The Castor family of

solid-fuel rocket A solid-propellant rocket or solid rocket is a rocket with a rocket engine that uses solid propellants (fuel/oxidizer). The earliest rockets were solid-fuel rockets powered by gunpowder; they were used in warfare by the Arabs, Chinese, Persia ...

stages and boosters built by

Thiokol Thiokol (variously Thiokol Chemical Corporation(/Company), Morton Thiokol Inc., Cordant Technologies Inc., Thiokol Propulsion, AIC Group, ATK Thiokol, ATK Launch Systems Group; finally Orbital ATK before becoming part of Northrop Grumman) was ...

(now

Northrop Grumman Northrop Grumman Corporation is an American multinational aerospace and defense technology company. With 90,000 employees and an annual revenue in excess of $30 billion, it is one of the world's largest weapons manufacturers and military tech ...

) and used on a variety of

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload ( spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and sys ...

s. They were initially developed as the second-stage motor of the

Scout rocket The Scout family of rockets were American launch vehicles designed to place small satellites into orbit around the Earth. The Scout multistage rocket was the first orbital launch vehicle to be entirely composed of solid fuel stages. It was also t ...

. The design was based on the

MGM-29 Sergeant The MGM-29 Sergeant was an American short-range, solid fuel, surface-to-surface missile developed by the Jet Propulsion Laboratory. The missiles were built by Sperry Utah Company. The Sergeant was the third and last in a series of JPL rockets for ...

, a

surface-to-surface missile A surface-to-surface missile (SSM) or ground-to-ground missile (GGM) 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 ins ...

developed for the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, ...

at the

Jet Propulsion Laboratory The Jet Propulsion Laboratory (JPL) is a Federally funded research and development centers, federally funded research and development center and NASA field center in the City of La Cañada Flintridge, California, La Cañada Flintridge, California ...

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 non, Þórr ) is a prominent god in Germanic paganism. In Norse mythology, he is a hammer-wielding god associated with lightning, thunder, storms, sacred groves and trees, strength, the protection of humankind, hallowing, ...

first stages, including the Delta-D. (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 geosynchronous orbit in altitu ...

.) 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-built Thor first stage and the Lockheed-built Agena second stages. They are thus cousins of the more-famous Thor-Deltas, which founded the Delta rocke ...

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, and for the Japanese-built N-I,

N-II N-II was the former name for the Route Nacional from Madrid Madrid ( , ) is the capital and most populous city of Spain. The city has almost 3.4 million inhabitants and a metropolitan area population of approximately 6.7 million ...

and

H-I The H–I or H–1 was a Japanese liquid-fuelled carrier rocket, consisting of a licence-produced American first stage and set of booster rockets, and all-Japanese upper stages. The H in the name represented the use of liquid hydrogen fuel in the ...

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. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 va ...

, Atlas IIAS, and

Athena Athena or Athene, often given the epithet Pallas, is an ancient Greek goddess associated with wisdom, warfare, and handicraft who was later syncretized with the Roman goddess Minerva. Athena was regarded as the patron and protectress of v ...

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 SAIC Maxus Automotive Co., Ltd. trading as Maxus and sometimes known by the pinyin transcription of its Chinese name, Datong (大通) is a Chinese vehicle brand. Currently, it is a commercial and passenger vehicle manufacturer being a wholly ...

Programme, with launches from

Esrange Esrange Space Center (short form Esrange) 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 au ...

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 o ...

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, defense, and sporting goods company with its headquarters in Arlington County, Virginia, in the United States. The company operated in 22 states, Puerto Rico, and other countries. ATK's ...

. These boosters use motors which are modified versions of the Castor 4A-XL motor design. These motors are 38 feet long and approximately 40 inches 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 Latinised to Alpha Scorpii. Often referred to as "the heart of the scorpion", Antares is flanked by σ Scorpii and τ ...

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 The Athena II is an American small expendable launch system which was used for three launches between 1998 and 1999, and which was scheduled to return to service in 2012 but has not been flown again . It is a member of the Athena family of rocket ...

. 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

Minotaur-C Minotaur-C (''Minotaur Commercial''), formerly known as Taurus or Taurus XL, is a four stage solid fueled launch vehicle built in the United States by Orbital Sciences (now Northrop Grumman) and launched from SLC-576E at California's Vande ...

launch vehicles for the

Orbiting Carbon Observatory The Orbiting Carbon Observatory (OCO) is a NASA satellite mission intended to provide global space-based observations of atmospheric carbon dioxide (). The original spacecraft was lost in a launch failure on 24 February 2009, when the payload f ...

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 , formerly known as , is a Japanese engineering corporation headquartered in Tokyo, Japan that produces and offers ships, space launch vehicles, aircraft engines, marine diesel engines, gas turbines, gas engines, railway systems, turbochargers f ...

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 A gemstone (also called a fine gem, jewel, precious stone, or semiprecious stone) is a piece of mineral crystal which, in cut and polished form, is used to make jewelry or other adornments. However, certain rocks (such as lapis lazuli, opal, an ...

motors which have carbon composite cases and

HTPB Hydroxyl-terminated polybutadiene (HTPB) is an oligomer of butadiene terminated at each end with a hydroxyl functional group. It reacts with isocyanates to form polyurethane polymers. HTPB is a translucent liquid with a color similar to wax paper ...

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 these 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 (; capital: Ω, lowercase: ω; Ancient Greek ὦ, later ὦ μέγα, Modern Greek ωμέγα) is the twenty-fourth and final letter in the Greek alphabet. In the Greek numeric system/ isopsephy ( gematria), it has a value of 800. The ...

. 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 expendable launch vehicle developed by NASA. As of 2022, SLS has the highest payload capacity of any rocket in operational service, as well as the greatest liftoff thrust of any ...

. : 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