If NASA could communicate with Mark right now, they'd tell him that communication isn't as important as survival. Luckily for everyone involved, however, Mark isn't that crazy—yet. Although he's not ready to throw caution to the wind and travel to the Ares 4 site, he really needs someone to talk to.

For many, prolonged isolation can be a one-way ticket to crazy-town. Mark never goes bonkers (luckily, they didn't bring any volleyballs along for the trip), but the possibility is a very real one.

Okay, so this one rates pretty low as far as sacrifices go, but we think it bears mentioning. Why? In our eyes, it gives a glimpse of the little ways that people have made sacrifices for the sake of Mr. Watney. Venkat is already running on fumes and he still has miles to go before the finish line. This is going to be a bumpy ride.