The AJ-60A rocket motor was developed between 1999 and 2003 for use on the Atlas V.[2]
On January 19, 2006 theNew Horizons spacecraft to Pluto was launched directly into a solar-escape trajectory at 16.26 kilometers per second (58,536 km/h; 36,373 mph) from Cape Canaveral using an Atlas V version with 5 of these SRBs and Star 48B third stage.[3]New Horizons passed the Moon's orbit in just nine hours.[4][5]
In 2015, ULA announced that the Atlas V will switch to newGEM 63 boosters produced byNorthrop Grumman Innovation Systems. (GEM 63XL, a stretched version of the GEM 63 booster is used on theVulcan rocket.)[6] The firstAtlas V launched with GEM 63 boosters on November 13, 2020.[7]
AJ-60A is a solid fueled rocket burningHTPB-basedcomposite solid propellant.[8] The casing is composed of agraphite-epoxy composite, and the engine throat and nozzle are made ofcarbon-phenolic composite. As configured for use on Atlas V, the nozzle is fixed at a 3 degree cant away from the attachment point, but Aerojet offers a variant with thrust vectoring capability.[2] The Atlas V configuration also features an inward slantingnosecone, but it is available with a conventional nosecone or none at all for use on other rockets. The stages are designed to be transported by truck.[8]