Defying Gravity isn't a bad show, but it's not a great show either. I thought the two episodes ABC aired back-to-back on Sunday were actually decent. Some of the Grey's-esque sex scenes may cause some eye-rolls and some of the space graphics are cheesy, but the most appealing part of the show (in my opinion) are the Lost-esque flashback sequences. I like how they flashback to show the characters in situations before their space mission. It's slightly clichéd with the Grey's-esque narration and the Lost-esque flashbacks, but it's not a bad choice for summer viewing. Just don't expect the show to get renewed for another season.