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

[KellySt@aol.com]

In a message dated 11/24/97 12:31:47 PM, kuo@bit.csc.lsu.edu wrote:

>KellySt@aol.com wrote:
>>In a message dated 11/18/97 2:03:16 AM, kuo@bit.csc.lsu.edu wrote:
>
>>>>> Maybe not, but IMO it's clearly sufficient for an interstellar probe
>>>>> flyby mission, which is all it's really good for anyway (my rule
>>>>> of thumb is that anything good enough to use for decelerating at
>>>>> an unprepared target system is good enough for the acceleration
>>>>> run.  Conversely, anything only good for the acceleration run
>>>>> doesn't really help if you want to stop at the target system.)
>
>>>>I'll buy that, but see your earlier argument _against_ the flyby mission.
>
>>>My argument against Starwisp specifically is that it's not clear
>>>it will ever be worth it, seeing as its sensor suite is so limited.
>
>>>Something with the capabilities of Voyager would easily provide much
>>>more detailed and reliable information on a nearby star system than
>>>we could expect from future telescopes.
>
>>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.


>>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.


>>>>> IMO, 10%c is sufficent for interstellar flyby missions.
>
>>>>I wouldn't want to wait that long to get my data back.
>
>>>What, 50 years?  By the time we start throwing around interstellar
>>>probes, I'll bet average human lifespans are comfortably over 100
>>>years.
>
>>Does that mean people will have careers and lives that much more sedentary?
>
>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.

In any event get funding for a 50 year project with no payback until the 50 ye
ar finish, if then, is about imposible.  


>> 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?

Kelly