How Long Does it Take to Fly to the Moon?

Answer? Not as long as I thought. It can take as long as a year, if you use an ion engine, which is very fuel efficient. Or, you can get there in a mere 8 hours, but only if you're using rockets propelling you at 52,000 mph. The Apollo team did it in a few days; they were in lunar orbit after 3 days. I had it in my mind it took them weeks, so I learned something useful today.

I'm not finding as simple a presentation of different times and velocities for going to Mars, but here it is said that a manned trip would be, round-trip, around two years, which includes several months stay on Mars. Keeping in mind that the current longterm duration in space is around half that time, and that Russian cosmonauts (who set that record) experienced serious medical problems, it sounds like we're not even close to knowing whether humans can survive the trip, even if technically they can get there in an otherwise safe and efficient vehicle.