With current technology it's probably possible to build a 99%C speed [unmanned] spacecraft but it would cost hundreds of billions and we'd have to get over some politically difficult issues such as shipping tons of weapons-grade plutonium into NEO.
That ship would get there in 25 years or so, so most of us would live to see the reply on its telemetry around the time our grandchildren are our age.
What current technology? The energies involved in getting something to 99% of C are insanely high (the kinetic energy of each kilogram at that speed is about the same as the output of a 132Mt bomb).
Then there are the problems of traveling at that speed - which are significant.
"Realistic" designs for interstellar probes generally rely on not carrying the fuel with the probe and having ultralight masses (e.g. Bob Forwards "Starwisp" http://en.wikipedia.org/wiki/Starwisp) - this still requires impressive engineering (a 560km diameter transmitter producing 56GW) for a total probe mass of 1kg and payload of 80g. And that would "only" manage 20% of C.
In retrospect I think I exaggerated it. But if we would somehow put our effort to it and invest a couple trillion in it, it may be achievable in this century.
I don't know much about relativistic effects, but people that does told me that that's not practically possible, even with tons of money. But c/2 is not unthinkable if things like http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magne... keep developing.
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With current technology it's probably possible to build a 99%C speed [unmanned] spacecraft but it would cost hundreds of billions and we'd have to get over some politically difficult issues such as shipping tons of weapons-grade plutonium into NEO.
That ship would get there in 25 years or so, so most of us would live to see the reply on its telemetry around the time our grandchildren are our age.
What current technology? The energies involved in getting something to 99% of C are insanely high (the kinetic energy of each kilogram at that speed is about the same as the output of a 132Mt bomb).
Then there are the problems of traveling at that speed - which are significant.
"Realistic" designs for interstellar probes generally rely on not carrying the fuel with the probe and having ultralight masses (e.g. Bob Forwards "Starwisp" http://en.wikipedia.org/wiki/Starwisp) - this still requires impressive engineering (a 560km diameter transmitter producing 56GW) for a total probe mass of 1kg and payload of 80g. And that would "only" manage 20% of C.
http://en.wikipedia.org/wiki/Starwisp
Do I believe something like Starwisp will be built - absolutely. In my lifetime? No chance.
I'd be happy if we get people to Mars in my lifetime - something I don't expect to see.
In retrospect I think I exaggerated it. But if we would somehow put our effort to it and invest a couple trillion in it, it may be achievable in this century.
Yeah - it requires a city-sized power station to accelerate mere protons at the LHC to ~c.
I don't know much about relativistic effects, but people that does told me that that's not practically possible, even with tons of money. But c/2 is not unthinkable if things like http://en.wikipedia.org/wiki/Variable_Specific_Impulse_Magne... keep developing.