Hypergolic Propellant - Use in ICBMs

Use in ICBMs

The earliest ballistic missiles, such as the Soviet R-7 that launched Sputnik 1 and the US Atlas and Titan-1, used kerosene and liquid oxygen. Although they are preferred in space launchers, the difficulties of storing a cryogen like liquid oxygen in a missile that had to be kept launch ready for months or years at a time led to a switch to hypergolic propellants in the US Titan II and in most Soviet ICBMs such as the R-36. But the difficulties of such corrosive and toxic materials, including leaks and explosions in Titan-II silos, led to their near universal replacement with solid-fuel boosters, first in Western submarine-launched ballistic missiles and then in land-based US and Soviet ICBMs.