Until Stargate Universe's episode five, "Light," we still see the crew of the Ancient ship Destiny as military and civillian, almost always working at cross purposes and in conflict. There is zero trust between Dr. Nicholas Rush (the brilliant Robert Carlyle) and de facto Mission Commander Col. Everett Young (Louis Ferreira). In "Light" we finally see them, of necessity, beginning to trust each other, at least minimally—and temporarily—and only of necessity. But it's a start, and in the end, critical for all of their survival.
At the end of episode four, "Darkness," Destiny, still on autopilot, had performed a narrow breaking maneuver and changed its course, heading right for a star. With still little understanding of the Ancient ship's systems, Rush is at a loss to explain what's happened. He must have theories, but he's not shared them with anyone. My guess is that he suspects that Destiny might use the stars to power itself, but I'm also guessing he believes it's just a hunch—a gut feeling; something he's not yet willing to share.
The crew members are faced with seemingly inevitable death; the ship will dissolve into the star and everyone on board her will perish from heat, gravitational forces and the eventual breakdown of the ship's hull. We see how each one of the main players react to this inevitability, and perhaps more than in the first four episodes, we begin to know them.
When Destiny drops out of its faster than light (FTL) mode, it does so in range of three planets, one of which seems at least minimally habitable. This appears to be the ship's MO in understanding the crew's needs, as well as the ship's needs. They haven't the power to use the stargate, so the only choice they have is to use the shuttle to transport down to one of the planets—the one Rush believes can support life. The "Goldilocks" planet, he calls it—not too hot, not too cold.
The shuttle, fully loaded with supplies, can only hold 17 passengers. But there are 80 or so crew members aboard Destiny, so how to choose? And who to choose? Young decides on a lottery system to select 15 of the 17, reserving two spots for himself to choose.
Removing himself from the lottery, Young selects the only other qualified pilot, Matthew Scott (Brian J. Smith), and medic T.J. Johansen (Alaina Huffman). Scott is also Young's second in command and, although he's inexperienced, he has already shown some leadership skills, even if he's not an exceptionally brilliant mind. These are both good choices, if the survivors have any chance of making a go of it on the planet.