Castor is a family of

solid-fuel rocket A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses Rocket propellant#Solid chemical propellants, solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder. The incepti ...

stages and boosters built by

Thiokol Thiokol was an American corporation concerned initially with rubber and related chemicals, and later with rocket and missile propulsion systems. Its name is a portmanteau of the Greek words for sulfur () and glue (), an allusion to the company ...

(now

Northrop Grumman Northrop Grumman Corporation is an American multinational Aerospace manufacturer, aerospace and Arms industry, defense company. With 97,000 employees and an annual revenue in excess of $40 billion, it is one of the world's largest Arms industry ...

) and used on a variety of

launch vehicle A launch vehicle is typically a rocket-powered vehicle designed to carry a payload (a crewed spacecraft or satellites) from Earth's surface or lower atmosphere to outer space. The most common form is the ballistic missile-shaped multistage ...

s. They were initially developed as the second-stage motor of the Scout rocket. The design was based on the MGM-29 Sergeant, a

surface-to-surface missile A surface-to-surface missile (SSM) is a missile designed to be launched from the ground or the sea and strike targets on land or at sea. They may be fired from hand-held or vehicle mounted devices, from fixed installations, or from a ship. They ar ...

developed for the

United States Army The United States Army (USA) is the primary Land warfare, land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of th ...

at the

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center (FFRDC) in La Cañada Flintridge, California, Crescenta Valley, United States. Founded in 1936 by Cali ...

Versions

Flown versions

Castor 1

:The Castor 1 was first used for a successful suborbital launch of a

Scout X-1 Scout X-1 was an American expendable launch system and sounding rocket which was flown seven times between August 1960 and October 1961. Four orbital and three suborbital launches were made, with four of the launches resulting in failures. The ...

rocket on September 2, 1960. :It was long, in diameter, and had a burn time of 27 seconds. Castor 1 stages were also used as strap-on boosters for launch vehicles using

Thor Thor (from ) is a prominent list of thunder gods, god in Germanic paganism. In Norse mythology, he is a hammer-wielding æsir, god associated with lightning, thunder, storms, sacred trees and groves in Germanic paganism and mythology, sacred g ...

first stages, including the

Delta D The Delta D, Thrust Augmented Delta or Thor-Delta D was an American expendable launch system used to launch two communications satellites in 1964 and 1965. It was derived from the Delta C, and was a member of the Delta (rocket family), Delta fami ...

. (A Delta-D was used in 1964 to launch Syncom-3, the first satellite placed in a

geostationary orbit A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular orbit, circular geosynchronous or ...

.) Castor 1 stages were used in 141 launch attempts of Scout and Delta rockets, only 2 of which were failures. They were also used on some thrust-assisted

Thor-Agena Thor-Agena was a series of orbital launch vehicles. The launch vehicles used the Douglas Aircraft Company, Douglas-built Thor (rocket family), Thor first Multistage rocket, stage and the Lockheed Corporation, Lockheed-built RM-81 Agena, Agena ...

launchers. The last launch using a Castor 1 was in 1971.

Castor 2

:The Castor 2 was an upgraded version of the Castor 1. It was first used on a Scout in 1965, and continued to be used on Scouts until the last Scout launch, in 1994. Castor 2 stages were also used as the strap-on boosters for the

Delta E The Delta E, or Thor-Delta E was an American expendable launch system used for twenty-three orbital launches between 1965 and 1971. It was a member of the Delta family of rockets. The first stage was a Thor missile in the DSV-2C configuration, ...

, and for the Japanese-built N-I, N-II and H-I rockets. It retained the same diameter as the Castor 1, and was from 5.96 m to 6.27 m in length.

Castor 4

:The Castor 4, along with its A and B variants, were expanded to 1.02 m in diameter. They were used as strap-ons on some Delta,

Delta II Delta II was an expendable launch system, originally designed and built by McDonnell Douglas, and sometimes known as the Thorad Delta 1. Delta II was part of the Delta rocket family, derived directly from the Delta 3000, and entered service in ...

, Atlas IIAS, and Athena RTV launch vehicles. They were also planned to serve as the first stage of the Spanish Capricornio booster, however, no such flights occurred before the project was cancelled. :Castor 4B is used in the European Maxus Programme, with launches from

Esrange , , , , , , , , , Esrange Space Center is a rocket range and research centre located about 40 kilometers east of the town of Kiruna in northern Sweden. It is a base for scientific research with high-altitude balloons, investigation of the a ...

in Sweden. : Certain versions of the

H-IIA H-IIA (H-2A) is an active expendable launch system operated by Mitsubishi Heavy Industries (MHI) for the Japan Aerospace Exploration Agency. These liquid fuel rockets have been used to launch satellites into geostationary orbit; lunar orbi ...

rockets flown by

JAXA The is the Japanese national air and space agency. Through the merger of three previously independent organizations, JAXA was formed on 1 October 2003. JAXA is responsible for research, technology development and launch of satellites into o ...

used either two or four strap-on boosters developed and produced by

Alliant Techsystems Alliant Techsystems Inc. (ATK) was an American Aerospace manufacturer, aerospace and arms industry, arms manufacturer headquartered in Arlington County, Virginia. The company operated across 22 states, Puerto Rico, and internationally. ATK reven ...

. These boosters use motors which are modified versions of the Castor 4A-XL motor design. These motors are long and roughly in diameter.

Castor 30

The CASTOR 30 motor is based on the CASTOR 120 motor, which has flown on the Taurus I, Athena I and Athena II launch vehicles. The inaugural flight of the new motor occurred in April 2013 as the second stage on the

Orbital Sciences Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...

Antares Antares is the brightest star in the constellation of Scorpius. It has the Bayer designation α Scorpii, which is Latinisation of names, Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by ...

medium-lift rocket for International Space Station resupply missions. : The CASTOR 30 upper stage measures in length and in diameter, and it weighs . The motor is nominally designed as an upper stage that can function as a second or third stage as well, depending on the vehicle configuration. : The CASTOR 30XL solid rocket motor measures in length and in diameter, and it weighs approximately . The nozzle is eight feet long with a submerged design with a high performance expansion ratio (56:1) and a dual density exit cone.

Castor 120

:An unrelated development to the earlier Castor 1, 2 and 4, the Castor 120 is a derivative of the first-stage motor of the MX ("Peacekeeper") missile. "120" refers to the planned weight, in thousands of pounds, of the booster at project inception. The actual product turned out lighter than this, however. It was first used as the first-stage motor of Lockheed Martin's Athena I, and later the first and second stages of Athena II. After a test launch in August 1995, the first launch of a customer payload took place on August 22, 1997, when an Athena was used to launch the NASA Lewis satellite. In 2006

Orbital Sciences Corporation Orbital Sciences Corporation (commonly referred to as Orbital) was an American company specializing in the design, manufacture, and launch of small- and medium- class space and launch vehicle systems for commercial, military and other governmen ...

agreed to pay $17.5 million for the Castor 120 motors used in the Taurus XL launch vehicles for the Orbiting Carbon Observatory and Glory satellites. The main solid rocket boosters ( SRB-A) of the Japanese

launch vehicle are based on the Castor 120, and were jointly designed by ATK and IHI Aerospace.

Proposed versions - based on Space Shuttle SRB

Instead of using a D6AC steel case and PBAN binder like the Space Shuttle SRB, these will use the technology derived from the GEM motors which have carbon composite cases and HTPB binder. The carbon composite design eliminates the factory joint common on all Space Shuttle SRBs.

Castor 300

: The CASTOR 300 motor is a proposed booster based on the

Space Shuttle Solid Rocket Booster The Space Shuttle Solid Rocket Booster (SRB) was the first solid-propellant rocket to be used for primary propulsion on a vehicle used for human spaceflight. A pair of them provided 85% of the Space Shuttle's thrust at liftoff and for the first ...

and was intended to be used as the second stage of the

OmegA Omega (, ; uppercase Ω, lowercase ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and last letter in the Greek alphabet. In the Greek numerals, Greek numeric system/isopsephy (gematria), it has a value ...

. The inaugural flight of the new motor was suggested to occur as soon as 2021. : Based on a 1-segment Space Shuttle SRB, the Castor 300 measures in length and in diameter, and it weighs approximately .

Castor 600

: The CASTOR 600 motor is a proposed booster based on the

and was intended to be used as the first stage of the

's small configurations. The inaugural flight of the new motor was suggested to occur as soon as 2021. : Based on a 2-segment Space Shuttle SRB, the Castor 600 measures in length and in diameter, and it weighs approximately .

Castor 1200

: The CASTOR 1200 motor is a proposed booster based on the

and was intended to be used as the first stage of the

's heavy configuration. The inaugural flight of the new motor was suggested to occur in the 2020s. It has also been proposed to replace the 5 segment RSRMVs on the Block 2

Space Launch System The Space Launch System (SLS) is an American Super heavy-lift launch vehicle, super heavy-lift Expendable launch system, expendable launch vehicle used by NASA. As the primary launch vehicle of the Artemis program, Artemis Moon landing progra ...

. : Based on a 4-segment Space Shuttle SRB, the Castor 1200 measures in length and in diameter, and it weighs approximately .

References

{{Use American English, date=January 2014 Rocket stages Solid-fuel rockets Alliant Techsystems