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maxiukuk
2008-Feb-29, 01:21 PM
what year if any do you thing we can send a probe to Alpha Centauri or a close star??????

N!ck
2008-Feb-29, 01:24 PM
What year do you think the leaders of this planet will even consider it? :neutral:

I feel Earth is getting way too cozy in thinking we're alone in the universe.

GOURDHEAD
2008-Feb-29, 02:14 PM
2408, if get start the project immediately.

Noclevername
2008-Feb-29, 06:46 PM
what year if any do you thing we can send a probe to Alpha Centauri or a close star??????

Can or will? We can do it next year, if we pool all the world's nuclear weapons into building a Dyson-style Orion. But that's not gonna happen.

(And of course, that's just when we send it, it would still take millenia to get there. Most likely we'll wait until we have some faster propulsion technology, which will be in the year xxxx.)

spacestart.eu
2008-Feb-29, 07:41 PM
Which way are the voyagers heading? Do they cross a near earth star?

spacestart.eu
2008-Feb-29, 07:42 PM
And if so can the voyagers still send us data?

speedfreek
2008-Feb-29, 08:20 PM
Spacecraft escaping the solar system (http://www.heavens-above.com/solar-escape.asp?lat=0&lng=0&loc=Unspecified&alt=0&tz=CET) shows where they are right now, and how fast they are travelling.

Voyager 1 is currently 105.567 AU out, and moving at 17.108 km/s.

17.108 km/s = 0.0000571 C or 0.005% of the speed of light.

105.567 AU = 0.00167 lightyears or 0.167% of a lightyear

I don't know which direction Voyager 1 is heading, but even if it were heading for Alpha Centauri which is around 4.22 light years away, it will take that probe around 80,000 years to get there!

Noclevername
2008-Feb-29, 08:25 PM
Which way are the voyagers heading? Do they cross a near earth star?
Per Wikipedia:

Voyager 1 is not heading towards any particular star, but in 40,000 years it will be within 1.6 light years of the star AC+79 3888 in the Ophiuchus constellation.

In about 296,000 years in the future, Voyager 2 will pass by the star Sirius at a distance of 4.3 light years (25 trillion miles).


And if so can the voyagers still send us data?


Both Voyager probes are powered by three radioisotope thermoelectric generators, which have far outlasted their originally intended lifespan, and are now expected to continue to generate enough power to keep communicating with Earth until at least around the year 2020.

spacestart.eu
2008-Feb-29, 08:29 PM
@Noclevername,

thank you very much for your detailed answer.

Noclevername
2008-Feb-29, 09:23 PM
@Noclevername,

thank you very much for your detailed answer.

You're welcome.

Ilya
2008-Feb-29, 09:28 PM
In about 296,000 years in the future, Voyager 2 will pass by the star Sirius at a distance of 4.3 light years (25 trillion miles).

Considering that 4.3 ly is about half the distance from Earth to Sirius, I do not see how this can be considered "passing by" in any meaningful sense.

Noclevername
2008-Feb-29, 09:54 PM
Considering that 4.3 ly is about half the distance from Earth to Sirius, I do not see how this can be considered "passing by" in any meaningful sense.

If that's the closest it'll get to another star, I guess it counts. Sorta. Otherwise I'm stumped as to why they'd give that as an example.

tracer
2008-Feb-29, 10:33 PM
Can or will? We can do it next year, if we pool all the world's nuclear weapons into building a Dyson-style Orion. But that's not gonna happen.

I was under the impression that an Orion spacecraft (http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29) capable of fast interstellar flight could use as few as 500 small nukes. Certainly a lot of firepower, but hardly the combined nuclear stockpiles of all the world's superpowers.


(And of course, that's just when we send it, it would still take millenia to get there.

And last I heard, an Orion could have a travel time to a next-door stellar neighbor of as short as half a century.

Noclevername
2008-Feb-29, 10:53 PM
I was under the impression that an Orion spacecraft (http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29) capable of fast interstellar flight could use as few as 500 small nukes. Certainly a lot of firepower, but hardly the combined nuclear stockpiles of all the world's superpowers.



And last I heard, an Orion could have a travel time to a next-door stellar neighbor of as short as half a century.

Depends where it's launched from. In this case, I was adding in the amount to get it off Earth's surface, going for maximum speed of construction and launch.

The maximum possible speed for a nuclear-pulse thermonuclear fission rocket is estimated at 8-10% of lightspeed. Accelerating up to the maximum speed would take decades, as would decelerating at the end of the trip. And that's the best-case scenario; quite likely, as with all technologies, the first attempts will be far less effective than the simulations project, and kinks will need to be worked out to reach the highest proposed efficiency.