“With this revolutionary technology, a variation of which has since been used by the Dawn spacecraft to reach Vesta, the SMART-1 mission took one year, one month and two weeks to reach the Moon. “
What? Huh? Maybe I’m missing something.
They probably took the scenic route.
Ion drives are highly efficient, in terms of the thrust you get for the weight of propellant you carry, but they are also extremely low powered. That’s why it took so long.
It accelerates at a very low rate but steady—gradually increasing orbits are the result. But it uses relatively very little fuel to do so. That’s the big deal. Steady but low acceleration for a long time results in very high velocity. And you don’t have to accelerate all that fuel.
Seems like a hot air balloon (if it were possible) could get to the moon quicker than a year...