Castor

byJean-Jacques Serra

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Castor 1 & 2

The Thiokol Castor booster, used since 1960 as second stage forScoutwere derived from the tactical Sergeant missile. This missile, built by Sperry,was 10.6 m long for 79 cm diameter and weighed 4.5 tons. Its range was: 45 to140 km.
The Castor 1 was used by all theScout-Xversion and was replaced my Castor 2 (TX354-3) whenScout-A1was introduced in 1965.

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Castor

Designation	Length(m)	Diameter(m)	Mass(t)	Mainengine Thrust (kN)	Mainengine SI (sec.)
Castor1 (TX33)	5.92	0.79	3.85	286	27.4
Castor2 (TX354)	5.96-6.27	0.79	4.32-4.42	259-275	37
Castor4 (TX526)	9.07	1.02	10.53	428	53.9
Castor4A (TX780)	8.09-920	1.02	11.58	436-476	53.1
Castor4B (TX859)	8.98	1.02	11.48	429	60.9

From 1963 on, theThorfirst-stage-based launchers were equipped with Castor solid boosters to get theTAT (Thrust Augmented Thor). TheTAT Agenawas launched in 1963, theTAT Delta(or TAD) in 1964. Those Castor-1 & Castor-2 boosters were then used bygroups of 3, 6 (Delta M6) and finally 9 (Delta 900). The last models were usedfrom 1975 on by the JapaneseN1, N2 and H1 rockets.

The boosters of Sergeant missiles are still used by OSC for Starbird (targetsfor the ERINT program), LCLV (Low Cost Launch Vehicle) and Storm (targets forthe THAAD program).

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Castor 4 & 4A

After 1975, when the only Thor first stage-based was theDelta(3900 series) the Castor-2 were replaced by Castor-4 (TX526) of 1.02 m diameterthat we herited from the Athena-H sounding rocket. In 1989 an enhanced versionwas introduced on theDelta 2(6900 series): Castor-4A (TX780) weighing 11.6 tons. Two pairs of Castor-4Aboosters also equip theAtlas 2(2AS version) since 1993.

The light launcherConestogawas designed from associated Castor-4. The most powerful version, Conestoga1620, is made of 6 Castor-4 (4 Castor-4B with deployable nozzle and 2 Castor-4Awith fixed nozzle) surrounding a Castor-4B. Four Castors are fired at launchtime (1st stage), 2 are ignited then (2nd stage) and the central Castor-4 actsas the third stage. The top stage is a Star-48, also built by Thiokol.

The Castor-4A boosters are also used by OSC for Prospector sounding rocketssince 1991. The Maxus rocket (German & Swedish) is the largest soundingrocket fired from Europe (Kiruna). It is also made of a Castor-4B; with 12.3tons and 500 kg payload.

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Castor 120 GT

The Castor-120 is a large solid fuel booster derived from the MXPeacekeeper (TU 903) missile. This booster is 8.89 m long and 2.34 m diameter.It weighs about 54 tons. Castor-120 was modified to provide a smalleracceleration than the TU 903: 1546 kN (in vacuum) during 86 seconds.

Two light launchers are based on it:Taurusfrom OSC (with the 3 Hercules stages ofPegasus)andAthenafrom LM (with an Orbus 21 UTC/CSD).

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