Young Adult science fiction book, early 80's

Question

I am looking for the title of a book from the early 1980's, available through Scholastic Book Clubs.

It is a science fiction story about a human boy who goes to a training academy on a desert planet. They are taught to survive in the environment with minimal technology, and the heroes are often drinking from spongy water-filled tubers they find in the desert sand. The planet has very little in the way of visible life but lizards and specialised plants.

The academy's graduation test is to be dropped in the desert and find your way back to the academy. The boy is dropped in the desert with an alien humanoid classmate with silver skin. As this happens, they realise an enemy warship is scouting the planet and has possibly taken the academy over. They must detour across even harsher terrain than normal to reach a city to warn of the impending establishment of a forward base on the planet.

After much hardship, there's success and the usual happy ending with 'you graduate even though you didn't really finish the proper test' device.

Answer 1

Is it The Vandarian Incident by Martyn Godfrey?

I found mention of it on this old Scholastics order form.

Tyler, a cadet at an interplanetary space academy, must conquer sandstorms, scorching heat, and freezing cold to pass his last survival test mission. But the evil reptilian Vandors plan to destroy the galaxy first!

And from a review on Amazon..

This book is set in the future, where humans have inhabited other planets in our solar system. Two young students of the military academy are sent on a mission across barren and dangerous territory. A slight rivalry exists between them,and while on their journey they encounter problems.

Fortunately, these are overcome, their mission is complete and they are promoted to the next stage of their training. A brilliant story, though first printed many years ago. It is worth-while reading for 9 to 12 year olds. Godfreys builds up the plot with well planned suspense, and uses great descriptions to bolster the reader's imagination

Answer 2

It sort of sounds like "Between Planets" by Heinlein, but it's been a long time since I read it.