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"Stephen" <mcavoys_AT_aolDOT.com> wrote:
> "Pun (n.): the lowest form of humour" —Samuel Johnson, lexicographer
> "Hanging is too good for a man who makes puns; he should be drawn and
> quoted." —Fred Allen
> "The pun is mightier than the sword." — James Joyce
> "Puns are the last refuge of the witless."
> "Immanuel doesn't pun; he Kant."
punish (v) to tell a pun.
punishment (n) the telling of a pun.
--unknown
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"Bill Pragnell" <bil### [at] hotmail com> wrote in message
news:web.458138e3ff75702c731f01d10@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.
>
> I think 9 years is more likely to be the one-way trip, assuming you
> accelerate at 1g to halfway and then turn round and decelerate ass-first
> the rest of the way. A round trip would be more like 16-18 years. The crew
> would only see it as 7-8 years, of course.
I omitted relativity, the 9 years would be shipboard time, including
some fudge factor for midpoint turn around time and time for the
actual mission...
We don't really know what would happen at those speeds, we
only know that we have observed relativity at the slow end of
the curve IRL.
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Download 'space_thruster.jpg' (33 KB)
Preview of image 'space_thruster.jpg'
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"Cousin Ricky" <ric### [at] yahoocom> wrote in message
> Or typing a period in a computer program where there should have been a
> comma. Er... OK, so it *could* have happened if NASA hadn't caught the
> bug
> in time. Unfortunately, they didn't catch the missing hyphen in Mariner
> 1's
> backup guidance software...
>
> And the most grievous error of all: Sending your space ship to Mars!
> After
> Spirit and Opportunity successfully docked with the Angry Red Planet, NASA
> convened a study to find out what went *right*. :-O
Actually, it's good to keep in mind that NASA has landed 5 spacecraft
successfully on Mars out of 6 attempts (the accidental attempt to land an
*orbiter* doesn't count! ;-) - I'm referring to MCO; I'm also not counting
penetrators).
Mars has "eaten" a lot of spacecraft. The former USSR tried several times
and was unsuccessful. Beagle was a high-risk attempt that failed. It's too
bad these probes were not heard from again, because I'm sure they would have
produced fascinating results. To provide some balance, the former USSR was
successful twice at returning images from the surface of Venus - an
admirable accomplishment when you consider the conditions on the surface of
that hellish place.
Recently, the images returned by the Soviet Venera craft have been
reprocessed using modern techniques. The newly revitalized images are very
nice and worth a long look:
http://tinyurl.com/yn7dtf
Space exploration, planets, etc. are all a great field to take inspiration
for POV art!
Jon
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"Tim Attwood" <tim### [at] comcastnet> wrote
Hey, I kind of like this (I think I've seen something like this in my
kitchen, too!)
A couple of notes:
1) There should be no over-expansion of the nozzle, I think. All of the flow
would be almost all directed aft.
2) I'm sure this is a WIP, but thought I'd mention that there would be more
to the engine (a lot of equipment creating magnetic fields - coils and
stuff, supply lines for fuel, etc.)
3) The structural elements would include more bracing, similar to the
trusses you see on the space station. Maybe some antennas, too (a large-ish
dish?)
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Jon S. Berndt nous apporta ses lumieres en ce 14-12-2006 22:07:
> "Tim Attwood" <tim### [at] comcastnet> wrote
> Hey, I kind of like this (I think I've seen something like this in my
> kitchen, too!)
> A couple of notes:
> 1) There should be no over-expansion of the nozzle, I think. All of the flow
> would be almost all directed aft.
The over-expansion is unavoidable. All you can do, is try to minimise it.
> 2) I'm sure this is a WIP, but thought I'd mention that there would be more
> to the engine (a lot of equipment creating magnetic fields - coils and
> stuff, supply lines for fuel, etc.)
Depending on the scale, that can be all contained within the nozle.
> 3) The structural elements would include more bracing, similar to the
> trusses you see on the space station. Maybe some antennas, too (a large-ish
> dish?)
--
Alain
-------------------------------------------------
Do not bite at the bait of pleasure, till you know there is no hook beneath
it.
Thomas Jefferson
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"EagleSun" <nomail@nomail> wrote in message news:457f2619
> Hi Jon!
>
> It's really exciting to see someone from Houston on this forum AND
> publishing magazines. Looks like Tek has a very good ship for you....
> would you need background to go with it? I've been rendering planets,
> including a few to show in a movie...
>
> Let me know if you need something...
If a ship does come out of this, a planet might be a nice background. Not
sure if the image would portray braking into orbit or leaving ... hmmm.
Jon
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"Alain" <ele### [at] netscapenet> wrote in message
news:45828032@news.povray.org...
> Jon S. Berndt nous apporta ses lumieres en ce 14-12-2006 22:07:
>> "Tim Attwood" <tim### [at] comcastnet> wrote
>
>> Hey, I kind of like this (I think I've seen something like this in my
>> kitchen, too!)
>
>> A couple of notes:
>
>> 1) There should be no over-expansion of the nozzle, I think. All of the
>> flow would be almost all directed aft.
> The over-expansion is unavoidable. All you can do, is try to minimise it.
>> 2) I'm sure this is a WIP, but thought I'd mention that there would be
>> more to the engine (a lot of equipment creating magnetic fields - coils
>> and stuff, supply lines for fuel, etc.)
> Depending on the scale, that can be all contained within the nozle.
Visually, what I would like to see is probably best illustrated by looking
at a Hall thruster:
http://fluid.ippt.gov.pl/sbarral/hall.html
(see Pratt and Whitney thruster at bottom of this page)
http://www.engin.umich.edu/dept/aero/spacelab/thrusters/thrusters.html
http://www.adastrarocket.com/Plasma.html
There is little, if any, overexpansion of exhaust in these images. The image
by Tek was very good in this respect.
Jon
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Here's what I've come up with so far. Needs a lot of texturing and all
still. The basic idea is a cargo hold up front, fuel tanks and solar
panels surrounding a central living area, and some engines in the back.
The cargo acts as impact shielding, the hydrogen acts as
radiation shielding, and the engines make it go. A lot of it is
parameratized, so it's tweakable. Here's one configuration
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And another
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"o.bb.spammed" <o.b### [at] gmailcom> wrote:
> Here's what I've come up with so far. Needs a lot of texturing and all
> still. The basic idea is a cargo hold up front, fuel tanks and solar
> panels surrounding a central living area, and some engines in the back.
> The cargo acts as impact shielding, the hydrogen acts as
> radiation shielding, and the engines make it go. A lot of it is
> parameratized, so it's tweakable. Here's one configuration
Errr. Oops
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Attachments:
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Preview of image 'ship_back_1.jpg'
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