It looks like a little missile, complete with fins, and its job is to keep an aircraft out of trouble.

It is a towed decoy for the F/A-18 Super Hornet aircraft — the fighter plane that flies off of U.S. Navy carriers.

As an aircraft pulls the decoy along, it emits radio signals to confuse incoming missiles on where the target actually is. At first the decoy attempts to jam the signals of a targeting radar. If that doesn’t work, the decoy tries to fool an incoming missile that the decoy — traveling well behind the aircraft — is in fact the right target.

The fighter aircraft sends signals to the decoy via light traveling through a fiber-optic line.

The Pentagon announced Dec. 14 that it awarded BAE Systems a $19.7 million order for 253 decoys, which have the ungainly name of AN/ALE-55. The deal includes logistics and engineering technical support. BAE bases the program in New Hampshire, but 5 percent of the program (or $1 million worth of work) will be performed in San Diego, according to the Pentagon.

Work will run through December 2018.

NAVAIR, the Naval Air Systems Command of Patuxent River, Md., awarded the deal.