On Friday, the Department of Defense announced that it has awarded Alliant Techsystems (UNKNOWN:ATK.DL) a $20 million firm-fixed-price contract modifying an existing contract to supply Spider munitions control units, or MCUs.

The XM-7 Spider is a so-called "man-in-the-loop" networked anti-personnel "munitions system" -- a.k.a. a land mine -- developed jointly between Alliant and fellow defense contractor Textron (NYSE:TXT) -- with yet another defense company, General Dynamics (NYSE:GD), sometimes serving as a prime subcontractor. It consists of a remote-control station, or RCS, controlling up to 84 MCUs, which in turn contain six grenades each -- meaning each system can contain more than 500 munitions.

Through use of the RCS, a controller alerted that an MCU has been "tripped" can choose to detonate all, some, or none of the MCU's grenades. The RCS can also be used to detonate MCUs after the end of hostilities, eliminating the threat that unexploded landmines will remain in a country after the conclusion of a war. An MCU's grenades can contain lethal ordnance, or non-lethal.

Each MCU is said to cost approximately $5,000, suggesting that the current contract modification appears to be requisitioning the supply of some 4,000 MCUs. It is supposed to be completed by November.