text: In an otherwise good review, loleralacartelort7890 says "The truth is that the Americans use a secret aluminum-anti-radiation-alloy. It is not that well-known. And the exact specifications are a secret. And why is it a secret: Well, why should they reveal it back then?? If they where in a space race with the Russians, then it would be VERY dumb to reveal that they had new technology that could shield crew against radiation." This is completely incorrect. There is (and was) no "secret" to radiation protection in Apollo. The design and construction of the Apollo Command Module has long been publicly available. It uses a lightweight "honeycomb" of aluminum and stainless steel. The entire outer surface (except the windows of course) is covered with a heat shield made of a phenolic resin, thicker on the bottom that faces forward during re-entry. These materials are actually *better* at stopping the kind of radiation we have in space (charged particles) than lead, which is better suited to stopping ionizing photons like X-rays and gamma rays.<br /><br />Space radiation is a definite problem for *long term* space flight because of the risk of big solar flares. But it simply wasn't a serious threat to the Apollo astronauts. The Command Module gave them pretty good protection during their brief (1/2 hour or so) passage through the Van Allen belts. They all carried dosimeters so we know exactly how much radiation they each received: no more than 1.5 rem, and usually much less. Of the 24 men who flew to the Moon (12 of whom landed), 18 are still alive. Only two have died from cancer: Alan Shepard (leukemia) and Jack Swigert (bone cancer). The rest died from heart attacks, pancreatitis (Roosa), and a motorcycle accident (Conrad). These are actually pretty good statistics for a group of men now in their late 70s (Shepard would be 86).