RadialGal and others nailed it, trust and independence from both sides is huge. Been in the 121 biz now for over 12 years and still happily married the whole time. We are both fine with time apart and then enjoy our time together even more as a result. No reports/emails, phone calls, etc. keeping either of us distracted from the other when both of us are home (her job has very little outside of work responsibility).

So it most certainly can be done with the right partner, just gotta find the right one and learn to make the best of an odd career.