They will stay there for one or two months. One more problem is radiation. Beyond magnetic fields of the Earth, which protect us against galactic space radiation and solar flares, radiation doses will be significant. But the problem could be solved. Second, a spaceship cover and facilities give effective protection.
Solar flares are more dangerous, so a special radiation shelter is needed.
Those who will land on the planet are especially exposed to solar radiation. If astronauts ever make it to Mars, they'll need a roof over their heads. Bricks are too heavy to lug all the way from Earth, but with just a few bucket-loads of polyethylene powder, they could rustle them up when they get there.