Algol (rocket stage)

The Algol family of solid-fuel rocket stages and boosters is built by Aerojet (now Aerojet Rocketdyne) and used on a variety of launch vehicles. It was developed by Aerojet from the earlier Jupiter Senior and the Navy Polaris programs. Upgrades to the Algol motor occurred from 1960 until the retirement of the Scout launch vehicle in 1994.

The Algol family use solid propellant fuel with a loaded mass of 10,705 kg, and produces 470.93 kN of thrust. The motor has a specific Impulse of 236 seconds in a vacuum environment. Variations Algol I, I-D, II, II-A, II-BA popular rating was 40KS-115,000 (52,000 kgf for 40 seconds), also known as Senior.

They were initially developed as the first-stage of propulsion for the Scout rocket, with the design being based on the UGM-27 Polaris, a submarine-launched ballistic missile developed for the United States Navy at the Jet Propulsion Laboratory.

This rocket design started as the Polaris test motor, 31 feet in length with a 40 inches (1.0 m) diameter steel case, and 86,000 lbf of thrust. The eventual UGM-27 Polaris A-1 was larger, 28.5 feet (8.7 m) in length and 54 inches (1.4 m) in diameter.

The Algol 1 was first used for a successful suborbital launch of a Scout X-1 rocket on September 2, 1960. 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 19.42 feet (5.92 m) long, 2.6 feet (0.79 m) in diameter. Later versions for Scout D scaled to 1.14 m (45 in) in diameter.

These are the basic specifications for the Algol 1 engine:

Used on the Scout X (Cub Scout) test flight flown April 18, 1960. served as prototype vehicle for eventual Scout rocket.

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