Armement Air-Sol Modulaire. The AASM (), also known as AASM Hammer ("Hammer" standing for "Highly Agile Modular Munition Extended Range"), is a French, all-weather, smart air-to-surface stand-off weapon developed by Safran Electronics & Defense. Meant for both close air support and deep strike missions, the AASM is highly modular.

The AASM consists of a nose-mounted guidance section and a tail-mounted range extension kit (featuring winglets for maneuverability and a rocket booster) attached to either a , ,  or  class bomb (such as the Mark 80 series general purpose bombs). There are three variants of the AASM Hammer kit, with different guidance options depending on the target and operational context. The baseline variant features a hybrid inertial navigation system (INS) and a Global Positioning System (GPS) guidance system. The two other variants respectively integrate, in addition to the hybrid INS/GPS guidance system, either an infrared homing module or a laser guidance one in the nose-mounted guidance section for increased accuracy, and the ability to hit moving targets.

The AASM entered service in 2007 with the French Air Force and Naval Aviation, equipping the Dassault Rafale and Mirage 2000D.

Development 
The program started in 1997, when the Délégation Générale pour l'Armement (DGA), the French defense procurement agency, launched an international competition on the design for the weapon. In 2000, a contract was awarded to SAGEM (that became part of Safran before the end of the development) for an initial lot of AASM GPS/INS bomb kits, expected at the time to be delivered in 2004 and to enter service the following year.

Validation 
A test campaign to validate in flight the main performances of this AASM variant started on 6 December 2004, and ended on 26 July 2005.

While demonstrating excellent results, this campaign showed the need to change some of the aerodynamic features of the weapon. To compensate for delays in AASM deliveries in 2008 France ordered dual-mode (laser- and GPS/INS-guided) GBU-49 Enhanced Paveway II kits for integration with Mirage 2000D and Rafale fighter-bombers. The GPS/INS + IIR guided version completed its qualification tests on 9 July 2008, after three firings at the DGA's missile test range in Biscarosse. This 250 kg IR version performed a night launch from a Rafale fighter-bomber at DGA's Biscarosse test range in December 2010.

According to Safran Electronics & Defense, the weapon was launched at a range of more than 50 km from the target, which was hit within one meter. A 125 kg version was successfully test fired on 27 January 2009, and a laser guided variant was air-launched for the first time on 17 June 2010.

The 1000 kg version commenced testing in 2020, with inert separation trials from a Rafale. Qualification firings finished in early 2023 and a delivery of the first kits started the same year.

Cost 
According to French Senate's Comité des Prix de Revient des fabrications d'Armement (CPRA) cited by the daily La Tribune, the total cost of the AASM program including development costs and the delivery of 2348 kits is €846m. On that basis the per-weapon cost is $300,000 or twelve times the cost of the comparable American JDAM, although the latter has been manufactured in much larger quantities (~250,000 kits) and would be reasonable to expect a slight reduction of the cost ratio if larger contracts are signed and economies of scale are achieved.

The 2012 defence budget presented to the Senate reported the project had cost €592.2m (~US$800m) with a unit cost of €164,000, or €252,000 including development costs.

In 2017 La Tribune reported a unit cost of €120,000 for a new version called AASM Evolution (Block IV) with the aim by Safran to lower it to €80,000.

Variants 
AASM comes in several variants according to its size and the type of guidance used.

 The current model features a 250 kg bomb matched to a nose-mounted guidance kit and a rear-mounted range extension kit, containing a rocket booster and enlarged fins. A 125 kg model was first tested in 2009. The 1000 kg version finished testing in early 2023.
 As for guidance, the basic version combines data from a Global Positioning System (GPS) receiver and an inertial navigation system (INS) unit through Kalman filtering, achieving a  circular error probability (CEP). This "decametric" all-weather variant is complemented by a "metric" day/night fair weather version which adds infrared homing (IIR) guidance that matches the target area with a target model stored in its memory for a  CEP.
 A third version uses laser guidance instead of IIR allowing it to hit moving targets with more precision. It was qualified in April 2013.

In October 2010, these versions were given alphanumeric designations with the INS/GPS version becoming the SBU-38 (SBU=Smart Bomb Unit), the INS/GPS/IIR version becoming the SBU-64 and the INS/GPS/SALH version becoming the SBU-54; the system as a whole was renamed Hammer to make it more appealing to export customers.

Operational use 
The first order for AASM was placed by the DGA in 2000 for a total of 744 units; deliveries started in 2007 after a two-year delay in development. In 2009 a second order for 680 units was placed, by the end of that year deliveries had reached 334.

Afghanistan 
AASM made its combat debut on 20 April 2008, during the War in Afghanistan when a Rafale fighter dropped two in support of ground troops.

Libya 
On 24 March 2011, it was reported that an AASM bomb dropped from a Dassault Rafale was used to destroy a Libyan Air Force  G-2 Galeb light ground attack/trainer jet, the first Libyan warplane to challenge the no-fly zone during the 2011 Libyan civil war, on the runway just after the plane had landed at Misrata Airport. On 6 April 2011, it was reported that a AASM bomb dropped from a Dassault Rafale was used to destroy a Libyan tank at a range of 55 km. In Libya, 225 AASM bombs have been dropped 

"Also referred to as the Hammer, the AASM weapon has impressed during the campaign to date. Incorporating a precision guidance kit and propulsion system, the design will eventually be available for use with standard bombs weighing between 125 kg and 1 000 kg, although a 250 kg version is the only one currently in service. Sagem cites a range capability of more than 32nm from high altitude, or 8nm from low level. Launches can also be made from an off-axis angle of up to 90°, while up to six weapons can be fired against individual targets in a single pass and with just one trigger press." And "Libya represents the first opportunity for the French Air and Space to employ the Thales Damocles targeting pod, although the Navy gave the system its combat debut over Afghanistan in late 2010."

India

According to a report by Hindustan Times, India placed an order for "large numbers" of the Hammer in September 2020 and deliveries will be completed by the end of November 2020. The reports adds that the French Air and Space Force will transfer some of its supplies of Hammer to India to ensure immediate deliveries. India has started the process of integrating Hammer missile to its indigenous fighter Tejas.

Ukraine

On 16 January 2024, French president Emmanuel Macron announced France would be providing several hundred AASM Hammer precision-guided weapons to Ukraine, at a rate of 50 units per month in 2024. The first reported use of the AASM by Ukraine took place on 5 March 2024. They have been deployed from MiG-29s and Su-25s.

Operators

Current operators

See also

References

External links
 MBDA page
 Sagem page

Post–Cold War weapons of France
Military equipment introduced in the 2000s
Guided bombs
Aerial bombs of France
Air-to-surface missiles of France