"Tunnel in the Sky" by Robert A Heinlein MMPB Vintage cover

Bagged for preservation this is a classic MMPB edition of a classic Sci_Fi Novel by the master of Sci-Fi.

From the author of STARSHIP TROOPERS comes TUNNEL IN THE SKY, the story of a group of students who are dropped on a foreign planet in order to test their survival skills. When the rescue ship doesn't arrive, they must create a new society and learn to adapt to their new life in the wild… but are their greatest troubles from beasts or fellow man?