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Old 17-01-2013, 10:11 AM
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mithrandir (Andrew)
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Join Date: Jan 2009
Location: Glenhaven
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Quote:
Originally Posted by snas View Post
"For my model I have chosen a spacecraft with a crew of six that will leave its planet for a planet in the habitable zone of a star 10 light years away. It will be accelerated at a rate of 10 m/s2 (10 meters per second squared) to a velocity of 0.5 times the velocity of light (0.5c, where c is the velocity of light). The time for it to reach this velocity is given by this equation:
t = v/a = 1.5×108/10 = 3.06×107 s = 174 days
(a = acceleration in meters/second squared; v = velocity in meters/second; s = time seconds)"
From an external frame of reference, to get from 0 to 0.5c (~150000km/sec) with acceleration 10m/sec
150000000/10/86400 ~= 174 earth days

Did they explain their magic numbers, or take into consideration the relativistic effects, or the mass of propellant required?

Neglecting practical issues and relativity, by that time they will have covered 1.125e12 km or about 0.2 LY.
The next 9.6 LY will take 19.2 years.
Decelerating at the same 10m/sec will then take another 174 days and cover another 0.2 LY
So the total is 19.2 + 2*174/365 or about 20.15 years
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