The review guide states that the review is to be relevant to the content and/or context. In this case, they're two rather different reviews. Personally, I find Zubrin's Mars Direct/Mars Colony plan (the content part) flawed in quite a few ways, here are a couple: 1) the "frontier spirit" arguement is used often, and I agree that humanity is at its best when challenged and exploration and colonisation certainly serves this goal. But the specific case for Mars, as opposed to the moons of Saturn/Jupiter, asteroid belts etc are not made. 2) Assumptions about the industry of a Mars colony, deuterium mining for use in fusion for example, are founded on an unproven theoretical industry and also, due to the prevelance of Helium 3, encourage a settlement on the moon instead. Asteroid mining is posited but this is an arguement for mining asteroids, Mars is superfluous to this. 3) The Mars Direct mission itself is a tight rope and although Zubrin convincingly deals with many of the dangers the book is, perhaps necessarily lean on specifics regards crew details (men? women? age?) and logistic details, I personally doubt the craft has enough space for food, water, spare parts etc although I happen to know many of these details have been worked out at later dates, the crewing level has now been raised to 6, those ammendments are not present here. And on and on. However, Zubrin is making a case, not a watertight arguement and would doubtless concede that the debate is far from over so, in the spirit of the context side of the review I would say buy this book, absolutely, the Mars Direct plan is an excellent, ingenious basic idea that deserves publicity and this book should be bought and debated by scientists, students, policymakers and the general public alike.