Voyager-1 at 100 AU!, A space milestone this month Options

[dilo]

Nobody highlighted this and I didn't find any comment from Nasa/Voyager sites.
On August,11 the intrepid Voyager-1 probe will reach 14.960 billion Km from the Sun, one hundred times the average Earth-Sun distance!
This event will be followed, after 16 days, by the 100AU from Earth reach.
From astrophysical standpoint, first event is the most important but, I think, most people will be emotionally hit from the second one.
So I would like to start a poll on this.

[Guest_Analyst_*]

Voyager, the grand tour, started as the Thermoelectric Outer Planet Spacecraft (TOPS) in the late 1960ies Because of the long travel time a new computer, the so called Self Test And Repair (STAR) general purpose machine was planned to be used. Different launch strategies were discussed. One was two launches in 1977 to Jupiter-Saturn-Pluto and two in 1979 to Jupiter-Uranus-Neptune. The ideal planetary alingment in the late 1970ies has been identified at Caltech/JPL. The spacecraft were not that much larger (although they required a Titan 3E with 7 segment SRMs for some trajectories), but more sophisticated, designed to suvive 10+ years, and thus more expensive. In the early 1970ies, during the end of Apollo and the birth of the Space Shuttle, the Nixon administration canceled TOPS, the grand tour, for budget reasons (They had a useless war to fight, very much like today.).

Shortly thereafter NASA came up with Mariner Jupiter-Saturn (MJS), a design based on the Mariner spacecraft, being less expensive and more simple. MJS used a lot of the Viking computer and you can see the Mariner heritage if you look at the 10-sided bus. During development MJS involved into an almost new design: 3.7m high gain antenna, X-band primary, radiation hardened parts, RTGs, hydrazine trusters etc. But MJS was planned only explore Jupiter and Saturn within a four year mission. Before launch it was renamed Voyager (The program to develop unmanned Mars landers to be launched on Saturn launch vehicles has also been called Voyager in the 1960ies and later became Viking.). During launch were was the option to send the first launched spacecraft (JSX) to Uranus (X=U), if the other (JST) performed well during its mission including the very important close Titan encounter. We all know it did and Voyager 2 went to Uranus and Neptune. And both are still working.

It is a great story, even long before launch. A good reference is: Dethloff/Schorn: To The Outer Planets And Beyond - Voyager’s Grand Tour

Analyst