France selects Safran HRG navigation technology for nuclear deterrence programmes

The French Navy conducts its first acceptance firing of an M51.3 missile from the SSBN Le Vigilant on 6 October 2026. (French Ministry of the Armed Forces)

Safran Electronics & Defense has been selected for three inertial navigation programmes supporting France's nuclear deterrence, extending the use of its hemispherical resonator gyroscope (HRG) technology to future submarines, ballistic missiles, and Rafale combat aircraft, the company announced on 2 November 2026.

An HRG measures rotation through changes in the vibration pattern of a tiny hemispherical silica shell, providing orientation data that helps an inertial navigation system operate without satellite signals.Safran's HRG Dual Core architecture uses six HRG Crystal sensors rather than three and incorporates self-calibration to reduce measurement errors, according to an abstract by Safran Federal Systems representatives for the Institute of Navigation's Joint Navigation Conference, held in June 2026.

The company produces 10,000 HRGs annually and plans to increase output to 30,000 units by 2032. Safran announced a EUR120 million (USD138.5 million) investment in its Montluçon facility in June to support this expansion. These production figures cover its wider HRG business.

For the future M51.4 submarine-launched ballistic missile (SLBM), Safran's new CI4 inertial navigation unit will use HRG Dual Core technology to improve accuracy in a more compact package, according to the November release. The company already supplies inertial navigation units for current M51 variants.

France's Directorate General of Armament (DGA), awarded ArianeGroup the M51.4 development and production contract on 28 August 2025. Announcing the award on 12 September 2025, DGA said the missile would enter service during the following decade aboard both existing Le Triomphant-class ballistic missile submarines (SSBNs) and future third-generation SSBNs.