The Castor 1 was first used for a successful suborbital launch of aScout X-1 rocket on September 2, 1960.[4]
It was 19.42 feet (5.92 m) long, 2.6 feet (0.79 m) in diameter, and had a burn time of 27 seconds. Castor 1 stages were also used as strap-on boosters for launch vehicles usingThor first stages, including theDelta D. (A Delta-D was used in 1964 to launchSyncom-3, the first satellite placed in ageostationary orbit.) 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-assistedThor-Agena launchers. The last launch using a Castor 1 was in 1971.[5]
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 theDelta E, and for the Japanese-builtN-I,N-II andH-I rockets. It retained the same diameter as the Castor 1, and was from 5.96 m to 6.27 m in length.
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, Atlas IIAS, andAthena RTV launch vehicles. They were also planned to serve as the first stage of the SpanishCapricornio booster, however, no such flights occurred before the project was cancelled.
Castor 4B is used in the EuropeanMaxus Programme, with launches fromEsrange in Sweden.
Certain versions of theH-IIA rockets flown byJAXA used either two or four strap-on boosters developed and produced byAlliant Techsystems. These boosters use motors which are modified versions of the Castor 4A-XL motor design. These motors are 38 feet (11.6 m) long and roughly 40 inches (1.02 m) in diameter.[6]
Castor 30 rocket motor being ground-testedThe 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 theOrbital SciencesAntares medium-lift rocket for International Space Station resupply missions.
The CASTOR 30 upper stage measures 138 inches (3.5 m) in length and 92 inches (2.3 m) in diameter, and it weighs 30,000 pounds (14,000 kg). 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 236 inches (6.0 m) in length and 92 inches (2.3 m) in diameter, and it weighs approximately 56,000 pounds (25,000 kg). The nozzle is eight feet long with a submerged design with a high performance expansion ratio (56:1) and a dual density exit cone.
A Castor 120 that was used as Stage 0 of aTaurus XL rocket for the OCO launch
An unrelated development to the earlier Castor 1, 2 and 4, the Castor 120 is a derivative of the first-stage motor of theMX ("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'sAthena I, and later the first and second stages ofAthena II.[7] 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 NASALewis satellite.[8] In 2006Orbital Sciences Corporation agreed to pay $17.5 million for the Castor 120 motors used in theTaurus XL launch vehicles for theOrbiting Carbon Observatory andGlory satellites.[9] The main solid rocket boosters (SRB-A) of the JapaneseH-IIA launch vehicle are based on the Castor 120, and were jointly designed by ATK andIHI Aerospace.[10]
Instead of using aD6AC steel case andPBAN binder like the Space Shuttle SRB, these will use the technology derived from theGEM motors which have carbon composite cases andHTPB binder.[11] The carbon composite design eliminates the factory joint common on all Space Shuttle SRBs.
The CASTOR 300 motor is a proposed booster based on theSpace Shuttle Solid Rocket Booster and was intended to be used as the second stage of theOmegA. The inaugural flight of the new motor was suggested to occur as soon as 2021.[12]
Based on a 1-segment Space Shuttle SRB, the Castor 300 measures 499.6 inches (12.69 m) in length and 146.1 inches (3.71 m) in diameter, and it weighs approximately 300,000 pounds (140,000 kg).[13]
The CASTOR 600 motor is a proposed booster based on theSpace Shuttle Solid Rocket Booster and was intended to be used as the first stage of theOmegA'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 860 inches (22 m) in length and 146.1 inches (3.71 m) in diameter, and it weighs approximately 600,000 pounds (270,000 kg).
The CASTOR 1200 motor is a proposed booster based on theSpace Shuttle Solid Rocket Booster and was intended to be used as the first stage of theOmegA'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 2Space Launch System.
Based on a 4-segment Space Shuttle SRB, the Castor 1200 measures 1,476.3 inches (37.50 m) in length and 146.1 inches (3.71 m) in diameter, and it weighs approximately 1,200,000 pounds (540,000 kg).
