== Trigger Mechanisms ==

=== Pyrotechnic Cables and Bolt Cutters ===

This mechanism employs a small controlled expansion to propel a bolt towards a cable placed on an anvil. The bolt strikes the cable and cuts it, thus releasing the deployable that the cable was securing. An animation for the same can be found [http://spot4.cnes.fr/spot4_gb/images/pyro/pan.gif here].

==== Advantages ====

====Disadvantages ====

The explosion may generate a lot of internal force and create hazards for the satellite

=== Burn Wire Mechanism ===

The release mechanism utilizes a compressed spring system to ensure permanent contact with the cable that is securing a deployable. When heated the burn wire would cut through the cable due to pre-compressed spring. After a successful cut the spring extends to its natural length. Usually the burn wire is made of Nichrome, which is heated to high temperature and the cable is made of Vectran (A high strength, high thermal stability and low creep fiber)

====Advantages ====

====Disadvantages ====

May fail to cut through the wire in one shot i.e. unreliable (To tackle this, usually redundant setups are used to ensure that the mechanism works well)

=== Shape Memory Alloy (SMA) ===

[[File:SMA1.jpg|thumb]]

A SMA is an alloy that “remembers” its original shape when it was formed and returns to it from its deformed state when heated. There are multiple actuators already in use as well as several under development that exploit use of SMAs for release of the deployable. <br \>

Some of the mechanisms that use SMAs are listed:

====Disadvantages====

They are not yet tested extensively in space and are in development, some parts are too small and difficult to manufacture hence are expensive currently. Also they may be susceptible to external rise in temperature and cause untimely deployment

=== Paraffin release mechanism ===