|Manufacturer||United Launch Alliance|
(formerly Boeing and McDonnell Douglas)
|Country of origin||United States|
|Used on||Delta 4000|
|Height||5.9 meters (19 ft)|
|Diameter||2.4 meters (7.9 ft)|
|Gross mass||6,954 kilograms (15,331 lb)|
|Propellant mass||6,004 kilograms (13,237 lb)|
|Thrust||43.63 kilonewtons (9,810 lbf)|
|Specific impulse||319 seconds (3.13 km/s)|
|Burn time||431 seconds|
|Propellant||Aerozine 50 / N|
It continued to serve as the second stage for subsequent variants of the Delta rocket.
The Delta-K had a long heritage to the first Able stage used in Project Vanguard. The AJ-10 engine was first used in the Able second stage of the Vanguard rocket, as the AJ10-118 configuration. It was initially fueled by nitric acid and UDMH. An AJ10 engine was first fired in flight during the third Vanguard launch, on 17 March 1958, which successfully placed the Vanguard 1 satellite into orbit.