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On this day – April 21

Posted on April 21, 2025March 29, 2025 By Barb Sande

The events on this day in history for our heritage companies are noted below.

The earliest event was in 1966, the latest event was in 1996

Two milestone events (5 to 65+ years ago)

Human Spaceflight:

1969 – Space Shuttle Task Group formed at NASA HQ

Military and Classified Programs:

NONE

Exploration and Interplanetary Programs:

NONE

Earth-Monitoring and Civil Weather Satellite programs:

NONE

Commercial Programs:

NONE

Test, ICBM, FBM programs:

1966 – LAUNCH (3): Lockheed Polaris A3, SSBN643, ETR

1970 – LAUNCH (6): Lockheed Polaris A2, SSBN608, ETR – MILESTONE: 55 years ago

1978 – Undersecretary of Defense asks for a study to determine if a common missile could replace MM M-X and Lockheed Trident II

1980 – LAUNCH (4): Lockheed Poseidon C3, SSBN656, ETR – MILESTONE: 45 years ago

1996 – LAUNCH (2): LM Trident D-5, SSBN738, ETR

Other:

NONE

The photo today is an example of a Trident D-5 Fleet Ballistic Missile test (not one that was launched on this day).  On this particular day in history there were 15 test launches of various Fleet Ballistic Missiles, including Polaris A3 (3), Polaris A2 (6), Poseidon C3 (4), and Trident D-5 (2). 

Here is the information and credit for the photo:

151107-N-ZZ999-001 PACIFIC OCEAN (Nov. 7, 2015) A trident II D-5 ballistic missile is launched from the Ohio-class ballistic missile submarine USS Kentucky (SSBN 737) during a missile test at the Pacific Test Range. The launch, the 156th successful test flight of an unarmed Trident II D5 missile, was part of a Demonstration and Shakedown Operation (DASO) in the Pacific Test Range to validate the readiness and effectiveness of an SSBN’s crew and weapon system. (U.S. Navy photo/Released)

April 21 – An example of a Trident D-5 FBM test launch. Photo Credit: See text
On This Day

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