I believe with chemical propulsion its commonly believed to be about a
year each way. thats a long time
What if aerobreaking were used?
The manned portion would detach and dive perhaps repeatedly into the
atmosphere to slow for landing.
This would mean the transit vehicle would only accelerate on its way
to mars cutting travel time.
on a return from mars to earth could a capsule be built like apollo to
survive a full speed return?