Let's hold it down. The only engine we got with enough power for a direct abort is the SPS on the service module. From what Lovell has told us, that could have been damaged in an explosion, so let's consider that engine dead. We light that thing up, it could blow the whole works. It's just too risky. We're not going to take that chance. About the only thing the command module is good for is reentry, so that leaves us with the LEM, which means free-return trajectory. Once we get the guys around the moon, we'll fire the LEM engine, make a long burn, pick up some speed, and get them home as quickly as we can.
— Apollo 13
by Ron Howard