Solid-fuel Rocket - History

History

Solid rockets were invented by the Chinese, the earliest versions were recorded in the 13th century. Hyder Ali, king of Mysore, developed war rockets with an important change: the use of metal cylinders to contain the combustion powder.

Castable composite solid rocket motors were invented by John Whiteside Parsons at Caltech in 1942 when he replaced double base propellant with roofing asphalt and potassium perchlorate. This made possible slow-burning rocket motors of adequate size and with sufficient shelf-life for JATO applications. Charles Bartley, employed at JPL (Caltech), substituted curable synthetic rubber for the gooey asphalt, creating a flexible but geometrically stable load-bearing propellant grain that bonded securely to the motor casing. This made possible much larger solid rocket motors. Atlantic Research Corporation significantly boosted composite propellant I_sp in 1954 by increasing the amount of powdered aluminum in the propellant to as much as 20%.

The largest solid rocket motors ever built were Aerojet's three 260 inch monolithic solid motors cast in Florida. Motors 260 SL-1 and SL-2 were 261 inches in diameter, 80ft 8in long, weighed 1,858,300 pounds and had a maximum thrust of 3.5M pounds. Burn duration was two minutes. The nozzle throat was large enough to walk through standing up. The motor was capable of serving as a 1-to-1 replacement for the 8-engine Saturn 1 liquid-propellant first stage but was never used as such. Motor 260 SL-3 was of similar length and weight but had a maximum 5.4M pounds thrust and a shorter duration.