Mariner 3

Background

Mariner 3 used a new, larger bus with four solar panels, a TV camera, and additional instrumentation, unlike Mariner 2 which had been a modified Ranger lunar probe. The greater mass required the Agena D stage instead of the Agena B, and a new, larger fiberglass payload fairing was employed. Atlas vehicle 289D was erected on LC-13 on August 17, 1964, with the backup on LC-12 erected September 28.

Launch failure

Launched at 2:22 PM EST on November 5, 1964, from Cape Kennedy Air Force Station Launch Complex 13, the Agena completed its burn to place the probe on a Mars trajectory. Telemetry an hour later showed instruments functioning but no solar panel operation. Ground controllers turned off rate gyros to conserve power while diagnosing the problem.

Telemetry suggested a separation failure of either the Agena or the payload fairing, and below-normal velocity indicated the fairing had not separated. A command to manually jettison the shroud failed, and firing the midcourse correction engine to blow it off was considered but not executed in time. Eight hours after launch, the batteries died and the mission was terminated; even if the shroud had been removed, the low velocity would have caused Mariner 3 to miss Mars by several million miles.