User:Honeyant/sandbox

1966 to 1968
In the 1966 to 1968 period the NASA lunar program of Surveyor, Lunar Orbiter and Apollo backup support almost fully utilised the DSN. The Pioneer, Surveyor and Lunar Orbiter programs all supplied mission dependent equipment at the tracking stations for command and telemetry processing purposes and this could be quite large. For example, the Lunar Orbiter equipment at DSS 41 required an extension to the control room, a photographic processing area and darkroom, and water de-mineralising equipment. Station personnel maintained and operated the Pioneer equipment, but the considerably more involved Surveyor and Lunar Orbiter equipment was operated by mission personnel, at least on the early missions.

One network of three stations was equipped for Surveyor, and another network dedicated to Lunar Orbiter. Support was also needed for the Mariner 5 Venus mission, and for Pioneer 6-9 interplanetary spacecraft which kept operating long after their expected lifetimes. Mariner 4 was also picked up again. DSS 14, the new 64m antenna, was called on to support nearly all of these missions but not always as a prime site.

To simplify the problems of accommodating special command and telemetry equipment and personnel at stations, the DSN developed a "multi-mission" approach. A generic set of equipment would be provided that future missions would all use, and a start was made by introducing computers at the stations to decode telemetry. Mission dependant equipment could be replaced by separate computer programs for each mission. Another significant improvement at this time was the introduction of ranging systems that used a coded signal transmitted to and returned from the spacecraft. The time of travel was used to measure the range more accurately and to greater distances, and this improved trajectory determination and navigation.