B,v’=2-->X,v"=5) laser transition. A full computational rate equation model of the excitation and lasing dynamics, including collisional rotational mixing, was developed. The A(3) Pi electronic state of SO was also investigated as a possible ultraviolet energy storage laser medium. Excitation of SO(A(3) Pi,v’=5,6) near 250 nm was achieved after a time delay from photodissociation to allow for vibrational relaxation into SO(X,v"=0). Measurements of the radiative lifetime, deactivation rate, and saturation fluence, along with computation modeling, indicate that a storage laser based on the weak SO(A,v’=0-->X,v"=4) transition is not feasible with our production and excitation capabilities. Lasing on a direct-pumped single rotational transition of the SO(A,v’=5-->X,v"=1) band may be possible, but with very limited capacity to store energy.