Cold launch system comprising shape-memory alloy actuator

Abstract

A cold-launch uses shape-memory-alloy (“SMA”) actuators to accelerate materiel to a required launch velocity. The SMA actuators are arranged into one or more actuation stages. SMA actuators within a given actuation stage are simultaneously triggered. Actuation stages, however, are triggered sequentially, each triggering adding to the velocity of the materiel.

Description

FIELD OF THE INVENTION[0001]The present invention relates generally to launch systems, and more particularly to cold launch systems.BACKGROUND OF THE INVENTION[0002]A canisterized missile is typically launched using the missile's launch booster—so called “hot launch.” When the booster fires, a plume of very high-temperature, high-velocity exhaust gas is generated. The plume, which in some cases contains metallic particulates, is very erosive. Direct exposure to the plume would have an adverse effect on the missile, the missile canister, other launch structures, and the surrounding environs (e.g., deck of a ship, etc.).[0003]As a consequence, most missile-launch systems include an exhaust-gas management system, which directs the booster plume away from the missile and launch structure. To withstand the plume's extreme conditions, the launch structure, as well as the exhaust-gas management system itself, must incorporate thermal-protection and erosion-protection materials.[0004]Incorp...

AI Technical Summary

Benefits of technology

[0015]In some embodiments, the cold-launch system disclosed herein will incorporate one or more additional stages of actuators. In such a multi-stage system, SMA actuators will be organized into multiple groups that reside on separate, sequentially-arranged, individually-movable platforms. The stages are individually triggerable and, in fact, are triggered one after the other, with each triggering adding to the velocity of the load. Sequenced triggering can provide a relatively high launch velocity while remaining within g-force limitations of the load.

Problems solved by technology

Direct exposure to the plume would have an adverse effect on the missile, the missile canister, other launch structures, and the surrounding environs (e.g., deck of a ship, etc.).

Incorporation of the exhaust-gas management system and the protective materials necessarily enlarges the missile-launch system as well as increasing its weight, cost and complexity.

Furthermore, the heating of the launch structure and deck that results from hot launch creates a residual thermal signature.

This signature is readily detectable by various sensors, and therefore potentially compromises the survivability of the missile launcher and, indeed, the ship or vehicle that supports it.

Also, by its nature, hot launch technology increases the volatility of a missile due to the presence of the additional energetics, which are stored in the missile's booster.

But existing cold launch systems are not without drawbacks of their own.

One drawback is that most cold launch system include a substantial number of additional components, which raises reliability issues.

Another drawback is that in some cold launch systems, the missile is exposed to high-pressure gas from a gas generator (that provides the pressure for launch).

Also, electromagnetic launch systems require a great deal of electrical current to launch a missile.

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