NATIONAL HARBOR, Md. -- Northrop Grumman's (NOC) B-21 Raider isn't currently being designed to be unmanned but that capability would be a consideration in the future, the Air Force said.

The service put an unmanned option in the long-range bomber's contract criteria, though the Air Force hasn't exercised the requirement yet, Lt. Gen. Arnold Bunch, military deputy in Air Force acquisition, said at the Air Force Association's Annual Air, Space and Cyber conference Tuesday.

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IBD'S TAKE: Northrop, Boeing and Lockheed are battling for billions of Pentagon aerospace dollars as the defense aerospace market is booming on increased threats in the Middle East, Russia and South China Sea.

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Northrop beat a Boeing (BA)-Lockheed Martin (LMT) team for the B-21 contract last year to replace the Cold War-era Boeing B-52 Stratofortress.

Northrop shares rose 0.45% to close at 212.11 on the stock market today. Boeing shares edged up 0.2%. Lockheed shares fell 0.2%.

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