High test peroxide


 * "HTP" redirects here. For the internet transfer protocol, see Hypertext Transfer Protocol. For information on the "House-tree-person" test, see Psychological testing.

High test peroxide or HTP is a high (85 to 98 percent) concentration solution of hydrogen peroxide, with the remainder predominantly made up of water. In contact with a catalyst it decomposes into a high temperature mixture of steam and oxygen. It was used as a propellant of HTP rockets and torpedoes.

Catalysis
Contact with certain permanganate salts or silver or platinum are commonly used in catalyst packs.

Safety
Since many common substances catalyze peroxide exothermic decomposition into steam and oxygen, handling of HTP requires special care and equipment. Notably, iron and copper are incompatible with peroxide, both common materials.

Usage
HTP has been used safely and successfully in many applications beginning with German usage during World War II and continues to the present day. Some significant US programs include the reaction control thrusters on X-15 program. The Royal Navy experimented with HTP as the oxidiser in the experimental high-speed target/training submarines Explorer and Excalibur between 1958 and 1969.

The first Russian HTP torpedo was known by the strictly functional name of 53-57, the 53 referring to the diameter in centimetres of the torpedo tube, the 57 to the year it was introduced. Driven by the Cold War competition, they ordered the development of a larger HTP torpedo, to be fired from the 65 cm tubes.

British experiments with HTP as a torpedo fuel were discontinued after a peroxide fire resulted in the loss of HMS Sidon in 1956. British experimentation with HTP continued in rocketry research, ending with the Black Arrow launch vehicles in 1971. Black Arrow rockets successfully launched the Prospero X-3 satellite from Woomera, South Australia using HTP and kerosene fuel.

An accident involving an HTP torpedo was believed to be the cause of the Russian submarine Kursk explosion.

During World War II, high test peroxide was used as an oxidizer in some German bipropellant rocket designs, eg. Messerschmitt Me 163, where it was called T-Stoff.

It is (with concentration of 82%) still in use on the Russian Soyuz launch vehicle to drive the turbopumps on the boosters and on the orbital vehicle.

When used with a suitable catalyst, HTP can be used as a monopropellant, or with a separate fuel as a bipropellant.