S-I — Mediated Wiki

{{short description|First stage of the Saturn I rocket}} {{Infobox rocket stage |name=S-I |status=Retired |country-origin=United States |last=July 30, 1965 |first=October 27, 1961 |family=Saturn |image=S-I rocket stage.jpg |success=10|launches=10 |rockets=Saturn I |diameter=6.5 m (21.4 feet) |length= |height=24.5 m (80.3 feet) |country=United States |caption=S-I diagram |manufacturer=Chrysler |propmass=397,414 kg (854,101 lb) |mass=432,681 kg (953,898 lb) |empty=45,267 kg (99,796 lb) |stagedata= {{Infobox rocket/stage |name=S-I engine details |fuel=RP-1 / LOX |time=150 s |thrust=(vac) 7,582.1 KN (1,704,524 lbf) |engines=8 H-1 engines |SI=289 sec }} }} The '''S-I''' was the first stage of the Saturn I rocket used by NASA for the Apollo program.<ref>{{Cite web|last=|first=|date=|title=S-I stage|url=http://www.astronautix.com/s/s-istage.html|url-status=live|archive-url=https://web.archive.org/web/20161228040121/http://astronautix.com/s/s-istage.html|archive-date=December 28, 2016|access-date=|website=}}</ref>

== Design ==

The S-I stage was powered by eight H-1 rocket engines<ref>{{Cite web|last=|first=|date=|title=Saturn family|url=https://space.skyrocket.de/doc_lau_fam/saturn.htm|access-date=|website=}}</ref> burning RP-1 fuel with liquid oxygen (LOX) as oxidizer. The design of the S-I was based on Jupiter and Redstone tanks to leverage existing chains. A central Jupiter tank<ref>{{Cite web|last=|first=|date=|title=Saturn Illustrated Chronology – Part 1|url=https://history.nasa.gov/MHR-5/part-1.htm|access-date=|website=}}</ref> was surrounded by a cluster of eight Redstone tanks. Four of these Redstone tanks contained LOX and four contained RP-1. The outer tanks were painted to alter thermal conditions inside the tanks and to provide a "roll pattern" used to estimate radial motion during flight.<ref>{{Cite web|last=|first=|date=|title=Saturn Illustrated Chronology - Part 2|url=https://history.nasa.gov/MHR-5/part-2.htm|access-date=|website=}}</ref> The engines were arranged in two clusters, a group of four fixed central engines and a group of four outer gimbaled engines. The gimbals allowed the stage to be controlled with thrust vectoring. On launches after SA-5, eight fins were added to enhance control during atmospheric flight.

== History == The S-I stage was developed by Chrysler and consisted of 9 tanks that were previously used on existing rockets. The central tank was a Jupiter tank that held liquid oxygen. This Jupiter tank was sounded by eight Redstone tanks, four for liquid oxygen and four for RP-1. The first four launches had no fins on the S-I, but the remaining six added them to improve stability during atmospheric flight.<ref>{{Cite web|last=|first=|date=|title=Saturn I & IB Rockets|url=https://historicspacecraft.com/Rockets_Saturn.html|access-date=|website=}}</ref> The initial launch of the Saturn I consisted of an active S-I, an inactive S-IV and inactive S-V stage. Tensions were high as a launch vehicle of this size had never flown before. The S-I was partially loaded with propellant to lessen the destruction if an anomaly occurred near or on the pad.<ref>{{Cite web|last=|first=|date=|title=Saturn I|url=http://www.astronautix.com/s/saturni.html|url-status=live|archive-url=https://web.archive.org/web/20160820171246/http://www.astronautix.com/s/saturni.html|archive-date=August 20, 2016|access-date=|website=}}</ref> In the end, the launch was successful and the subsequent SA-5 launch was identified by John F. Kennedy as the launch that put the U.S. above the USSR in terms of lift capability.<ref>{{Cite web|last=|first=|date=|title=President John F. Kennedy's Remarks at Brooks Air Force Base, San Antonio, TX – November 21, 1963|url=https://www.youtube.com/watch?v=6DTX9OiKi9U&t=6m4s|access-date=|website=}}</ref>

== Flight history == {| class="wikitable" |+ !Mission serial number !Launch date (UTC) !Launch notes |- |SA-1 |October 27, 1961 15:06:04 |First test flight. Block I. Suborbital. Range: 398 km. Apogee: 136.5 km. Apogee Mass: 115,700 lb (52,500 kg). Dummy S-IV and S-V stages. |- |SA-2 |April 25, 1962 14:00:34 |Second test flight. Block I. Suborbital. 86,000 kg water released at apogee of 145 km as part of Project Highwater. Dummy S-IV and S-V stages. |- |SA-3 |November 16, 1962 17:45:02 |Third test flight. Block I. Suborbital. 86,000 kg water released at apogee of 167 km. Dummy S-IV and S-V stages. Second and last Project Highwater flight. |- |SA-4 |March 28, 1963 20:11:55 |Fourth test flight. Block I. Suborbital. Dummy S-IV second stage and S-V third stage. Apogee: 129 km. Range: 400 km. |- |SA-5 |January 29, 1964 16:25:01 |First live S-IV second stage. First Block II. First to orbit: 760 x 264 km. Mass: 38,700 lb (17,550 kg). Decayed 30 April 1966. |- |SA-6 |May 28, 1964 17:07:00 |First Apollo boilerplate CSM launch. Block II. Orbit: 204 x 179 km. Mass: 38,900 lb (17,650 kg). Apollo BP-13 decayed 1 June 1964. |- |SA-7 |September 18, 1964 16:22:43 |Second Apollo boilerplate CSM launch. Block II. Orbit: 203 x 178 km. Mass: 36,800 lb (16,700 kg). Apollo BP-15 decayed 22 September 1964. |- |SA-9 |February 16, 1965 14:37:03 |Third Apollo boilerplate CSM. First Pegasus micrometeoroid satellite. Orbit: 523 x 430 km. Mass: 3,200 lb (1,450 kg). Pegasus 1 decayed 17 September 1978. Apollo BP-26 decayed 10 July 1985. |- |SA-8 |May 25, 1965 07:35:01 |Fourth Apollo boilerplate CSM. Only night launch. Second Pegasus micrometeoroid satellite. Orbit: 594 x 467 km. Mass: 3,200 lb (1,450 kg). Pegasus 2 decayed 3 November 1979. Apollo BP-16 decayed 8 July 1989. |- |SA-10 |July 30, 1965 13:00:00 |Third Pegasus micrometeoroid satellite. Orbit: 567 x 535 km. Mass: 3,200 lb (1,450 kg). Pegasus 3 decayed 4 August 1969. Apollo BP-9A decayed 22 November 1975. |}

== References ==  {{reflist}}

Category:Rocket stages Category:NASA space launch vehicles Category:Saturn I Category:Saturn C-2 Category:Saturn A-1