Hi All

It looks good - the interactive web-site is fun. But the choices of location and technology really let it down IMHO. An imaginary binary seems odd since there are so many real and interesting locations, but perhaps the choice of propulsion let them down - antimatter-triggered fusion. For a delta-vee of 0.4 c that means an exhaust velocity of ~ 0.25 c to minimise antimatter needed - and at that sort of energy level most of the kick is coming from antimatter. Fusion gets maybe ~ 0.6% energy conversion, yet the exhaust needs ~ 3% to hit 0.25 c - thus 80% is from the m-am reactions. Total antimatter needed is about ~6% of the ship/payload mass, so at least several tons.

Since the probe took 42.5 years to reach 6.5 ly with a cruise of ~ 0.2 c it means the boost phase was ~ 20 years long, so acceleration was ~ 0.02 g.

Personally I would've gone with beamed energy propulsion - a "nano-hockey puck" pellet stream could easily boost the probe to ~ 0.4 c and rapidly. Then a magnetic-sail or plasma-sail could deccelerate the probe for rendevous. Any star within ~ 16 light years would be feasible in 42.5 years transit time.

Adam