the Swedish Navy and became operational in 1985. The Swedish Air Force received their missiles a couple of years later. The original RBS 15 Mk. I was produced from 1985 to 1990. Work on a further developed version, the RBS 15 Mk. II, began in the early 1980s, but it took until 1994 to get a development contract for the upgraded anti-ship missile. The Mk. II has the same range (70+ km), but the mid-course and terminal guidance system, as well as the radar and IR signature were upgraded. The Mk. II has been produced since 1998. Development of the RBS 15 Mk. III began in the mid-1990s. It is produced by Saab in co-operation with Diehl Defence of Germany. Emphasis was put on increased range (due to larger fuel capacity and new fuel the range has been increased to some 200 km), improved accuracy (integrated GPS) and selectable priority targeting, which improved the weapon system's flexibility. The Mk. III was selected for the German Navy's s. Finnish truck maker Sisu produces missile launch trucks for RBS 15. The Mk. III has been in production since 2004. In March 2017 Saab received an order for a new generation anti-ship missile to replace the RBS 15, valued at 3.2 billion SEK. The following year, SAAB unveiled the RBS 15 Mk. IV Gungnir, again produced with Diehl. Unlike Mk. III, the Mk. IV Gungnir can be fired from a truck, making it capable of launching from air, sea, or land. Gungnir missiles have been ordered for the Swedish Navy, with the first weapons scheduled for delivery in the mid-2020s. Development phase The missile was developed from the RB 04 missile that was used by the Swedish air force. The front of the missile was retained, including the warhead, but the rear received new wings and a turbofan engine replaced the rocket previously used. The RBS 15 underwent trials on the missile FAC from 1983 and became operational with the Swedish Navy in 1985. The s were to have four vertical missile launch tubes for RBS 15 missiles in an extended hull, canceled due to budget constraints and to not fitting the way Swedish submarines operated. Versions RBS 15 Mk. I Powered by a French Microturbo TRI-60 engine, with a thrust of 3.73 kN (380 khp/830 lbf). Range 70+ km RBS 15F An Mk. I adapted for air launch. Entered service in 1989.