Editing Juno I (section)

== Launch vehicle ==
[[File:Juno I.svg|left|thumb|200x200px|Juno I diagram]]
The Juno I consisted of a [[Jupiter-C]] first stage, based on the [[PGM-11 Redstone|Redstone missile]]; with three additional [[solid fuelled rocket|solid fuel]] stages based on the [[MGM-29 Sergeant|Sergeant missile]] to provide the added impulse to achieve orbit.<ref name=":0">{{Cite web |title=Juno-1 |url=https://space.skyrocket.de/doc_lau_det/juno-1.htm |access-date=2023-10-15 |website=Gunter's Space Page |language=en}}</ref> 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 {{cvt|8|km/s}}, with an acceleration of 25–51 g. The tub along with the fourth stage were set spinning while the launch vehicle was on the launch pad to provide gyroscopic force in lieu of a guidance system that would have required [[thrust vectoring]], [[vernier thrusters]], or a [[reaction control system]]. The booster guidance package (with the tub attached) separated from the first stage after burnout to provide attitude control until second stage ignition.<ref name="bello1959" /> 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 ({{cvt|21.2|m}}), with the added fourth-stage booster of the Juno I being enclosed inside the nose cone of the third stage.