MSCText Version of this page Military Sealift Command
Fact Sheet

U.S. Navy's Military Sealift Command
Fact Sheet
June 2001

Missile Range Instrumentation Ships - T-AGM

Description: Military Sealift Command operates two missile range instrumentation ships, USNS Observation Island (T-AGM 23) and USNS Invincible (T-AGM 24). Missile range instrumentation ships provide platforms for monitoring missile launches.

Features: USNS Observation Island operates worldwide, monitoring compliance with strategic arms treaties and supporting U.S. military weapons test programs. Observation Island carries an Air Force shipborne phased-array radar system for collecting data on missile tests. The ship is operated by Military Sealift Command for the U.S. Air Force Technical Applications Center at Patrick Air Force Base, Fla.
Invincible provides a platform for a dual-band radar developed by the U.S. Air Force to support data collection requirements on theater ballistic missiles.

Background: USNS Observation Island was built as a "Mariner" class merchant ship, launched in August, 1953, and was acquired by the Navy in September 1956 for use as a fleet ballistic missile test ship. The vessel was converted at Norfolk Naval Shipyard, and kept in reserve as a Maritime Administration asset from 1972 until 1977. In August 1977, Observation Island was reacquired by the U.S. Navy and transferred to Military Sealift Command, where it was reclassified as T-AGM 23, a missile range instrumentation ship.
USNS Invincible, a converted T-AGOS-1-class ship, was redesignated a missile range instrumentation ship in April 2000. Invincible provides a platform for a dual-band radar developed by the U.S. Air Force to support data collection requirements on theater ballistic missiles.

Point of contact:
   Public Affairs Office
   Military Sealift Command
   914 Charles Morris Court SE
   Washington Navy Yard, D.C. 20398-5540
   (202) 685-5055 or www.msc.navy.mil

General Characteristics: Observation Island Class
Builder: New York Shipbuilding
Conversion: Maryland Shipbuilding and Drydock Corporation
Power Plant: Two boilers; 1 GE turbine; 19,250 hp (14.36 MW); 1 shaft
Length: 564 feet
Beam: 76 feet
Displacement: 13,060 long tons (13,269.59 metric tons) light; 17,015 long tons (17,288.06 metric tons) full load
Speed: 20 kts (23 mph)
Ship: No homeport assigned
   USNS Observation Island (T-AGM 23)
Crew: 65 civilians, 20 Navy personnel, 35 technicians

General Characteristics: Invincible Class
Builder: Tacoma Boatbuilding, Tacoma, Wash.
Conversion: Detyens Shipyard, Charleston, S.C.
Power Plant: four diesel generators, two shafts, 3,200 brake horsepower
Length: 224 feet
Beam: 43 feet
Displacement: 2,285 tons full load
Speed: 11 knots
Ship: No homeport assigned
   USNS Invincible (T-AGM 24)
Crew: 18 civilian mariners and 11 sponsor personnel

Fact Sheet Index...

This is an Official U.S. Navy Web site and is the official web site of the Military Sealift Command. For more information on employment with the Navy, visit Navy Jobs. MSC reports to Fleet Forces Command and is one of three component commands reporting to the U.S. Transportation Command, known as USTRANSCOM.