How We'll Live on Mars (TED Books)
This book has plenty of good information and speculation with only a few errors. This is a topic that is extremely difficult to write about without making any mistakes at all. It's quite possible to write accurately one day and have that accuracy destroyed by new developments and discovery before actual publication. It's hard to explain to those who have not tried, the incredible breadth of knowledge required to discuss travel to and living on Mars unless that person has attempted it. As one who has essayed this effort in both fact and fiction (see ETCJournal.com and Mars Rhapsody), I can tell you it's a tough job. This book does the topic reasonable justice.
This book is designed to be read in a single sitting. As a result, it often does not plumb the depths of some topics. Quite a bit of the book details the history of the ideas of travelling to Mars, beginning with Wermer von Braun (pronounced: Verner fawn Brown).
Petranek covers the psychological, economic, and physical issues involved in getting to and living on Mars rather completely. He spends some time on Mars One and Elon Musk, suggesting that the former is a very long shot due to funding issues (I agree) and that the latter is almost guaranteed to succeed for a variety of reasons (I agree again). He spends a bit too much space on slamming NASA, albeit with some good reasons. He even indicts Richard Nixon as the primary person responsible for us not reaching Mars already.
As to the errors, they are relatively minor compared to the scope and thrust of the book. For example, the author writes, "When you run out of oxygen in a space suit, you can only breathe the carbon dioxide that you exhale for so long before you lose consciousness." In fact, you will die of carbon dioxide "poisoning" long before you use up the oxygen. Assuming that you are breathing regular air, oxygen is 20% of the content, and carbon dioxide is much less than 1%. By the time CO2 reaches 5%, O2 has dropped to just 15% because one CO2 molecule is produced for each O2 used. You have used up just 1/4 of the O2 available and are dead.
Petranek is very correct about no animals on Mars. They are much too inefficient as a source of food. He remarks that early Martian settlers will be vegetrarians. They'll actually be vegans, meaning that special attention must be paid to vitamins D and B12. These are available from sources such as yeast, lichen, and mushrooms. He also says that settlers are unlikely to produce more than ten percent of their own food. This pessimistic view contrasts strongly with some of his other optimism. Advances in genetic engineering, aeroponics, and fast hybridization should alter this forecast considerably. Self-suffciency is not just nice, it's a necessity.
The remarks on radiation are fairly accurate. Everyone should understand that radiation in space is about twice as harmful as that on Mars because cosmic rays come from all directions and are shielded from half of the cosmic sphere by Mars itself. Solar radiation also is shield half of the time, nighttime, by the planet as well.
Another pervasive issue is oxygen and atmospheric pressures. We have to have an oxygen partial pressure of around 150 millibars or so to survive. This is the pressure at the highest cities on Earth and is less than 1/6 of the pressure of the Earth's atmosphere at sea level. Even if the entire atmospheric pressure were this low, your blood would not boil. Other physiological processes may not be so amenable to low pressures. However, we should find out how low the pressure can go if we keep the partial pressure of oxygen constant at 160 millibars. Lower pressures mean lower construction costs and also have strong implications for terraforming Mars. In my book, Mars Rhapsody, I took the most optimistic view that you could live at 160 millibars of total pressure with all of it coming from oxygen.
The suggestion that plants can convert the CO2 into O2 in adequate amounts is way off. Mars has maybe 8-10 millibars of CO2. Converting it all to O2 would produce only that amount of oxygen, which is 20 or so times to low. Bacteria, lichen, and plants cannot "fix" Mars alone. We must have a much greater souce of O2. However, genetic engineering humans may be possible to make tolerating high CO2 levels and surviving with low O2 levels possible, but not without lots more O2 than you can get from plants.
The potential for genetic engineering humans to make them more radiation resistant, able to eat and metabolize plants that grow on Mars, making them able, perhaps by making them smaller, able to subsist on a limited diet, and allowing them to breathe much thinner air is explored in the book. The question not addressed is when these altered humans become a different species. What if we populate Mars to save our species but do so in such a way as to create an entirely different species? Earth humans, as we know them, may not be able to emigrate to Mars after all.
More discussion would be nit-picking. There's plenty in this book to recommend it. No one, even me, gets this entirely right, and no one knows all of the answers or even all of the problems. For a quick overview of how we'll get to Mars and how we'll live there, this is a very decent essay.