What is a missile power supply?
Missiles are fundamentally a single use product that spends the majority of its life in storage. While the launch platform may be used multiple times, they too spend the majority of their service life in storage. Military systems all have one thing in common however, their power systems need to be dependable no matter whether the usage is single or multi-use.
A missile power supply needs to work without fault and as such is designed to MIL-STDs to ensure that it can withstand extreme conditions during the launch and flight of the missile. Currently this is becoming and ever important concern as missiles get faster. Recently Russia tested its hypersonic ramjet nuclear missiles, launched off a naval ship. These were so fast that their aerials ablate and disintegrate during the first few seconds of flight.
The benefits of these new faster missiles are that they cannot be stopped by current defenses and will hit a target across the other side of the world before ICBNs can launch. The good news is that although unstoppable when the areal fails the missile needs to calculate its expected location in real-time during flight with no closed-loop system relaying back errors in the calculation. This means that these missiles at present can easily miss a target however as they are small and multiple missiles can be launched from mobile platforms it is none the less a little daunting.
So, what does a missile power supply need to withstand?
If you divide the life up of a missile, it needs to survive; manufacture, storage, service life, launch and operational life. To ensure it survives these stages of its life we need to consider the service life of the missile power supply systems in terms of the corresponding components that they are made from at the manufacturing stage and where most failures occur. If one of the many hundreds of components fall outside of manufacturing tolerance they may fail at an early stage of the products life. To reduce this risk their product is ‘soak tested’ at extreme loads over a percentage time of the service of the product in service. If the product does not fail at this stage, it is unlikely to fail prematurely in service and instead has only a greater risk failing during its end of life. A good example is aerospace engines being run at full power for a period of time before the engine is shipped to the aircraft assembly plant.
Missile power supply systems are also tested in a similar manner giving confidence that the product will work as intended during a launch. Systems may either be designed with redundant systems to ensure the product works or based on a lean system that also reduces the risk of failure through a simpler design.
While storage and logistics to the launch platform is fairly conventional for all freight extreme conditions such as shock pressure changes, temperature and humidity extremes are some of the core tests that a missile power supply must withstand. For instance, if a plane experiences explosive decompression on the way to launch platform it must be able to withstand this, as there are no in-depth checks after leaving the manufacturing plant that can be done to check the system.
Once installed the missile system is then left for the service life of the product and after this period replaced to reduce an increased risk of failure or with newer technology. During launch extreme shock in terms of shear forces, resonance of structures and components need to have been considered in the design along with the flight time at extreme acceleration and altitude changes along with temperature. This means that a warming circuit may be added and managed by the telemetry system. If the missile power supply systems are designed well with consideration of all of these aspects in the missiles service life, then there is a lower potential for failure.
