They entered the wilderness as prepared as possible. However, these endeavors occurred in an arena where there are a nearly infinite number of possible trivial, but fatal, mistakes. Endless computer simulations can eliminate 99.999 percent of the predictable mistakes, but as history has proven, unforeseeable quirky mistakes cannot be simulated. Too high of a voltage applied during one test of an Apollo cryogenic tank nearly doomed Apollo 13. Careers will end and investigations will find causes, but there is simply no way to totally eliminate the threat of the infinite number of quirky, but fatal, scenarios that plague physical exploration.
Explorers can and do enter the wilderness and accomplish their missions unscathed.
Lewis and Clark crossed the North American continent and lost only one man to appendicitis. But the mission was gone so long that President Jefferson wrote the entire expedition off as a failure. Lindbergh did cross the Atlantic solo in an airplane, but others who attempted the feat before him disappeared without a trace into the Atlantic. Today we remember solo space explorers such as Lunar Prospector and Mars Pathfinder that entered the wilderness and accomplished their missions and more. Their success was the result of hard work, endless simulations, quality redundant equipment and a good dose of luck.