Spice (bomb)

Introduction

The "Spice" munition is more advanced than most EO-guided bombs (GBU-15, for example), since it combines the advantages of satellite guidance (such as the ability to engage camouflaged and hidden targets; to provide a "drop-and-forget" option for several such targets simultaneously; and to operate in all weather and lighting conditions) and those of electro-optical guidance (such as the ability to provide "man-in-the-loop" guidance for extremely high precision; the ability to engage relocatable targets; lower CEP than that of satellite-guided munitions; and independence from external information sources like satellites) into one bomb – reducing the amount of munitions (and hence, payload) that an aircraft has to carry for a given strike mission, increasing its combat radius and maneuverability. This multiple guidance methods selectability is especially important in an "information warfare" battlefield, where an aircraft might approach a surface target while it is, for example, masked with smoke (in which case satellite guidance would be required) or moving around (in which case electro-optical guidance would be required).

Another advantage of the "Spice" is its ability to be fed, preflight, with up to 100 different targets it may have to engage. The one target it will actually engage may then be selected, inflight, by an aircrewman.

Since it has a total of 12 control surfaces in 3 groups (fore, mid-body and tail), the "Spice" has a very long glide range, of about 60 kilometers. This allows a striking aircraft to release a bomb at a target without entering the threat envelope of most short- and medium-range air defense systems which might protect it. This is achieved while saving the higher costs associated with propelled munitions.

Specifications

Variants

Operation

On the ground, an unguided bomb is fitted with a "Spice" guidance kit.

Still on the ground, each bomb's memory may be loaded with up to 100 different targets, complete with their image (usually acquired by imagery intelligence) and geographical coordinates.

The bomb is then loaded on a strike aircraft. In the pylon to which the bomb is attached there is a datalink between the aircraft's cockpit and the bomb.

As the aircraft flies in the air and approaches a target, either the weapon systems officer (WSO – the backseater in such aircraft as the F-15E Strike Eagle or F-16I Sufa) or pilot (in single-seat aircraft) can use the TVIIR display in the cockpit to see the image the bomb sends to him. Once he selected one of the preprogrammed targets, or fed the bomb with a target himself (by feeding it with either an image or geographical coordinates to home on), the bomb is ready for release into a guided trajectory.

Once the bomb is released, it begins searching its target in order to acquire it and home on it. This can be done in several ways:

First, there is pure CCD or IIR (for low lighting conditions) image matching, when the guidance section uses algorithms in order to match the target image in its memory with the image provided by the seeker, and align the center of the seeker's FOV with the desired image (guidance method known as DSMAC).

Second, if the CCDIIR seeker can not acquire its target for any reason (such as visual obstructions), the bomb can automatically switch to GPSINS guidance. This means that the bomb aspires to bring itself to the target's altitude at a known geographical location. The bomb receives data on its current location from GPS satellites, or from an inertial navigation system in the bomb itself, that has been fed, through the pylon datalink, with the dropping aircraft's coordinates a fraction of a second before drop, and can therefore calculate its own coordinates from the dropping time and on.

Third, there is a manual "man-in-the-loop" guidance option, in which the WSO looks at a backseat TV display in order to see the seeker's view (sent to him through a RF command guidance datalink) and uses the backseat stick to control the bomb all the way to the target. With a skilled WSO that has a "sensitive hand", this guidance method is probably the most accurate one employed today for air-dropped munitions, and has no measurable miss distance. Its main drawback is that it allows for only one bomb to be guided at a time.

Disadvantages

The main disadvantage of the "Spice" ammunition is its high cost relative to GPS-guided munitions. Although many air-to-ground scenarios may indeed require the EO guidance option, many others do not, and can be completed successfully while using just GPS guidance kits such as the AGM-154 Joint Standoff Weapon, at a fraction of the cost of the "Spice".

Comparable systems

The Israeli "Spice" is comparable to the American GBU-15, which also combines EO and GPS guidance and can be fitted to a variety of warheads.