Algol (rocket stage)

This rocket design started as the Polaris test motor, 31 feet in length with a {{convert|40|in|m}} diameter steel case,{{Cite web |title=Algol |url=http://www.astronautix.com/a/algol.html |access-date=2025-06-17 |website=www.astronautix.com}} and 86,000 lbf of thrust.

The eventual UGM-27 Polaris A-1 was larger, {{convert|28.5|ft|m}} in length and {{convert|54|in|m}} in diameter.{{cite web|title=Polaris A1|date=May 30, 1997|url=https://nuke.fas.org/guide/usa/slbm/a-1.htm|publisher=Federation of American Scientists|access-date=April 1, 2023}}

The Algol 1 was first used for a successful suborbital launch of a Scout X-1 rocket on September 2, 1960.{{cite web | url = http://www.tbs-satellite.com/tse/online/lanc_scout.html | title = TSE – Scout | publisher = The Satellite Encyclopedia}} The rocket started as a UGM-27 Polaris test motor with a 40-inch diameter, the largest solid motor ever tested at the time. It had a nominal performance rating of 40 seconds duration and 45,000 kgf thrust. It was {{convert|19.42|ft|m}} long, {{convert|2.6|ft|m}} in diameter.{{cite web|title=Algol-1|url=http://www.astronautix.com/a/algol1.html|website=astronautix.com|access-date=April 1, 2023}} Later versions for Scout D scaled to {{convert|1.14|m|in|abbr=on}} in diameter.

These are the basic specifications for the Algol 1 engine:

• Gross mass: 10,705 kg (23,600 lb)
• Unfuelled mass: 1,900 kg (4,100 lb)
• Height: 9.12 m (29.92 ft)
• Diameter: 1.01 m (3.31 ft)
• Thrust: 470.90 kN (105,863 lbf)
• Specific impulse: 236 s
• Specific impulse sea level: 214 s
• Burn time: 40 s

Used on the Scout X (Cub Scout) test flight flown April 18, 1960.{{Cite web |title=Scout (Algol-1, -2 based) |url=https://space.skyrocket.de/doc_lau/scout.htm |access-date=2025-06-17 |website=Gunter's Space Page |language=en}} served as prototype vehicle for eventual Scout rocket.

Used on Scout X-1, RM-89 Blue Scout I, and RM-90 Blue Scout II.

Used on the Scout X-1A. After this single flight, the Scout X-2 with Algol 1-D replaced this prototype.

It was first used on the Scout X-2 on March 29, 1962. It continued to be used on Scout X-2 and Scout X-2M launches until 1963. The same year, it was also used on the Little Joe II Qualification Test Vehicle.

Image:Apollo- Little Joe II Liftoff (December 8, 1964) - cropped.jpg

These are the basic specifications for the Algol 1-D engine:{{Cite web |title=Algol 1D |url=http://www.astronautix.com/a/algol1d.html |access-date=2025-06-17 |website=www.astronautix.com}}

• Gross mass: {{convert|10,700|kg|lb|abbr=on}}
• Unfuelled mass: {{convert|1,200|kg|lb|abbr=on}}
• Height: {{convert|9.40|m|ft|abbr=on}}
• Diameter: {{convert|1.02|m|ft|abbr=on}}
• Thrust: 440.00 kN (98,910 lbf)
• Burn time: 44 s

Image:ScoutB annotated.svg

The Algol 2 (Algol II) series was first flown in 1962. It was used a first stage on Scout A, Scout B, Scout X-3 and Scout X-4.

Algol II was proposed as a strap-on motor for the 3BAS2 configuration of Titan 3B rocket proposed by Martin in the mid-1960s. It would have been used for deep space missions with a Centaur upper stage and strap-on for liftoff thrust augmentation. It was never flown. It was also proposed for the Athena RTX program in 1969, losing to Thiokol.

The Algol II-A was introduced in 1963 using the Aerojet 40 KS motor. It first flew on Scout X-3 in 1963.

The Algol II-B was created after an Algol II-A flight failure, the nozzle was designed and designate the II-B model. It first flew on Scout X-4.

These are the basic specifications for the Algol II-B engine:{{Cite web |title=Algol 2B |url=http://www.astronautix.com/a/algol2b.html |access-date=2025-06-17 |website=www.astronautix.com}}

• Gross mass: 10,700 kg (23,500 lb)
• Unfuelled mass: 1,170 kg (2,570 lb)
• Height: 9.10 m (29.80 ft)
• Diameter: 1.02 m (3.34 ft)
• Thrust: 400.00 kN (89,920 lbf)
• Burn time: 80 s

The Algol II-C flew on Scout A-1 and B-1. Scout A-2, B-2, C and 2 versions planned for Algol II-C were never used.

These are the basic specifications for the Algol II-C engine:{{Cite web |title=Algol 2C |url=http://www.astronautix.com/a/algol2c.html |access-date=2025-06-17 |website=www.astronautix.com}}

• Gross mass: 10,800 kg (23,800 lb)
• Unfuelled mass: 1,200 kg (2,600 lb
• Height: 9.10 m (29.80 ft)
• Diameter: 1.02 m (3.34 ft)
• Thrust: 436.00 kN (98,016 lbf)
• Burn time: 76 s

• UGM-27 Polaris
• Graphite-Epoxy Motor
• Little Joe
• Scout (rocket family)
• Vega (rocket)

{{Reflist}}

{{Scout rockets}}

{{Suborbital rocket engines}}

Category:Rocket stages

Category:Solid-fuel rockets