Scale Model of Agena/Mariner-C in the 8- by 6-Foot Supersonic Wind Tunnel

Researcher Bobby Sanders examines a 0.10-scale model of the Mariner-C shroud and Agena rocket in the 8- by 6-Foot Supersonic Wind Tunnel at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Mariner-C and Mariner-D were identical spacecraft designed by the Jet Propulsion Laboratory to flyby Mars and photograph the Martian surface. The two Mariner spacecraft were launched by Atlas-Agena-D rockets. Lewis had taken over management of the Agena Program in October 1962.

Lewis researchers investigated two different types of shrouds for the Mariner missions—an over-the-nose design and a backup pyrotechnic design. The new shroud was wider in diameter than the Agena rocket, so there was concern that this disparity might create air flow instability that could damage the shroud or destroy the vehicle. The tests in the 8- by 6 tunnel simulated launch speeds from Mach 0.56 to 1.96. Afterwards the Agena-Mariner-C model was studied in the 10- by 10-Foot Supersonic Wind Tunnel at speeds of Mach 2.0 to 3.5.

Mariner-C was launched on November 4, 1964, but the payload shroud did not jettison properly and the spacecraft’s battery power did not function. The mission ended unsuccessfully two days later. Mariner-D was launched on November 28, 1964 and became the first successful mission to Mars. It was the first time a planet was photographed from space. Mariner-D’s 21 photographs revealed an inhospitable and barren landscape.