— Ch. 1 · August Launch And Eleven Month Cruise —
Viking 1.
~4 min read · Ch. 1 of 6
The Titan/Centaur rocket lifted off from Earth on the 20th of August 1975. This launch vehicle carried the Viking 1 spacecraft toward its distant target. An eleven-month cruise followed this initial departure into space. The journey covered vast distances before the craft reached Mars orbit. Engineers monitored the trajectory closely during this long transit period. No human crew rode aboard this robotic vessel. The silence of deep space surrounded the machine for months. Scientists watched telemetry data stream back to mission control in California. The spacecraft traveled through the solar system without stopping or slowing down significantly. It arrived at Mars after nearly a full year of travel. The orbiter began returning global images about five days before entering orbit. These early pictures showed the red planet in detail for the first time. Mission planners prepared for the critical insertion maneuver that would follow.
Orbiter Imaging And Solar Delays
Viking 1 Orbiter entered Mars orbit on the 19th of June 1976. The spacecraft trimmed its path to a specific certification orbit by the 21st of June. Primary instruments included two vidicon cameras and infrared spectrometers. These tools mapped water vapor and thermal patterns across the Martian surface. Operations paused when solar conjunction began on the 5th of November 1976. Sun interference blocked radio signals between Earth and Mars during this period. The extended mission resumed on the 14th of December 1976 after the sun moved out of the way. Close approaches to Phobos occurred in February 1977. Engineers reduced the periapsis altitude to 300 kilometers on the 11th of March 1977. Minor adjustments continued throughout the mission life. Orbit height rose to 357 kilometers on the 20th of July 1979. Attitude control gas ran low by August 1980. The orbit shifted from 357 by 33,943 kilometers to 320 by 56,000 kilometers. This change prevented impact with Mars until at least 2019. Operations officially terminated on the 17th of August 1980 after 1,485 orbits. More than 57,000 images traveled back to Earth over the years.