USA-128, also known as GPS IIA-18, GPS II-27 and GPS SVN-30, is an American navigation satellite which forms part of the Global Positioning System. It was the eighteenth of nineteen Block IIA GPS satellites to be launched. USA-128 was launched at 08:49:00 UTC on 12 September 1996, atop a Delta II carrier rocket, flight number D238, flying in the 7925-9.5 configuration. The launch took place from Launch Complex 17A at the Cape Canaveral Air Force Station, and placed USA-128 into a transfer orbit. The satellite raised itself into medium Earth orbit using a Star-37XFP apogee motor.