Covariant quantization of superstrings based on Becchi-Rouet-Stora invariance

A manifestly covariant quantization of the superstring is presented in the Neveu-Schwarz-Ramond formalism on the basis of the Becchi-Rouet-Stora (BRS) invariance principle. The critical dimension D=10 and the correct Regge intercept are shown to follow from the requirement of the nilpotency $Q_B$${\mathrm{}}^2$=0 of the BRS charge. A modified form of the subsidiary condition of Kugo and Ojima $Q_B$‖phys〉=0 to define the physical subspace is sufficient to demonstrate the no-ghost theorem.