The Grand Tour, A proposal that ended with Voyager 1 & 2 Options

[Guest_Myran_*]

Seeing descriptions and even images of old projects that never did get underway, my memory was stimulated into remember 'The grand tour' plans.

Back in the 1960 the proposal was to fly no less than 4 spacecrafts, each with atmospheric probes for the four gas giants and one even with a flyby of Pluto after swinging past Jupiter and Uranus.

The proposal for this project did fare the same way as many other ambitious plans, that of limited funding but it was skillfuly advocated and eventually ended up with the dual Voyagers (which btw originally only was planned for flyby's of Jupiter and Saturn).

Regardless, if anyone remember some tidbits or even sits on more specific information I would be happy to have my memory refreshed. Thank you in advance!

[Guest_BruceMoomaw_*]

The article I was after is D. Rubashkin's "Who Killed the Grand Tour? A Case Study in the Politics of Funding Expensive Space Science", in JBIS, Vol. 50, pg. 177 (year 1997). Unfortunately, it isn't available on the Web.

The short version is that Grand Tour was like Rodney Dangerfield -- at the time, it got shockingly little respect from ANYBODY. The Space Studies Board (aka COMPLEX) took a surprisingly dim view of it (as compared to the intensive exploration of Jupiter alone), and in fact recommended it be flown only if NASA's space science budget got a 50% hike for the rest of the decade -- which everyone knew wouldn't happen. Sen. Clinton Anderson of NM (then chairman of the Senate Aeronautical and Space Sciences Committee) took a very dim view of it because it was bleeding off funds from the NERVA nuclear rocket program, which he fiercely defended because Los Alamos was associated with it; no other member of Congresss seems to have any fondness for it; and Pres. Nixon had no intention of funding anything that would interfere with the Space Shuttle's development.

Anderson used the idea that NERVA and other nuclear rockets might allow space probes to be launched DIRECTLY to the three outer planets to bash Grand Tour mercilessly in 1971. By mid-1971 GT was already virtually moribund (and NASA had already dropped its plans to launch a preliminary test of the craft in 1975 that would fly by Jupiter and then go sharply out of the ecliptic, and had also delayed the launch of the first of the two Jupiter-Saturn-Pluto craft, which was originally supposed to fly in 1976 instead of 1977).

The last straw came in October 1971, when Nixon decided that in order to properly fund Shuttle he had to cancel either Apollo 16 and 17 (which he initially leaned toward doing), or GT (which NASA and COMPLEX persuaded him to do instead). At the same time, ironically, the White House zapped NERVA, briefly mollifying Sen. Anderson (who retired only a year later) with a smaller nuclear propulsion program which they also cancelled as soon as he was safely gone. The moment GT was cancelled in Dec. 1971, however, NASA and the White House replaced it with Mariner Jupiter/Saturn, which by contrast everyone -- COMPLEX, the White House and Congress -- immediately and enthusiastically endorsed, largely because it would cost less than half as much. (NASA still hoped from the start to fly at least one such craft to Uranus and Neptune, but without the "Self-Test And Repair" computer that was a major feature of the GT craft.)

The article doesn't say anything about the sequel to this story: NASA's brief hopes of flying Mariner Jupiter/Uranus in 1979. I'll do a bit more digging on that subject, but the main story is very simple: as with so much else, the Shuttle ate it. (And I have still seen no sign that GT was intended to carry any entry probes -- indeed, I very clearly remember that the detailed description of the GT craft in "Astronautics and Aeronautics" magazine at the same time included no mention of any entry probes.)