The U.S.S. Kelvin (NCC-0514) was based on a single-nacelle Federation starship design that was the workhorse of Starfleet in 2233. The Kelvin herself was destroyed fighting off the Nerada, a 24th century Romulan vessel that came from the future intent on destroying the Federation. The sacrifice of acting Captain George Kirk not only saved most of the crew, but did enough damage to the Nerada to forstall its attack and allow the Federation to develop far more powerful vessels.