Return To The Moon, Everything Old is New again Options

[nprev]

Phil, I must respectfully disagree with part of your thesis. I think that we do indeed need to know how to develop methods to stay indefinitely on a planet's surface, esp. one as austere as that of the Moon in terms of indigenous resources. This research will, hopefully, yield if nothing else vastly improved life support technologies which can in turn be applied to Mars and beyond.

[dvandorn]

Besides, I didn't specifically mention Mars, did I? I'm firmly convinced that humans will and ought to visit small solar system bodies (asteroids and possibly comets), perhaps even before we set foot on Mars.

Mars presents its own unique resources, opportunities and challenges. It's relatively hard to land on Mars, for example, because of its combination of gravity (high enough to draw a lander down with fatal velocity) and thin atmosphere (which doesn't provide all the braking you'd like). And we have yet to have a complete chemical analysis of Martian soils -- if they are rich in peroxides, we could be dealing with severe environmental issues when trying to live there.

But the Moon provides many similar environmental factors to what we will find on asteroids. Operating in vacuum, dealing with variable amounts of insolation, working in potentially severe radiation environments... these are all factors that are similar on the Moon and on asteroids.

In some ways, working on the Moon will be easier than working on small bodies, because you have a certain amount of gravity to hold things in place. But it's easier to land on small bodies -- though it might be a little *too* easy to lift back off of them.

So, when I spoke of the importance of learning how to live for extended periods on planetary surfaces, I was mostly speaking of minor planets. Like Ceres and Vesta. Or even Eros.

-the other Doug

[gndonald]

The choice of landing site for Apollo 14, assuming a successful Apollo 13 mission, was dependent on the time of year 14 was to be launched. Littrow was only available in fall and winter months, Censorinus was only available in spring and summer months.

When Apollo 13 was scheduled for November, 1969 (continuing the every-two-month flight pace, and assuming an Apollo 12 mission flown in September), Apollo 14 was scheduled for a January, 1970 flight. (If Apollos 11, 12 and 13 had failed to land, Apollo 14 could have been pushed up to December, to try and beat the end-of-decade deadline.)

By the time a landing site was being considered for Apollo 14, however, the flights had been paced out to once every four months -- and, even before Apollo 13 flew, that was stretched again to five-six months. Had Apollo 13 flown in March, 1970 and Apollo 14 in July (the situation when landing sites were first being discussed), 14 would have landed at Censorinus. However, when 13 was pushed back to April, 14 got pushed back to October. At that point, Littrow was available, so as of mid-January, 1970, Shepard and Mitchell began to train for a landing at Littrow.

Now, to be clear, the H-3 Littrow site was *not* the Taurus-Littrow site visited by Apollo 17. The H-3 Littrow site was about 30-40 km to the west of the Taurus-Littrow valley, out in the Sea of Serenity. It was at the boundary of the dark-mantled mare surface, at a place where a wrinkle ridge is coincident with the albedo boundary. Had the H-3 site been visited, the ancient nature of the dark mantling would have been clear, and Taurus-Littrow would likely not have been a later landing site.

If Apollo 14 had flown in October, 1970 and landed at Littrow, H-4 (assuming we flew out through Apollo 18 or 19) would have been flown to Censorinus in April or May, 1971.

After that, well -- Apollo 16 was always targeted for Descartes, and would likely have remained so. In this scenario, it would have been the first J mission.

Hard to say where Apollos 17 and 18 would have ended up. If the program had ended with Apollo 17, then Schmitt would probably have been skipped ahead onto Cernan's crew, as really happened, and the mission would likely have gone (IMHO) to Hadley-Appenine. If Apollo 18 was flown, though, I bet they would have saved Hadley for it -- a fitting end to Apollo's explorations. Perhaps Cernan and Engle would have gone to Alphonsus, and then Gordon and Schmitt would have finished out the program at Hadley. (Alphonsus was always the first or second runner up at each of the J mission site selections, with the Marius Hills finishing about the same. So, the additional site could have been one of these, or perhaps somewhere else... it's truly hard to say.)

This is a very late reply to this one and Phil's book probably has all of this, but I've just found a pre-Apollo 13 target list that seems to have been compiled just before that mission launched.

It covers Apollo 13 to Apollo 19.

Here are the targets, format is [Prime Target/Backup Target].

Apollo 13 (H-2): Fra Muro/Flamsteed P

Apollo 14 (H-3): Littrow (not Apollo 17 site)

Apollo 15 (H-4): Censorinus/Davy Crater Chain

Apollo 16 (J-1): Marius Hills

Apollo 17 (J-2): Descartes/Tycho (Surveyor 7 landing site)

Apollo 18 (J-3): Copernicus Peaks

Apollo 19 (J-4): Hadley-Appenines

The list itself is contained in a 3mb discussion of science objectives dated March 11, 1970.