The Juno II was a modified Jupiter rocket with upper stages and payload sections. Its single engine-just like the Jupiter's-could be gimbaled during launch for steering control. Juno II played an important role in the history of space flight. In March, 1959 the vehicle launched Pioneer IV on America's first successful lunar flyby mission. Pioneer IV was also the first U. S. probe to go into orbit around the sun.
This vehicle launched a number of satellites into Earth orbit, including Explorer VII (October, 1959), which measured X-rays from the sun, and Explorer XI (April, 1961), the first gamma ray satellite.
Length: 77.1ft (23.5m)
Diameter: 8.8ft (2.7m)
Weight: 110,495lbs (492,700N)
Thrust: 150,000lbs (667,233N)
(stage 1) Liquids oxygen and kerosene
(upper stages) Rubber-based solid propellant
· Chrysler Corporation (fuselage)
· Rocketdyne Division, North American Aviation, Inc. (first stages propulsion)
· Thiokol for the Jet Propulsion Laboratory (upper stage propulsion)