Pioneer 11 to Uranus?

[R36Coach]

I noticed this on the NASA Solar System Simulator program the other day, that in 1985 when Pioneer 11 crossed the orbit of Uranus, it came quite close. Were they any plans for Pioneer 11 to directly aim at Uranus in 1985 after Saturn in 1979? The trajectory was possible and could have been done.

 

[thnkrx]

Part of the old 'grand tour' of the solar system - two? probes making flyby's of all the major outer planets.

I seem to remember it did snap a few pics and take some readings on the way through. I believe one of those old time probes discovered the rings of Uranus.

 

[R36Coach]

Voyager 2 visited Uranus in January 1986. The "Grand Tour" later evolved into the Voyager program. What I was curious was that if Pioneer 11 ever was considered for Uranus. Voyager 2 passed Saturn in mid 1981 however Voyager 1, since it was aimed to give a close encounter with Titan could not travel to any further planets.

 

[3488]

Welcome to SDC R36Coach,

Yes, it was considered for Pioneer 11 to encounter Uranus & possibly even Neptune too.

However it was decided that Pioneer 11 would not be capable of returning anything of real use from Uranus, so it was decided to scrap that plan altogether & focus on the first ever encounter of Saturn instead, rather than carry out a half baked Saturn encounter so Uranus could be encountered.

R36Coach is correct about Voyager 1. In order for Voyager 1 to encounter Titan, Voyager 1 had to pass over the high southern latitudes of Saturn, then deflect north, close pass Titan (this was deliberate as Voyager 1 could image a large latitudal swathe on Titan, almost from pole to pole, but instead was confronted by that orange hydrocarbon smog) then out of the plane of the solar system, so no Uranus or Neptune encounters were possible.

Hi thnkrx,

The rings of Uranus were discovered from the Kuiper Airbourne Observatory, when Uranus occulted a star. The occultation was viewed from high altitude on board a modified C141 aircraft. The high altitude allowed for better spectra to be obtained of the atmosphere of Uranus & more accurate visual observations were obtained to pin down the actual size of Uranus .

What happened was that the star winked out I think seven times very briefly, both before & after the occultation, symetrically, revealing the rings. Follow up observations eventually imaged the rings & Voyager 2 is the only spacecraft to have imaged them in detail to date & discovered many more. Hubble Space Telescope has also seen them very well since.

Andrew Brown.