MIL standards and specifications

The Armed Forces have many numerical designations for computers or other equipment, to guide the military buyer's choice of appropriate technology for their application. For instance, Mil-S-901D would indicate that the computer passed shock and vibration requirements of specific tests for Navy installation. Some of these tests are specific to application usage, such as barge explosion testing, which simulates a torpedo hit and subsequent high peak shock to a ship on which the computer is installed.

901D is divided into Grade A for "Items which are essential to the safety and continued combat capability of the ship" and Grade B for "items whose operation is not essential to the safety and combat capability of the ship but which could become a hazard to personnel, to Grade A items, of the ship as a whole as a result of exposure to shock".

In this way, a computer may have a rating of MIL-Std-901D Grade A, which would tell a buyer which shock tests the computer survived, what level of shock resistance the unit has, and that this piece of equipment will continue to normally operate in the event of a specific shock level.

Other MIL Standards and MIL Specs (Specifications) include testing for resistance to EMI/RFI bursts, environmental contaminants such as dust and gas, or temperature extremes. More on MIL Standards and Specifications at Defense Standard

Defense Standard

A United States defense standard, often called a military standard, "MIL-STD", "MIL-SPEC", or "MilSpecs", is used to help achieve standardization objectives by the U.S...

.

The "gold standard" of testing for compliance with 901D is the Barge Test. A Barge Test is performed four times, each time placing 60 lbs HBX-1 explosive 24 feet under water, starting at 40 feet away, then at 30, 25 and finally 20 feet. In addition, the tests are performed in a fore-and-aft orientation to simulate an explosion at the bow or stern of the ship and athwartship to simulate an explosion by the side of the ship. A video of a barge test can be viewed.

Typically a military computer is much more robust than an industrial computer enclosure. There will be more structure inside to support the components, the plug-in cards will be individually supported and secured to assure they do not pop out of their sockets, the processor and heat sink

Heat sink

A heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid. Examples of heat sinks are the heat exchangers used in refrigeration and air conditioning systems and the radiator in a car...

 will be secured, memory will be glued into their sockets, and so forth. This is to assure nothing moves during the shock events.

Field risks

The progress of small-scale computer technology in military applications was initially slow due to concerns about security and the ability to survive rugged environments and enemy weaponry. PC-based technology in the 20th century was not robust enough to withstand combat conditions and severe environments.

Hazards in the field include water and corrosives, sand and wind, extreme temperatures, high shock and vibration, power interruptions, susceptibility to EMI/RFI radiation, etc. Also, operator interface was complex, and most operating system

Operating system

An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...

s were not fast in operation, or easy to learn and use in pressure situations.

In the last decade, improvements in design and operator interface have resulted in new mandates for the use of small computer technology in the military. Some of the improvements have migrated over from home and business computing. Others have migrated over from industrial computing, where designs for environments such as Zone 1 hazardous areas

Electrical Equipment in Hazardous Areas

In electrical engineering, a hazardous location is defined as a place where concentrations of flammable gases, vapors, or dusts occur. Electrical equipment that must be installed in such locations is especially designed and tested to ensure it does not initiate an explosion, due to arcing contacts...

 in oil & gas exploration have been modified for army and navy environments.

• Sealed enclosures using materials such as cast aluminum with magnesium have improved environmental resistance to contaminants and hazards, including EMI-burst weaponry.
• Low-heat CPU
  Central processing unit
  The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
  
   designs have made sealed enclosures possible even for environments like the desert or naval bridge wing display under the open sun.
• Advances like flash memory
  Flash memory
  Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
  
   have eliminated moving parts and reduced mechanical failures.
• Simpler, effective OS software has improved the operator interface and speed of execution, while reducing OS failures.

Applications and computer type

There are many types of small computers used in the military. Recently there has been an increase in the implementation of thin client

Thin client

A thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...

 technology in many applications that don't require full computing capability. Thin client technology reduces costs and eliminates some of the risks of placing more complex computers in rugged situations.

Embedded computers are being integrated into more applications. These computers are generally fixed-function computers that are robust and bring additional capabilities to machines or complex equipment.

Notebooks and laptop

Laptop

A laptop, also called a notebook, is a personal computer for mobile use. A laptop integrates most of the typical components of a desktop computer, including a display, a keyboard, a pointing device and speakers into a single unit...

s have become more rugged since the turn of the century, and more portable computers are being placed into warfighter's hands than ever before. A number of manufacturers are specializing in creating ultra-rugged notebooks for the military. Now, some of these advances created for the military are finding their way backward into the home and business markets.

Wireless communications technology has also improved in recent years. High-speed data transferral over secure, encrypted frequencies is consider a new standard for standard-security-level communications. The new wireless radio networking devices can establish a link between systems that could otherwise not physically communicate or be involved in command and control. Some thin clients and portable computers employ these recent advances.

Future computer use in the military

In the last 20 years, wide acceptance of small-scale computer technology in the military has occurred, and is likely to increase greatly. Confidence has improved in the ability of equipment to withstand combat and extreme environment conditions. Most importantly, modern combat has become a duel of speed. We continually see that faster and more technologically advanced weaponry demonstrates first-strike capability in current combat situations, which is likely only to encourage further implementation of computer technology into systems used in the US Armed Forces in the future.