alternatehistory.com

Take proposed but unsuccessful space missions, whether because of rocket/spacecraft failure, lack of political will, lack of funding, or some other cause aside from physical/engineering plausibility (no Orion please, already been hashed out hundreds of times), and...WI they succeeded?

Alright, a couple from me:
Voyager: goes forward to 'bridge the gap' between Saturn and Shuttle, using one of the Saturn Vs scheduled for a late Moon mission. This is a bit of mixed bag. The projected spacecraft was not quite as capable as Viking in all aspects, but I think it's likely it will be improved, as there's only one chance at this. The larger loft weight may allow a much bigger, more capable spacecraft to be landed (and orbited), which would allow for much better science.

TOPS: The only reference I can find is an old NRC study, but basically super-Voyagers (the OTL ones). Large, RTG powered craft with a long design lifetime, substantial scientific payload, and a structure designed to be used in a Galileo-type role as well. The projected idea was to use them in the Voyager 2 Grand Tour role with (IIRC) 2 bound for Jupiter-Saturn-Neptune, 2 bound for Jupiter-Saturn-Uranus, and 2 bound for Jupiter-Saturn-Pluto. The latter especially would be nifty, as Pluto was then relatively close to the Sun and hence a probe going there could have studied the Plutonian atmosphere, and generally low-temperature atmospheric dynamics. My favorite never-flown mission, TBH. Damn budget cuts :mad:

EDIT: Ah ha, Wikipedia come through! Here is an outline of the proposed mission. 2 probes Jupiter-Saturn-Pluto, 2 Jupiter-Uranus-Neptune. Not quite as ambitious as I thought, but still my favorite canceled program.

Planetary Observers: Capable, relatively cheap inner-system exploration satellites. Between the failure of Mars Observer, the Goldin "Cheaper, faster, better" motto, and the stillbirth of SEI, they never had a chance OTL. The loss of Mar Observer (just a few days from the orbit insertion burn) was particularly devastating, setting back Mars science for literally a decade as many instruments flown on it were re-flown on the highly successful late-90s missions. Continuing on with it, a capable Moon orbiter would have been flown a few years later, possibly giving results only now beginning to come back from the armada that's visited recently, a Mercury orbiter would have been flown over a decade earlier than OTL (and that mission's success is not certain yet), and possibly other missions. A very sad thing :(

Mariner Mark II: Not really a single spacecraft, Mariner Mark II was supposed to be an overarching designator for a new class of outer-system craft. Cassini (currently in orbit around Saturn) and CRAF (Comet Rendezvous Asteroid Flyby) would have been the first two missions. Like the Planetary Observers, killed by budget cuts, though Cassini survived. May have helped the cause of outer-system exploration by somewhat reducing costs in the design and production stage. More pertinently, CRAF might very well have provided many useful results which OTL were acquired years later about cometary and asteroidal behavior.

Pioneer H: This one would have been cool and cheap. Using Pioneer 10-11 spares, engineers had built a fully functional additional probe. They proposed using it to launch a mission which would probe the out-of-ecliptic solar system environment, something which was OTL done to some extent about a decade later with Ulysses. This one would probably have been looking more at the interplanetary environment in those areas and the solar magnetic field than the sun itself though. At least the Smithsonian got a nice display out of it.

So what are your favorites?
Top