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"Tim Attwood" <tim### [at] comcast net> wrote:
> I'm of the opinion that a large enough power source, such as
> a nuclear reactor, could produce enough electric power to fuel a large
> ion thuster. If a thrust to power ratio of around 50 mN/kW is assumed, and
> a total ship weight of 10 tons then we're looking for a power source of
> about 2 gigawatts. This would let a ship accelerate a little over 1G for
> extended periods. Such a ship could make a round trip to Alpha Centari A in
> about 9 years. If such a vehicle was unmanned then little of the radiation
> shielding would be needed, which is what turns a reactor into a big building
> with 6ft thick cement walls.
Tim, Tim! How un-friendly sending an unshielded nuclear reactor to our
nearest neighbour :-(
What are you trying to do, start an interstellar war?
Stephen
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> Tim, Tim! How un-friendly sending an unshielded nuclear reactor to our
> nearest neighbour :-(
> What are you trying to do, start an interstellar war?
Maybe we should build one before they do...
Besides, I'm sure it's worth a couple trillion for some perty pictures,
after
all, the politicians just blow it on dumb stuff already.
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"Tim Attwood" <tim### [at] comcastnet> wrote in message
news:457fd71f$1@news.povray.org...
>> Tim, Tim! How un-friendly sending an unshielded nuclear reactor to our
>> nearest neighbour :-(
>> What are you trying to do, start an interstellar war?
>
> Maybe we should build one before they do...
>
> Besides, I'm sure it's worth a couple trillion for some perty pictures,
> after all, the politicians just blow it on dumb stuff already.
Good point, Tim....
Well Pov artists.. let's get started!
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"Tim Attwood" <tim### [at] comcastnet> wrote:
> I'm of the opinion that a large enough power source, such as
> a nuclear reactor, could produce enough electric power to fuel a large
> ion thuster. If a thrust to power ratio of around 50 mN/kW is assumed, and
> a total ship weight of 10 tons then we're looking for a power source of
> about 2 gigawatts. This would let a ship accelerate a little over 1G for
> extended periods. Such a ship could make a round trip to Alpha Centari A in
> about 9 years. If such a vehicle was unmanned then little of the radiation
> shielding would be needed, which is what turns a reactor into a big building
> with 6ft thick cement walls.
Does this estimate take relativistics effects into account? (I've long
forgotten how to do the math.) A vehicle that gets to Alpha cen in 4.5
years has to go pretty close to the speed of light. The relativistic mass
gain would surely affect the thruster's ability to maintain acceleration.
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Cousin Ricky wrote:
> gain would surely affect the thruster's ability to maintain acceleration.
It depends on whether you measure the acceleration inside or outside the
ship. The passengers can continue to experience 1G indefinitely.
--
Darren New / San Diego, CA, USA (PST)
Scruffitarianism - Where T-shirt, jeans,
and a three-day beard are "Sunday Best."
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"Cousin Ricky" <ric### [at] yahoocom> wrote in message
news:web.458015c7ff75702c85de7b680@news.povray.org...
> "Tim Attwood" <tim### [at] comcastnet> wrote:
>> I'm of the opinion that a large enough power source, such as
>> a nuclear reactor, could produce enough electric power to fuel a large
>> ion thuster. If a thrust to power ratio of around 50 mN/kW is assumed,
>> and
>> a total ship weight of 10 tons then we're looking for a power source of
>> about 2 gigawatts. This would let a ship accelerate a little over 1G for
>> extended periods. Such a ship could make a round trip to Alpha Centari A
>> in
>> about 9 years. If such a vehicle was unmanned then little of the
>> radiation
>> shielding would be needed, which is what turns a reactor into a big
>> building
>> with 6ft thick cement walls.
>
> Does this estimate take relativistics effects into account? (I've long
> forgotten how to do the math.) A vehicle that gets to Alpha cen in 4.5
> years has to go pretty close to the speed of light. The relativistic mass
> gain would surely affect the thruster's ability to maintain acceleration.
You're thinking about this way too hard! ;-)
Jon
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"Jon S. Berndt" <jsb### [at] hal-pcorg> wrote:
> "Cousin Ricky" <ric### [at] yahoocom> wrote in message
> news:web.458015c7ff75702c85de7b680@news.povray.org...
> >
> > Does this estimate take relativistics effects into account? (I've long
> > forgotten how to do the math.) A vehicle that gets to Alpha cen in 4.5
> > years has to go pretty close to the speed of light. The relativistic mass
> > gain would surely affect the thruster's ability to maintain acceleration.
>
> You're thinking about this way too hard! ;-)
Well, he *did* say "realistic." It's details like this that cause
expensive, taxpayer-funded space probes to vanish without a trace.
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"Cousin Ricky" <ric### [at] yahoocom> wrote:
> "Jon S. Berndt" <jsb### [at] hal-pcorg> wrote:
> > "Cousin Ricky" <ric### [at] yahoocom> wrote in message
> > news:web.458015c7ff75702c85de7b680@news.povray.org...
> > >
> > > Does this estimate take relativistics effects into account? (I've long
> > > forgotten how to do the math.) A vehicle that gets to Alpha cen in 4.5
> > > years has to go pretty close to the speed of light. The relativistic mass
> > > gain would surely affect the thruster's ability to maintain acceleration.
> >
> > You're thinking about this way too hard! ;-)
>
> Well, he *did* say "realistic." It's details like this that cause
> expensive, taxpayer-funded space probes to vanish without a trace.
taxpayer-funded space probes to vanish without a trace.
Ok there was a trace :-)
Stephen
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"Stephen" <mcavoys_AT_aolDOT.com> schreef in bericht
news:web.45810d28ff75702cf1cb1e660@news.povray.org...
Ok there was a trace :-)
>
trace( ) ?? :-)
Thomas
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"Thomas de Groot" <t.d### [at] internlDOTnet> wrote:
> "Stephen" <mcavoys_AT_aolDOT.com> schreef in bericht
> news:web.45810d28ff75702cf1cb1e660@news.povray.org...
> Ok there was a trace :-)
> >
> trace( ) ?? :-)
>
> Thomas
"Hanging is too good for a man who makes puns; he should be drawn and
"Puns are the last refuge of the witless."
"Immanuel doesn't pun; he Kant."
Stephen
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