The MK80 (pronounced "Mark Eighty") family is a series of unpowered
gravity bombs built for (originally) the
U.S. Air Force. They were designed for use on American tactical aircraft of the day, but as time has passed, new
platforms have been modified as necessary to ensure that this weapon could be used.
The 'family' consists of four base types:
- Mk81 - a 250-lb unit
- Mk82 - a 500-lb unit
- Mk83 - a 1,000-lb unit
- Mk84 - a 2,000-lb unit
Note that these weights are all-up, meaning a total weight for the weapon. The
Mk84, for example, contains a payload of approximately 945 lbs. of explosive (either
Compound H-6 or
Tritonal).
The main distinguishing characteristic of these weapons is their shape; the 'LDGP' stands for 'Low Drag, General Purpose.' The Mk80 family are all slim tapered cylinders. They can accept what is by this point an astonishing number of options. The most basic use is to mate the weapon with a standard tailkit, designed to simply steady its descent, and a nose or tail-mounted mechanical fuze (nose for blast, tail for cratering use).
As technology has improved, however, the Air Force found that it was remarkably easy to design more complex weapons simply as add-on kits for the Mk80 family. Seekers for the nose, coupled with maneuvering tailkits, are popular: most general purpose U.S. LGBs are built this way. Retarding kits (ballutes and/or fins) can be added to cause the bomb to rapidly lose speed, which is ideal when dropping them from a low altitude; they give the aircraft more time to escape the blast radius. Other popular versions include the newer GPS and TV/IIR guided seekers, allowing the bomb some measure of autonomy in target selection and tracking.
One of the reasons the weapon has survived is this expandability. Also, it's cheap! The basic bomb itself costs no more than around $3200 in current dollars. While the various add-on kits may drive the cost per unit into the hundreds of thousands, it makes them much easier to store, transport and produce; the sensitive parts are built and kept separately, and only mated with warheads at the last minute.
Not just tactical aircraft drop these weapons. They were (and remain) the weapon of choice for unguided area attack ('carpet bombing') by the B-52 Stratofortress, as their low cost meant they could be expended in the huge numbers required. The various sizes allow mission loads to be tailored while retaining a common logistics tail and hookup system. During Desert Storm, over 12,000 of these weapons were dropped on targets in the Iraqi TOE.
The aircraft certified to drop this weapon include: