Re: Re: Re: starship-design: Re: Perihelion Maneuver

[kuo@bit.csc.lsu.edu (Isaac Kuo)]

KellySt@aol.com wrote:
>>>But Telescopes can get results quicker and certainly can get as good a
>>>optical resolution from here.

>>Actually not.  Remember that resolution is proportional to the distance
>>from the observed object.  A Voyager-like probe could fly by an
>>atmosphere-less planet a kilometer from its surface.  That gives it
>>at least a 4x10^13 advantage in resolution compared to a Solar System
>>telescope.  Assuming the Voyager-like probe had a camera with a 1cm
>>lens, the Solar System telescope would need to be at _least_
>>4,000,000,000 kilometers in diameter to equal it.

>I.E. about 10 light secounds.  Lunar orbit is 3 light secounds, earth orbit
>is about 960 light secounds.  So a 10 light secound array isn't that big of a
>deal.  Certainly far cheaper and quicker then launching a interstellar probe.


That is a big deal!  Do you have any idea how to do VLBI with
visible wavelengths?

If so, there's a Nobel Prize waiting for you.

We can do VLBI with microwave wavelengths because it's just barely
possible to measure phase with them (and thus possible to receive
multiple signals and constructively interfere them appropriately).

We _can't_ do VLBI with infrared and shorter wavelengths.  It _might_
be possible to do it in the future, but don't bank on it.

>>>Given their greater flexiblity (use in multiple
>>> star systems with the same scop) and lower cost, they'ld probably
>>>prempt any starwisp class stellar probe.

>>Yes, but starwisp doesn't have anywhere near the capabilities of
>>Voyager.  (It needs a compound eye made up of individual optical
>>"cameras" with microscopic lenses.)

>Actually its greater virtual lens size would give it a greater resolution
>(assuming you could make it work) but thats a nit.

No, starwisp used each "camera" as a single pixel camera, because
you can't do VLBI with visible wavelengths (as far as we know).

>>>>>> IMO, 10%c is sufficent for interstellar flyby missions.

>>No.  But it's possible for people to work on more than one thing at
>>a time.  Do you think the Voyager team members just sort of bummed
>>around waiting for their probes to reach Saturn?

>Pretty much.  Thats one of the reasons JPL is finding it harder and harder to
>hire good people.  They can expect to spend their careers on one project.  If
>it fails, they've done nothing.

Well, they didn't.  They actually had careers, doing other things, and
in fact only a handful of the original team stuck with it for the
entire project.

>>> Or funding sources that much more patent?  If it take a half
>>>century to get results, a inteligent person will wait a couple
>>>decades for faster cheaper systems.

>>Not if those "faster cheaper" systems aren't going to be much faster or
>>much cheaper.

>When have we not developed much better systems after a few decades?

For instance, automobiles.  Automotive technology has gotten a bit
better, but a 1960's Cobra can race competetively with anything
we can build today of similar weight/size.  A 1940's Volkswagon
is still one of the most fuel efficient vehicles you can drive.

Cars are a bit better, but not outrageously better, than several
decades ago.
-- 
    _____     Isaac Kuo kuo@bit.csc.lsu.edu http://www.csc.lsu.edu/~kuo
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