Hydrazine is a very reactive material that can decompose with incredible speed and energy under a number of conditions. Its decomposition yields exhaust products at high temperatures with low molecular weight-an ideal combination for rocket propulsion and gas generation. This decomposition is highly reliable and reproducible to within milliseconds.
Arch's Ultra Pure™, Monomethyl Hydrazine (MMH), Unsymmetrical Dimethylhydrazine (UDMH), and Anhydrous Hydrazine (AH) products are utilized in both mono-and bipropellant systems. Leading aerospace organizations such as NASA, the U.S. Air Force, PRIMEX Technologies and Kaiser Marquardt use high-quality Arch hydrazine propellants.
Monopropellant Systems
In monopropellant systems, controlled decomposition is triggered by contact with a catalyst. Literally hundreds of satellites and space probes rely on hydrazine fueled thrusters for altitude control or orbit maintenance. Such precious maneuvers require as little as a tenth of a pound of thrust…hundreds of times, over an operating lifetime of 10 to 15 years.
Monopropellant systems are also used on short-term missions. They provide altitude and roll control of boosters and upper states of expendable launch vehicles.
Bipropellant Systems
In bipropellant systems, liquid hydrazine and an oxidizer are injected simultaneously to initiate a hypergolic reaction. Such systems can help power expendable launch vehicles such as Titans, Delta and Ariane 4, as well as the Space Shuttle orbital maneuvering system and many large satellites. Bipropellant engines can generate up to a million pounds of thrust--without reliance on external ignition systems.
In some respects, the use of hydrazine as a propellant is a mature technology. Today there are many off-the-shelf boosters and thrusters using standardized blends and derivatives. Yet development continues on a variety of new and improved propellant units.
Arch Ultra Pure™ Hydrazine
The major use of Ultra Pure™ hydrazine is as a rocket propellant in monopropellant thrusters and gas generators. Most satellites in earth orbit and most space probes use hydrazine for attitude control and orbit maintenance. Other applications may be in the electronics industry.
Arch Monomethyl Hydrazine (MMH)
The major use of monomethyl hydrazine is in the aerospace industry. It is used as a propellant and for spacecraft orbital control thrusters. Monomethyl hydrazine may also be used in chemical synthesis where both an N-N bond and a methyl group are desired. Many patents have been issued covering applications of monomethyl hydrazine in petroleum refining, explosives, metal treating, photography, fibers, coatings and resins.
Arch Unsymmetrical Dimethylhydrazine (UDMH)
The major use of UDMH is in the aerospace industry, where it is primarily used as a propellant. It is also used in chemical synthesis, where an N-N bond and two methyl groups are needed (e.g. in the synthesis of photographic chemicals). It has also been used in acidic gas absorbers and as a fuel stabilizer.
Arch Anhydrous Hydrazine (AH)
The major use for anhydrous hydrazine is as a propellant and aerospace fuel. It is also recommended for applications requiring an intense, yet controllable, release of energy. For example, it is being used as a controlled explosive for fracturing underground rock formations in the secondary recovery of petroleum and natural gas. Anhydrous hydrazine may also be used in the preparation of derivatives or in reactions which require hydrazine, but which cannot tolerate the water of an aqueous solution.