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STEM Book Club: The Nebula Secret

For this months STEM book club, I decided to go with an action adventure book all about explorers.

Explorer Academy: The Nebula Secret by Trudi Trueit is the first book in a new juvenile adventure series.

Cruz is one of 24 kids across the globe that has been chosen to attend the elite Explorers Academy. Taught by leading researchers, wildlife experts, survivalists and conservationists, Cruz and his fellow explorers are training to become the next generation of great explorers.

But for Cruz this is more than just a dream, this is his legacy. When his mom died when Cruz was just a boy, he knew he would follow in her footsteps at the academy. But no sooner then he receives his acceptance letter, do weird and dangerous “coincidences” seem to dog him.

Can Cruz handle the pressures of Explorer Academy and can he find out who is out to get him and why?

Discussion Questions / Further Reading 

  1. What is this book about? What are the main themes? 

  2. What do you think about Explorer Academy? Would you like to see an institution like this? How would a place like this help in today’s environmental struggles?

  3. Explorer Academy is extremely competitive, but Renshaw tells Cruz, “My brother says … everybody helps everybody else. The teachers encourage that.” [Page 40] How do you feel about this—knowing that with your help, another student might succeed over you? In this kind of environment, would you hesitate to help a classmate? Why? Why not?

  4. We saw a lot of different “tech” in this book—some of it real and some of it embellished. What was your favorite technology in this book and why? 

  5. The young explorers are required to wear their OS bracelets at all times. What if the band was available to the general public? What would the benefits be to the health and well-being of the people wearing it? What if people were required to wear it? In what ways could this seemingly beneficial device be abused by an agency responsible for viewing and using its data?

  6. Why is it so important for Explorer Academy students to study “the characteristics of humanity—why different cultures eat, speak, dress, think, believe, live, and act the way they do.” [Page 111] How will knowing this enhance their experience as explorers?

  7. The CAVE is a major part of the explorers training. What did you think about this method of training? How far away do you think current technology is toward this goal? 

  8. What is “Cryptography?” Give a few examples of how cryptography was used in this book.

  9. MAV was Cruz’s robotic honey bee. If you could design your own MAV what would it look like and why?

  10. This is the first book in a seven book series. Do you have any predictions about where this series could be heading? 

DIY Cipher Wheel


Supplies: Cardboard; Scissors; 1 brass tack; markers; template; glue.

A cipher wheel is an enciphering and deciphering tool developed in 1470. It consists of one stationary wheel and one “moveable” wheel. A cipher wheel can code and decode messages as long as one has the cipher key. There are many variations of cipher wheels but today we are going to do a basic substitution cipher.

How To:

  1. Using your template, cut out the two circles.

  2. Trace your circles on cardboard and cut them out as well.

  3. Glue or tape the template to the cardboard.

  4. Place the smaller circle atop of the larger one. Carefully using a scissor or pen, poke a hole in the middle of each circle.

  5. Take your brass tack and secure the two cardboard circles together. The circles should still be able to move.

  6. Your cipher wheel is ready for use.

  7. To use your wheel, decide which letter on the smaller circle will be your cipher key. Let’s use “R” as an example. Turn your wheel so that the letters A, on the big wheel, and the letter R, on the smaller wheel line up.

  8. You can now write your messages in code and give the cipher to those you want to read it.


  1. You could also create a cipher wheel with symbols on the smaller wheel.

  2. How else could you use a cipher wheel?

  3. Can you think of other ways to decode and encode messages?


How’d it go:

This one went pretty well. It was a “cleaner” and easier STEM activity then some of my others, so I wasn’t scrambling to help 20 kids at once. We finished a little early, but overall it was a successful program.

That’s all for now!


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