Vachevsky was a female Human in Starfleet in the 23rd century. In 2288, she was in command of Starbase 99. That year, she refused the threatening demand from Marshall Galo of Binzalan Security Command, terming the marshall's ultimatum a "request" - and pointing out that the Starbase was physically incapable of acceding to it as the Binzalan Transport had left several hours earlier. (TOS comic: "A Little Adventure...")