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By Caitlin Davey 1 hour
Grades 4-6
Science and Technology,
  • Programming
  • Technology and Society
  • Design
Tools & Languages

Key Coding Concepts

  • Conditional Statements
  • Events
  • Loops
  • Parallel Execution
  • Variables



Pulling out specific differences to make one solution work for multiple problems



Making decisions based on conditions i.e. if some condition is met do something, else do nothing or something else



One thing causing another thing to happen i.e. ‘when clicked’ block



Running the same sequence multiple times i.e. repeat or forever blocks


Parallel execution

Making things happen at the same time



Stores a piece of information i.e. score of a game that increase by 1 value for each goal

In this activity, learners will imagine that they are Chris Hadfield remotely controlling the Canadarm2. They will use Scratch to create a simulation in which they put a new module on the International Space Station.

This lesson was made in partnership with

Minds On

Watch this video of Chris Hadfield:

Ask: What do we know about the International Space Station?


Building the International Space Station (ISS) is no easy task! The crews of the ISS have to attach modules weighing tons, extend solar panels longer than a bus, and haul equipment to and from the space shuttle.

Canadarm2 is a Canadian-made robotic arm located on the International Space Station (ISS) that helped astronauts such as Marc Garneau and Chris Hadfield build the ISS in space. Since 2001, the 17-metre long Canadarm2 has been helping move equipment, supplies, astronauts, and even spacecraft such as SpaceX’s Dragon capsule around the ISS.

In the International Space Station (ISS), actions have to be done in the correct order to place modules where they need to go on the ISS. It will be a “lock & key” fit, so that the piece must go on properly in order for it to work.

Watch the Hadfield behind the controls of Canadarm2 video:

  • Q: In what ways is the Canadarm2 used on the International Space Station?
  • Q: Where is a good place to go to control the Canadarm2?
  • Q: Why are there so many cameras to help guide the astronaut when controlling the Canadarm2?
  • Q: What are some of the challenges of using a robot such as the Canadarm2?

Using Scratch, we are going to create a game where we control Canadarm2, just as Chris Hadfield did in the video.

Code Along

  1. Open up a new Scratch project at and click on “create” (top, left corner).
  2. Point out the main elements: Stage, Sprites, and Scripts. Demonstrate how to drag and connect blocks.
  3. Give learners a few minutes to click on blocks and explore.
  4. Go through 1-2 challenges with the group, where learners are tasked with trying to make something happen in Scratch. For example, “Try to make Scratch move” or “Try to make Scratch say something when the space key is pressed” (See the Code-Along Challenges doc for more examples and solutions)


Show the example project so learners know what they are working towards. Press the green flag to start, use the arrows to move Canadarm2, and the spacebar to pick up and release objects. Don't reveal these instructions to the learner - instead ask them what they see/hear. What is happening in this project?

Open the starter project and review the Sprites and backgrounds.

Have learners open the starter project on their screens and click "See Inside" or “Remix” (The remix button will only be visible once they are signed into their accounts.)

Use the solution sheet to guide learners through the following steps:

  1. Make the arm move
  2. Reset the arm’s position
  3. Open and close the claw
  4. Pick up the modules
  5. Place modules on the port
  6. Reset the modules’ positions
  7. Copy instructions to remaining modules
  8. Any Add-Ons, if time

Learning Outcomes

I can create algorithms in Scratch
I can use conditionals to control what happens in my project
I can use loops to make things happen more than once
I can use events to control when things happen in my project
I can use broadcast messages to communicate between sprites in my project


Success Criteria

I remixed the starter project and renamed it with my first name.
My Canadarm2 can be controlled by the player.
My Canadarm2 can collect and sort modules.
I used broadcast messages to communicate between elements in my game.

Assessment Ideas

Use Comments in Scratch for learners to explain their steps (right click > add comment).

Learners could create a flowchart (see this flowchart template!) or sequence of steps using mathematical language before building the game in Scratch (e.g., turn 30⁰ clockwise, travel forward 3 cm, turn 60⁰ counterclockwise, etc.)

Design: Discuss elements of visual design and game design used in this project that enhance the player’s experience. Ask learners to discuss what changes in the visual design components or game design components of the project would improve the game for a specific audience (e.g. adding sound or adding scoring).

Language: Have learners write a first-person account of an astronaut using the Canadarm2 to successfully capture a Dragon or Cygnus capsule.

Watch this video to learn about the 40 years of robotic innovation that Canada has made, including the Canadarm!

Teach lessons that are tied to your existing curriculum!


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    The K-12 Computer Science Framework

    Although learning how to build digital projects is a key part of Computer Science education, students should also learn a wider set of skills and competencies that will help them to harness the power of digital technologies as both creators and consumers. A comprehensive approach to K-12 Computer Science education includes learning about the following five focus areas:

    View Framework ➝


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