By Samantha Masunaga / Los Angeles Times

WASHINGTON — In a contest to build the first drone that will fly alongside Navy carrier fighters, the Boeing Co. has won a contract worth up to $805 million to build aerial refueling tankers, the Pentagon said Thursday.

Most of the work on the tanker drones, known as the MQ-25A Stingray, will be done in St. Louis, though 1.5 percent will be completed in San Diego, according to the Defense Department’s contract listing. Boeing will receive $79 million of the total award amount to start.

The MQ-25 will be launched via catapult from the decks of aircraft carriers. The initial contract is for four aircraft, but the Navy said it eventually plans to spend $9.5 billion to produce 72 tankers. The first four drones are set to become operational by 2024.

Lockheed Martin Corp. and General Atomics were also competing for the contract. Both companies had been doing much work on their contending designs in Southern California, Lockheed Martin at its famed Skunk Works unit in Palmdale and General Atomics at its San Diego facilities.

The aircraft that currently make up carrier air wings —the F/A-18 Super Hornet and F-35 Lightning II fighters —have relatively short ranges compared with the planes they replaced, making refueling a higher priority. Potential adversaries such as Russia and China have the ability to threaten carriers hundreds of miles out to sea. Concerns about wear and tear on Super Hornets and their crew —which currently handle refueling duties, along with fighter tasks —also prompted demand for unmanned replacements.

Boeing’s MQ-25 drone will be powered by a Rolls-Royce engine, which is also used in the U.S. Air Force’s Global Hawk and and Navy’s Triton drones.