Proxima Centauri nearest star.
Distance 40,208,000,000,00km = 0.425 light years.
Rocket which uses 200 nukes to propel itself ( i believe this was based on an old research paper from ages ago - anyone know which one I am referring to?) 
Design ( Simple rocket + shield + nuke layout )
Speed is around 95% speed of light = roughly 1 light year.Interesting note: Time dilation from earth for observers = 365 * 2 = 730 years.Now I realise there is a big mistake somewhere, but I cant remember what it is, if someone smarter could tell me that will be great thank you.  Please excuse the rudimentary math - thank you.