Critic and engineer Gary Westfahl has said that because the proposition depends upon systems that were built without enough margin for error, the story is good physics, but lousy engineering, and that it frustrated him so much he decided it was "not worth (his) time. Very poor Engineering." Writer Cory Doctorow has made a similar argument, noting that the constraints under which the characters operate are decided by the writers, and not therefore the "inescapable laws of physics". He argues that the decision of the writer to give the vessel no margin of safety and a marginal fuel supply focuses reader attention on the "need" for tough decisions in time of crisis and away from the responsibility for proper planning to ensure safety in the first place. Doctorow sees this as an example of moral hazard.