Juno I

Quick Facts About the Juno I rocket:

- Type: Orbital launch vechile.

- Origin : United States.

- In service : 31 January 1958 – 23 October 1959.

- Mass : 29 060 kg.

- Length : 21.2 m (70 ft).

- Diameter : 1.78 m (5 ft 10 in).

- Payload to LEO: 11 kg (24 lb)

- Propellant : First stage: Hydyne/LOX, Second stage: Polysulfide-aluminum and ammonium perchlorate (Solid), Third stage: Polysulfide-aluminum and ammonium perchlorate (Solid), Fourth stage: Polysulfide-aluminum and ammonium perchlorate (Solid).

- Engines: First stage: 1 Rocketdyne A-7 with thrust of 416.18 kN (93,560 lbf), Second stage: 11 Solid rockets with thrust of 73.4 kN (16,500 lbf), Third stage: 3 Solid rockets with thrust of 20.0 kN (4,500 lbf), Fourth stage: 1 Solid rcoket with thrust of 6.7 kN (1,500 lbf).

Juno 1 is a member of the Redstone rocket family, it was derived from the Jupiter-C sounding rocket. It is commonly confused with the Juno II launch vehicle, which was derived from the PGM-19 Jupiter medium-range ballistic missile.

Juno-I launched the Explorer 1 satellite on 31 January, 1958, becoming the first U.S. satellite, as well as discovering the Van Allen radiation belt.

The Juno I consisted of a Jupiter-C first stage, based on the Redstone missile; with three additional solid fuel stages based on the Sergeant missile to provide the added impulse to achieve orbit. The fourth stage was mounted on top of the "tub" of the third stage, and fired after third-stage burnout to boost the payload and fourth stage to an orbital velocity of 8 kilometres per second (29,000 km/h; 18,000 mph), with an acceleration of 25–51 g. The tub along with the fourth stage were set spinning while the rocket was on the launch pad to provide gyroscopic force in lieu of a guidance system that would have required vanes, gimbals, or vernier motors. This multi-stage system, designed by Wernher von Braun in 1956 for his proposed Project Orbiter, obviated the need for a guidance system in the upper stages. It was the simplest method for putting a payload into orbit but having no upper-stage guidance, the payload could not achieve a precise orbit. Both the four-stage Juno I and three-stage Jupiter-C launch vehicles were the same height (21.2 meters), with the added fourth-stage booster of the Juno I being enclosed inside the nose cone of the third stage.