"Jeff Root" writes:

Craig,

I made a mistake in thinking that Max was specifying
two spacecraft, because he said "Pioneer 10-11". I now
think he only meant one, which would cut the cost a lot,
not least because of the reduction in DSN time. It might
even cut the total cost in half. Not that my estimate was
much better than order-of-magnitude to begin with.

Hi Jeff,

The example you gave put the Cassini DSN time at $44M right, so it
ends up being significant, but still not the dominant component.


On the other hand, I wonder if you noticed that Max
specified "to Neptune and *back*"?

I don't know how much cost getting back would add, but
it would have to be a lot. I assumed that getting back
means a flyby within a few million km of Earth. I'm sure
that getting back means a slower trip out, thus my
estimate of "about 20 years" for the mission.


OK, I didn't notice that, and it makes the job much, much harder. I'm
not even sure it could be done. An orbit with perihelion at earth and
aphelion at Neptune has a period of about 60 years. I'm not sure if
gravity assist could be used, and of course the re-capture near earth
would be a major task.

Craig

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Craig B. Markwardt, Ph.D. EMAIL:
Astrophysics, IDL, Finance, Derivatives | Remove "net" for better response
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