Tunnel in the sky

Tunnel in the Sky came out in 1955 as one of the novels Heinlein wrote for younger readers under the Scribner's imprint.

Its future is one in which the pressure of population on Earth has been relieved by a method of teleportation known as the Ramsbotham jump, which lets the surplus population settle other planets. Colonies stay cut off from Earth until they can produce something worth trading, and because advanced technology needs a supporting industry behind it, they make do with equipment no more modern than that of nineteenth-century pioneers.

Rod Walker is a high-school student who wants to be a professional colonist, and the last examination of his advanced survival course is to stay alive for somewhere between two and ten days on a planet he has never seen. The students are allowed to work in teams and to carry whatever they can manage, and they are told only that the problems they meet will be neither impossible nor unfair. When the test begins, the group finds itself more alone than any of them expected.