Martlet 3B
Launch vehicle · Canada
Original archive entry. The text, images and links below are kept as they were written.

Martlet 3A in its sabot. Martlet 3B was similar.
Canadian sounding rocket. Once the fundamental design flaws of the Martlet 3A vehicle were identified the system was redesigned and a new vehicle, the Martlet 3B, was created.
The Martlet 3B vehicle was similar in design to the 3A vehicle but sported several design changes intended to improve the system performance. The first major change was to replace the aluminum airframe with a alloy steel airframe in the hopes the stronger material would lead to higher mass fractions. Other improvements included the use of a larger diameter rocket motor (increasing the outer diameter to 8 inches / 20 cm) and the use of six fixed fins instead of the 3A's four fins.
The Martlet 3B was used to test a wide variety of variations in rocket motor types and launch techniques in order to fully explore the dynamics of sub-caliber gun-launched rockets. This included shear loading and hydraulic loading techniques, the use of radial and end burning rocket motor grains, as well as the use of composite and extruded propellants produced by four different agencies. Unfortunately there was no major improvement in the vehicle performance over the Martlet 3A in terms of vehicle mass fraction or the structural performance during the gun launching.
The last test flights of the Martlet 3B were performed in mid-1964 after which no further work was performed by HARP on sub-caliber gun-launched rocket vehicles.
by Richard K Graf
Related
- Family
- Gun-launched
- Country
- Canada
- Launch Sites
- Barbados HARP gun 16 inch
- Agency
- Bull
Photo Gallery

Project HARP 16 inch
Used with permission of Stephen E. Mendes - visit his Barbados Photo Gallery
Credit: © Stephen E. Mendes
Chronology
25 events
1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 Jul
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 July 23
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 July 23
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 July 23
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.1964 July 25
Launch Site: Barbados Site. Launch Complex: Barbados HARP gun 16 inch. LV Family: Martlet. Launch Vehicle: Martlet 3B.- 3B VI-10 - . Nation: Canada. Agency: HARP. Apogee: 80 km (49 mi). Last test flight of the Martlet 3B. Thereafter no further development work was performed by HARP on sub-calibre gun-launched rocket vehicles..