N-II (rocket)

The N-II, also written N-2, was a Japanese derivative of the American Delta rocket, produced under licence in Japan, which replaced the N-I in Japanese service. It used a Thor-ELT first stage, a Delta-F second stage and nine Castor solid rocket motors, with a Star-37E or Burner-2 upper stage on most flights, identical to the American Delta 0100 series configurations. Eight were launched between 1981 and 1987 and all eight launches were successful. It was replaced by the H-I, which kept the licence-built first stage but introduced Japanese-produced upper stages, so the N-II was the last of the Japanese rockets whose upper stages were American designs.