The SWOD MK 9 "Bat" was a radar-guided missile that was built by the United States during World War II. It lacked rocket propulsion, and instead was designed as a glide bomb that was deployed from an aircraft. This long range radar antenna (approximately 40m (130ft) in diameter) rotates on a track to observe activities near the horizon. ... A missile (British English: miss-isle; U.S. English: missl) is, in general, a projectile—that is, something thrown or otherwise propelled. ... Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km (over 11 miles) into the air. ... A Redstone rocket, part of the Mercury program A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of fast moving exhaust gas from within a rocket engine. ...

The Bat was dropped from an altitude of 15-25,000 feet at 140-210 knots, then homed in on its target using the reflected pulses from a built-in radar transmitter. It was gyro-stablized with an auto-pilot system, and the steerable tail elevator was powered by small wind-driven generators. The Bat had a length of 11 ft. 11 in., a wing span of 10 ft., and an empty weight of 600 lbs. It was designed to carry a 1,000 lb. warhead.

The development of the Bat was led by Hugh L. Dryden of the National Bureau of Standards, which supplied the air frame. The radar was supplied by Western Electric Co., and the gyroscope by Bendix Aviation Co. Dr. Dryden was awarded the Presidental Certificate of Merit for the Bat's development. As a non-regulatory agency of the United States Department of Commerce’s Technology Administration, the National Institute of Standards (NIST) develops and promotes measurement, standards, and technology to enhance productivity, facilitate trade, and improve the quality of life. ...

When used during World War II, the Bat proved somewhat disappointing. It tended to home in on inappropriate land-based features, limiting use to targets away from land. It had only a mediocre success rate, damaging some ships and sinking one Japanese destroyer. A total of 3,000 Bats were manufactured, but most were never used. It was taken out of deployment following the war after tests revealed the radar could be relatively easily foiled by simple countermeasures. Mushroom cloud from the nuclear explosion over Nagasaki rising 18 km (over 11 miles) into the air. ... USS Lassen, an Arleigh Burke-class destroyer In naval terminology, a destroyer is a fast and manouverable yet long-endurance warship intended to escort larger vessels in a fleet or battle group and defend them against smaller, short-range attackers (originally torpedo boats, later submarines and aircraft). ...

External links

• NASM Space Artifacts
• Bureau of Standards SWOD MK 9/ASM-N-2