On 5 December 2018, representatives of the Federal Agency for Equipment, Information Technology and Use of the Federal Armed Forces (BAAINBw) and Krauss-Maffei Wegmann GmbH & Co. KG (KMW) signed the contract to convert 18 more rocket launchers M270 MARS in MARS II. A first batch had already been converted in 2013. The budget allocated for this second wave of conversions is about 18 million €.

Firing of rockets by a MARS II (Picture source: Bundeswehr)

With the approval of the Defense and Budget Committees and the signing of the contract, both parties begin to implement them. The conversion of 18 additional rocket launchers will be completed by 2022. The development and acquisition of GMLRS missiles (multi-guided rocket launcher system) required an upgrade of MARS launchers to evolve into MARS II. This interaction between MARS II and GMLRS allows extremely precise control, about 7 meters.

In cooperation with various European manufacturers, KMW is currently improving and modernizing the combat value for several countries: from MARS to MARS II for the German Army, an improvement of the MLRS for the Italian Army, and Lance-Roquettes Unitaire (LRU) for France. The renewal of the MARS equipment includes a laser gyroscope and a technical development of the GPS navigation system, designated ERGR, which succeeds the initial GPS Precision Lightweight (PLGR) receiver (integration of the European driving system Missile Guidance System (EFCS) (GMLRS), then the hydraulic missile container elevation mechanism was converted into KMW-developed Electric Launch Drive System (ELDS) to increase pointing speed and speed up loading by up to 60% off the MARS I system, and the modernization "kit" includes the installation of a new, fully automatic, ozone-free extinguishing system for the engine compartment, only mounted in Germany and Italy.

For the record, the M993 MARS multiple rocket launcher was developed from 1983 jointly by the United States, Germany, Great Britain, France and Italy as part of the international MLRS program (Multiple-Launch Rocket System). The MARS system was introduced to the Bundeswehr in 1990 under the designation MARS - Mittleres Artillerieraketensystem.

The MARS II can fire missiles of M31 Unitary type derived from the M30 currently in equipment, armed with a single explosive charge head for use in urban and mountainous areas; this craft is flying at Mach 3,4. The range of the rocket extends from 60 km for the M30 to 80 km for the M31 which contains a load of 404 submunitions M85. Several tests have verified that the range of 100 km has been largely exceeded with modified warheads, where it is possible to define the nominal or vertical approach angles of the rocket. The increase of the range up to 140 km is planned.

The rocket launcher has two launch containers, each containing six missiles that can be fired in less than a minute. It takes a maximum of seven minutes between power on and "combat ready" status; then, it takes a maximum of 30 seconds for a missile / rocket container firing cycle.

In addition to the M30 and M31 missile models used in the Bundeswehr, the MARS II can fire various types of "classic" rockets and missiles developed by or with the United States, plus three specifically German models:
- M32 SMArt: modernization of the M30 by Diehl Defence, containing 4 SMArt anti-tank submunitions and a new flight software;
- AT2 MLRS: SCATMIN rocket derived from the American M26 containing 28 AT2 antitank mines; the range is 38 km;
- 110 mm rocket with explosive warhead from the LARS2 system reused for training purposes. This conversion requires a kit that includes a specific pod of 6 rockets.
Currently, both GMLRS variants - Unitary and SMArt - are supported by the MARS II Fire Control System. Other types of ammunition are under development. The rate of fire is high: twelve rockets / missiles in about a minute. To increase its terminal efficiency, the MARS II offers a high accuracy (less than 7 meters) to limit the number of rockets needed to treat a target but also a graduation effects by several modes of triggering its military load.

The most powerful version of the US arsenal is the BAT (Brilliant Anti-Armor Technology) submunition. An MLRS missile can carry two BATs. It uses acoustic and infrared sensors to locate its target and is autonomous in that it is able to search for and hit it independently. Their dual steering system also makes it possible to hit moving targets under difficult conditions. Once the target is detected, the rotating aerodynamic control surfaces are activated and "pilot" the missile towards the target until the detonation. This ammunition can be fired by the German MARS in the case of the NATO alliance. The US Army Tactical Missile (ATACMS) is another missile designed to be fired by the M142 High Mobility Artillery Rocket System (HIMARS) multiple rocket launcher; it can cover distances up to 300 km without following a ballistic trajectory.

In the Bundeswehr, on 6 April 2011, the first MARS II was handed over to the artillery school in Idar-Oberstein. In 2012, the Roquette Artillery Battalion 132 (RakArtBtl 132) was equipped in Sondershausen as the first unit on MARS II; the unit was disbanded in March 2013. In 2015, the 3rd Battery of Artillery Battalion 131 (formerly Artillery Observation Battalion 131) in Weiden, Upper Palatinate, received the MARS II. In December 2017, Artillery Battalion 345 and the Army Development Bureau (Amt für Heeresentwicklung) tested the firing of twelve M31 missiles (GMLRS-U) with an 81.6 kg fragmentation warhead.

In France, the LRU (Lance-Roquettes Unitaire, equivalent of MARS II) equips the 1st Artillery Regiment established in Belfort. It is part of the digital fire command and control system for ATLAS artillery.