chunk: The novel concerns people with incurable injuries and defects (biocompensators) who volunteer for the first interstellar flight.Turned down by the medical authorities, they are refused after they steal a ship to plead their case directly to the people of Earth. Returning to their asteroid hospital, they rig a working gravity drive and escape from the solar system. They head towards the Centauri system, solving problems such as overcoming a limited supply of needed pharmaceuticals and improving the drive. Earth sends out a ship, the Star Victory with a better version of the new drive in a bid to beat them there, on the theory that any aliens they encounter might make the mistake of thinking of them as normal humans. The Victory does beat them by a few days, arriving a year after they left, but they settle on a Mars-like planet near Alpha Centauri, before the Victory makes contact with butterfly-like aliens on a methane gas giant in the Proxima Centauri system. The aliens are somewhat