The Long Range Stand-Off program is an Air Force initiative to replace the nuclear-capable AGM-86 Air Launched Cruise Missile deployed on the B-52H Stratofortress strategic bomber.
The ALCM is the current nuclear-capable cruise missile in the U.S. inventory after the retirement of the TLAM-N Tomahawk. It’s AGM-86B model can mount a W80 thermonuclear warhead with a yield of up to 200 kilotons.
The LRSO would be mounted on the B-52H, B-2 Spirit stealth bomber and the future B-21 Raider bomber currently under development. The Long Range Stand-Off, or LRSO, weapon will be developed to replace the aging AGM-86B Air Launched Cruise Missile or ALCM, currently able to fire from a B-52. The AGM-86B has far exceeded its intended life span, having emerged in the early 1980s with a 10-year design life, Air Force statements said. Unlike the ALCM which fires from the B-52, the LRSO will be configured to fire from B-2 and B-21 bombers as well, service officials said. While Air Force officials say that the current ALCM remains safe, secure and effective, it is facing sustainment and operational challenges against evolving threats, service officials also acknowledge.
The rapid evolution of better networked, longer-range, digital air-defenses using much faster computer processing power will continue to make even stealth attack platforms more vulnerable; current and emerging air defenses, such as Russian-built S-300s and S-400s are able to be cued by lower-frequency “surveillance radar” — which can simply detect that an enemy aircraft is in the vicinity — and higher-frequency “engagement radar” capability. This technology enables air defenses to detect targets at much farther ranges on a much larger number of frequencies including UHF, L-band and X-band.
The Air Force plans to start fielding LRSO by 2030.