Tangential slot injection of supersonic air (M_j = 1.70) into a supersonic air freestream (M₁ = 2.93) was investigated. The model used had a slot height of 1.27 cm, which was also approximately the boundary layer thickness in the primary stream, and a thin splitter plate with a thickness of 0.052 cm. Computer controlled measurement systems were used at four streamwise stations, (x/a) = 0.25, 4, 10, 20, to determine cone static pressure, pitot pressure, and stagnation temperature. From this information profiles of M, U, and ρ̅ were also generated. Spark Schlieren and Nano-Shadowgraph pictures were taken of the flowfield. The results showed excellent repeatability and documented the development of the injected flow to beyond the region where the outer shear layer and wall boundary layer had merged. The effect of a weak shock interaction upon the shear layer was also investigated. An oblique shock, generated on the upper wall with a wedge, impinged on the shear layer. The shock wave had a nominal pressure ratio of 1.82, which did not result in separation of the wall boundary layer. The profile distortion caused by this shock/viscous layer interaction was documented. / M.S.