What year was the first component of the space station which Cygnus CRS OA-6 completed 5 flights to launched into orbit?
Cygnus CRS OA-6: Cygnus CRS OA-6, also known as Orbital Sciences CRS Flight 6, is the sixth flight of the Orbital ATK unmanned resupply spacecraft Cygnus and its fifth flight to the International Space Station under the Commercial Resupply Services contract with NASA. International Space Station:  Its first component launched into orbit in 1998, and the ISS is now the largest human-made body in low Earth orbit and can often be seen with the naked eye from Earth.
1998