The S-V (pronounced "S-five") was the third stage of the

Saturn I The Saturn I was a rocket designed as the United States' first medium lift launch vehicle for up to low Earth orbit Payload (air and space craft), payloads.Terminology has changed since the 1960s; back then, 20,000 pounds was considered "heavy l ...

rocket. It was built by

Convair Convair, previously Consolidated Vultee Aircraft Corporation, was an American aircraft-manufacturing company that later expanded into rockets and spacecraft. The company was formed in 1943 by the merger of Consolidated Aircraft and Vultee ...

. It was designed to use two RL-10A-1 engines fueled by

liquid hydrogen Liquid hydrogen () is the liquid state of the element hydrogen. Hydrogen is found naturally in the molecule, molecular H2 form. To exist as a liquid, H2 must be cooled below its critical point (thermodynamics), critical point of 33 Kelvins, ...

(LH₂₎ and

liquid oxygen Liquid oxygen, sometimes abbreviated as LOX or LOXygen, is a clear cyan liquid form of dioxygen . It was used as the oxidizer in the first liquid-fueled rocket invented in 1926 by Robert H. Goddard, an application which is ongoing. Physical ...

(LOX) in tanks utilizing a common bulkhead to separate the propellants.

History

Convair Astronautics was awarded a contract to deliver the S-V stage for the

. The stage was intended to boost lift capacity for U.S. military launches in the 1960s. The S-V would ultimately fly as the third stage on early launches of the Saturn I.

delivered two S-V stages in February 1961 with one being flown on SA-1 attached to an also inert S-IV, the second was used for dynamic testing of the complete Saturn I before being later flown. In May 1961 NASA eliminated the requirement for all Saturn I launches to be flown with S-V's by flying in a two-stage only version. Despite this, the stage would fly four times in total. With the introduction of the Saturn IB and the needs of the military fulfilled on other launches, all further launches would be on either the

Saturn IB The Saturn IB (also known as the uprated Saturn I) was an American launch vehicle commissioned by the National Aeronautics and Space Administration (NASA) for the Apollo program. It uprated the Saturn I by replacing the S-IV second stage (, 43,3 ...

Saturn V The Saturn V is a retired American super heavy-lift launch vehicle developed by NASA under the Apollo program for human exploration of the Moon. The rocket was human-rated, had multistage rocket, three stages, and was powered by liquid-propel ...

, neither of which used the S-V. A version of this stage was also used on the Atlas-LV3C as the

Centaur A centaur ( ; ; ), occasionally hippocentaur, also called Ixionidae (), is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse that was said to live in the mountains of Thessaly. In one version o ...

, modern derivatives of which are still flown today, making it the only Saturn rocket stage still currently operating.

Flight history

Ultimately, the S-V would go on to fly four times between 1961 and 1964. Each of which were flown on suborbital test flights of the Saturn I. Because of the suborbital nature of these flights, each S-V was filled with water to act as ballast, making the stage inert. The water was released in space twice for

Project Highwater Project Highwater was an experiment carried out as part of two of the test flights of NASA's Saturn I launch vehicle (using battleship upper stages), successfully launched into a sub-orbital trajectory from Cape Canaveral, Florida. The Highwat ...

. Modern derivatives of the stage are still in use today on the

Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas (rocket family), Atlas launch vehicle family. It was developed by Lockheed Martin and has been operated by United Launch Alliance (ULA) since 2006. Primarily used to ...

and the

Vulcan Centaur Vulcan Centaur is a heavy-lift launch vehicle developed and operated by United Launch Alliance (ULA). It is a two-stage-to-orbit launch vehicle consisting of the Vulcan first stage and the Centaur second stage. Replacing ULA's Atlas V and Del ...

. {, class="wikitable" , + !Flight Number !Launch date (UTC) !Notes , - , SA-1 , October 27, 1961 15:06:04 , First test suborbital flight. Apogee: 136.5 km. Inactive S-IV and S-V stages. , - ,

SA-2 The S-75 (Russian: С-75; NATO reporting name SA-2 Guideline) is a Soviet-designed, high-altitude air defence system. It is built around a surface-to-air missile with command guidance. Following its first deployment in 1957 it became one of the ...

, April 25, 1962 14:00:34 , Second suborbital test flight. 86,000 kg water released at apogee of 145 km. Inactive S-IV and S-V stages. , - , SA-3 , November 16, 1962 17:45:02 , Third suborbital test flight. 86,000 kg water released at apogee of 167 km. Inactive S-IV and S-V stages. , - ,

SA-4 The 2K11 ''Krug'' (; English: 'circle') is a Soviet Union, Soviet and now Russian medium-range, medium-to-high altitude surface-to-air missile (SAM) system. The system was designed by NPO Novator and produced by Kalinin Machine Building Plant. I ...

, March 28, 1963 20:11:55 , Fourth suborbital test flight. Apogee: 129 km. Inactive S-IV and S-V stages.

References

__FORCETOC__ Rocket stages NASA space launch vehicles