A test on Sept. 21, 2000, may have been a test of the Shahab-3D, a liquid-/solid-propellant missile that Iran has reportedly been developing as a space launch vehicle, also called the IRIS booster. The IRIS launch vehicle consists of what appears to be a Shahab-3 first stage with a bulbous front se ction designed to contain a second-stage solid rocket motor and a payload. Such a design is unlikely to be used to launch a significant payload unless mated to additional stages below. The failure of the test may have represented a significant setback to the Iranian space program. Shahab-3D could a lso be a ballistic missile variant of the IRIS . The Shahab-3D strongly resembles the North Korean Taepo-dong 2 second and third stages, indicating possible Iranian and North Korean cooperation on a joint space program.