| Shahab-4 (IRIS) | |
| Function: | Disputed |
| Manufacturer: | Iran |
The Shahab-4 (Persian: شهاب ۴, meaning "Meteor-4") (a.k.a. IRIS) was an unbuilt Iranian rocket, derived from the Shahab-3 medium-range ballistic missile. According to Iran it was intended to be a space launch vehicle,[1] after a slip by the Defense Minister in which he acknowledged it as a "more capable ballistic missile than the Shahab-3".[2] According to Western observers, it was intended to be part of a nuclear-capable ballistic missile.[3]
The IRIS/Shahab-4 project was initiated in 1988, but according to some sources, it never went beyond the drawing board. The design heritage of the IRIS was later incorporated into the Safir.[4]
In 1997, an American satellite captured evidence of a Shahab-4 test facility in Parchin.
In 1999, it was suspected that the Shahab-4 was largely derived from NPO Yuzhnoye's R-12 Dvina, which in its single-stage variant, had a maximum range of 2,000km and a circle of equal probability of 2,400m.[3] The dual-stage R-12 Dvina was capable of lifting payloads into orbit.