**4015 Spaceship without people**

The 4015 spaceship is needed to take plants and animals to a destination ten light years away and assumes we need seeds or eggs and sperm from all living things. However in 2,000 years we will probably be able to reproduce life using the DNA data of the life form stored on a computer.

Hence all we need to send is computer data plus robots

All we then need to send to Maxwell is a spaceship carrying a set of robots and a way to deliver them to the surface of Maxwell without help from the Earth as a transmission each way takes 10 years. The robots would use the data on the computers to populate a new Earth with old Earth's plants and animals.

So my spaceship may be completely unnecessary.

Hence no human cargo. No plant cargo. No need for anything but a very fast spaceship

Hence the spaceship would not need rotation, air supply, crops.

Our spaceship is now going to be very much smaller and lighter.

It will be just a storeroom driven by a BIG motor.

If we assume that the spaceship will have a mass of two Saturn 5 rockets so it will be 1/100 of our 4015 spaceship, that is 6 x 10^{6} kg.

If we assume the thrust is still 180,000 N

F = ma

a = F/m = 180,000N/ 6 x 10^{6} kg

= 3 x 10^{-2} m/s/s

The time it will take for our computer and robot carrying spacecraft to get to Maxwell assuming an acceleration of 3 x 10^{-2} m/s/s for half the distance and then double this time as deceleration at the same rate will take place. Remember that the distance to Maxwell is 10 light years so s = 5 light years.

s = ut + ½ at^{2}

Starting from rest so u = 0

s = ½ at^{2}

s = 5 x 3 x 10^{8} x 3600 x 24 x 365 m

t^{2} = 2s/a = 2 x 5 x 3 x 10^{8} x 3600 x 24 x 365/3 x 10^{-2}

t^{2} = 2s/a = 2 x 5 x 10^{12} x 36 x 24 x 365

t^{2} = 3153600 x 10^{12}

t = 1776 x 10^{6} s

t = 56 years of acceleration followed by 56 years of deceleration.

Total time 112 years for the spaceship to reach Maxwell from Earth with one motor.

The DNA message is on the computer but what organic material is there to give the message to?

So in a bit over a hundred years we have got the DNA message of all Earth's life forms to Maxwell on a computer with robots to implant the DNA message into organic matter. So we need to have sent along some fast growing algae spores to give a base for the new life or if we find life already on Maxwell we can convert it to Earth life.

This means that if there is a life form more advanced than ours a relatively close 10 light years away from Earth then we would not be seeing little green men coming out of a spaceship but R2D2s whose job it is to repopulate the planet.