US Explorer 1 (Juno I)
Historical
Four-stage, Redstone-derived Juno I vehicle that launched America's first satellite, Explorer 1, in response to Sputnik. This describes the launch vehicle, not the satellite payload. Data sourced from Astronautix and Wikipedia — reasonable consensus figures, good as a hand-key simulator starting point.
Geometry
Overall height21.2 m
Stage 1 diameter1.78 m
Fin span3.86 m (4 fins on stage 1)
Mass Properties
Gross liftoff massapprox. 29,060 kg
Propulsion
| Stage | Engine | Propellant | Thrust | Burn Time |
|---|---|---|---|---|
| Stage 1 | 1× Rocketdyne A-7 | Hydyne/LOX | approx. 416 kN | approx. 155 s |
| Stage 2 | 11× clustered solid “Baby Sergeant” | Solid | approx. 73 kN combined | approx. 6 s |
| Stage 3 | 3× clustered solid “Baby Sergeant” | Solid | approx. 20 kN combined | approx. 6 s |
| Stage 4 | 1× solid “Baby Sergeant” + payload | Solid | approx. 7 kN | approx. 6 s |
Aerodynamics
CDNot published; Redstone-derived stage-1 body with 4 fins, spin-stabilized solid upper-stage “tub” cluster
Flight Conditions
Launch siteCape Canaveral LC-26A, Florida
Achieved orbit (Explorer 1)approx. 358 × 2,550 km, inclination 33.2°