Lockheed Martin’s [LMT] Joint Air-to-Surface Standoff Missile Extended Range (JASSM-ER) variant successfully completed the Air Force’s initial operation test and evaluation (IOT&E) flight testing, according to a company statement.

JASSM-ER scored 20 successes in 21 fights, a success rate of 95 percent, according to Lockheed Martin. The missiles were employed in all of the operational flight modes at the full range of release conditions.

Lockheed Martin Missiles and Fire Control Long Range Strike Systems Program Manager Dave Melvin said in a statement the successful completion of the testing program was the final milestone before a planned full-rate production (FRP) decision expected later this year.

Lockheed Martin spokeswoman Melissa Hilliard said JASSM-ER received its Milestone C low-rate initial production (LRIP) decision in January 2011 and that the first lot of JASSM-ER missiles is currently in production for delivery between July and September.

JASSM is an autonomous, air-to-ground, precision-guided standoff missile armed with a penetrator and blast fragmentation warhead. It also employs an infrared seeker and enhanced digital anti-jam Global Positioning System (GPS) to find specific points on targets.

Lockheed Martin is also working on an improved fuse for its regular JASSM variant. The FMU-162/B Electronic Safe and Arm Fuse (ESAF) would replace the electro-mechanical fuses currently used on JASSM. Hilliard said ESAF testing is ongoing and qualification testing is expected to conclude by the first quarter of 2016 with an ESAF critical design review slated for third quarter 2015. Lockheed Martin previously said it anticipated having the ESAF fully qualified and ready for production by 2015.

JASSM, a $6 billion cruise missile program, came close to being canceled in 2009 after years of test failures in which the weapon failed to detonate on impact.