With the current technology that we have, it would be that way where you get there but it will be difficult to impossible to get back, relatively speaking. But we’ve been at work to try to not make that a reality for those visiting the planet.

This is one of the reasons why the rockets from SpaceX are so valuable in that they can land the same way they take off. Because with other rockets, we’d need a situation like we had on the moon during the Apollo years where a ship orbits the planet and waits for a separate landing ship to come back which is a waste of fuel and cuts down on the potential time that can be spent on the planet as well as resources that would be consumed and need to replenished and also waste of humans waiting in orbit instead of being part of the ground crew.

While that technology is now here, there is still much testing that still needs to be done to ensure safety is there.

What you may also be thinking of is the time in which it takes for a ship to travel between the earth and mars. At its shortest, the trip could be as little as 6 months, but is more as both planets orbit the sun further away from each other, so we are trying to find a time that works with that orbiting schedule as well so it doesn’t have to be a one way trip and they can get there and come back in a reasonable amount of time while having enough resources to last the journey.