project
Make and Code a Light-Powered Device
Design and assemble a light-power device modeled after the solar panels used to power spacecraft. You'll consider the challenges of collecting light and how to monitor your success, such as how to aim your device to collect the most light while avoiding overheating.
Materials
1. Learn how NASA uses light to power spacecraft
One of the ways that NASA powers its spacecraft is using light from the Sun, which within certain distances can provide a nearly infinite source of energy. However, the spacecraft solar panels that collect this light need to be very efficient and sometimes very large.
Missions such as Psyche, which is launching to the asteroid belt between Mars and Jupiter in 2022, or the Juno mission to Jupiter rely on large solar panels. This is because they travel long distances from the Sun, so their solar panels need to be able to collect any light available deep in the solar system to stay operational for multiple years.
About the image: These side-by-side graphics are artists' depictions of the Psyche spacecraft (left) and Juno spacecraft (right). Both spacecraft have large solar panels called "arrays" that allow them to travel great distances, where light from the Sun is faint. + Expand image
2. Brainstorm your own solar-powered device
Your goal in this activity is to create a device that can capture light energy and orient itself in the most optimal location to collect it without overheating.
You’ll want to be sure your device can detect a higher light and temperature level than is naturally available in the room, so pick your parameters carefully!
In the steps below, we'll walk you through some of the key components to consider while creating your device but the build and code is ultimately up to you. Before you get started, it might be helpful to do a little brainstorming about the design and key functions of your device to envision what a successful light collector might look like and anticipate potential challenges.
+ Expand image
3. Familiarize yourself with your coding dashboard
Different microcontroller or robotics kits will use very different dashboards, but there are options for any coding level. More advanced devices, such as raspberry pi, may use python, whereas others, like LEGO, use block coding. Kits like Cubit allow you to use a bit of both.
Feel free to use whichever you’re most comfortable with. Just be sure you have a computer capable of making edits and revisions, as we’ll want to be able to edit our system for different environments and applications. (Note: The example code shown throughout this activity was created with a Cubit microcontroller system.)
4. Arrange your sensors and tools
Create a structure to serve as the foundation for and surface of your light-powered device. For example, you can tape your sensors onto a piece of paper and attach that to a servo motor that can be rotated using your code.
If you have a more advanced kit, it may include an actual solar cell. If so, consider using that and connecting a light bulb via a small wire or including an ammeter to determine how much light energy you’re collecting.
+ Expand image
5. Set an initial position
To begin, we’ll want the device at a known position. This way, when we move from this position or want to reset, we'll always begin from the same location.
+ Expand image
6. Program a lux meter and its conditions
One critical piece of your design will be a lux meter, or a measure of how much light you're collecting.
Program a lux meter into your code and test it under various conditions, such as when the device is exposed to just the background light in the room versus when a light is shined on a sensor. This will help you determine whether your lux meter is working properly.
Consider adding a visual readout, such as an LED that indicates whether you are collecting the desired amount of light.
Be sure to introduce a "wait" operation so that you have time to see the results before your program moves on to the next step!
+ Expand image
7. Program a thermometer and its conditions
You will also want to create a process for measuring the temperature of your device to be sure it’s not getting too warm.
As before, test your thermometer by seeing how it handles under various conditions. For example, you can use a small lamp to increase the temperature on your device and see how the thermometer responds.
+ Expand image
8. Determine operations for both failure and success
Regardless of whether your device is collecting light and staying at the right temperature on your first try, you should continue to check and recheck your measurements.
Be sure that your program is set up to loop back to the beginning if the light and temperature measurements are acceptable. This will depend on how bright and warm it is in the room while you build. If you’re not reading more than the ambient light and temperature, then program the servo to move to a new position until it reaches an optimal location.
Verify the success of your code and assembly by moving the position of your light source and confirming that the apparatus now moves to the more desirable location for collecting energy.
9. Build in more measurements!
Your microcontroller or robotics kit may have other sensor tools that you can include. What other measurements are available that you think may be important to monitor?