Quote:
Originally Posted by Gardamorg
Nano Assembly would allow the spacecraft to be both strong and light.
With light fuel, and a light haul/craft, the craft will zip through space, as opposed to a craft with light fuel and a heavy craft producing drag.
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The following info should be relevant and interesting. It is from
Relativistic Rocket
Assuming that the fuel the rocket uses (matter / antimatter) is 100% efficient (The fuel is converted to massless particles and expelled at the speed of light) and also assuming that the craft has constant acceleration, then the equation for fuel to payload ratio is:
where M is the fuel, m is the payload, a is the acceleration (assumed to be 9.8 m/s/s for the table below), T is the proper time as measured on the rocket, and c is the speed of light.
To give an idea of the results, the link above has these two tables, the first is the case of going to the destination and passing it (not slowing down to stop there). The second table, which requires more fuel, is the case of accelerating at 1g for half the trip then accelerating in the opposite direction at 1g for the second half so that it is possible to stop at the destination.
D is distance, M is mass of fuel needed per each kilogram of payload:
Code:
d Not stopping, sailing past: M
4.3 ly Nearest star 10 kg
27 ly Vega 57 kg
30,000 ly Center of our galaxy 62 tonnes
2,000,000 ly Andromeda galaxy 4,100 tonnes
Code:
d Stopping at: M
4.3 ly Nearest star 38 kg
27 ly Vega 886 kg
30,000 ly Center of our galaxy 955,000 tonnes
2,000,000 ly Andromeda galaxy 4.2 thousand million tonnes
So, if you want to visit the nearest star quickly (1g acceleration) and you have a 100% efficient matter/antimatter drive and craft weighing 1,000 kg, you'll need 10,000 kg of matter/antimatter fuel. Good times.
~modest
