How are satellites tested, and how do they operate?

In this mission, we will put our designs to the test. Designing small spacecrafts for space environments requires rigorous on-earth testing, leading to many cycles of iteration. We will learn how to mimic some of these testing strategies (or create new ones!), as well as integrate our payload into the cubesats. These payloads will be the tools used to collect data in the final balloon launch!

✋ Multi-Session 🥰 Ages 8+ 🕐 1.5–2 Hours 👩‍👦‍👦 up to 20 Participants 🍎 1–2 Facilitators 🎨 Craft Materials

Selecting payloads and demonstrating payload outcomes

This workshop can be run in a few different ways: you can choose to provide one or multiple options for patrons to select payloads. For the easiest and lowest-cost version, space art is a great option (micro:bits are 'intermediately' difficult, and Raspberry Pis are the most advanced). If you are planning to provide patrons with the option of selecting payloads, you may need some advance time to tinker with the Pi cameras and micro:bits ahead of the workshop; there is no need to be an expert with these tools, but it can be helpful to have some familiarity and an idea of troubleshooting. The descriptions of each payload below link out to resources to help get you comfortable with the tech! Whatever payloads you choose to offer as part of the workshop, it is important to have some examples on-hand. Feel free to print the images we provide in this writeup (or show them via powerpoint), or create some of your own in advance of the workshop!

Setting up the workspace

Depending on your space, we encourage you to set up tables that sit between 4 and 6, with components for one payload at each. Materials for testing satellites (heavy books; string; duct tape) can also be placed at each table.

Payload materials

As a facilitator, it's up to you which payload materials you'd like to supply for your participants. You can select one, all three, or even come up with your own ideas!

Supply Kit

Introductory Activity: Space Environments and Satellite Testing

Suggested Timing: 20 minutes

Begin the introductory activity with a quick group brainstorm: why is it so challenging to engineer for outer-space environments? Satellite design and subsequent launch involves passing a number of tests that assess how well that spacecraft would fare in the harsh context of space. These tests aim to mimic the conditions observed in outer-space. Some examples include:

• The journey to space is a bumpy ride: cubesats are brought to space by rockets, which, in the launch process, undergo extreme amounts of vibration. Vibrational testing is completed to ensure that the satellite can withstand rocket launch before it is sent into orbit.
• Space is extremely cold—and extremely hot: space is thought of as very cold (and it is!), but satellites orbit the Earth, which means that they are also exposed to very hot temperatures (from the Sun and solar radiation). Testing the capacity to resist extreme heat and cold is called thermal testing.
• Space is full of junk: satellites in orbit are certain to encounter space debris, which might even include leftover satellites. They'll need to be structurally sound to withstand these interactions.

The most critical mission for a cubesat is to keep its payload (or cargo) in-tact and functional! This is also the mission of patrons. It's time to make sure that their designs can withstand the balloon launch: after the discussion, give patrons about 15 minutes to test their designs in at least three different ways:

• Drop test: stand on top of a chair, and then drop your satellite. See if it survives the fall!
• Shake test: Attach a piece of string (about 4 feet long) to two opposite ends of your satellite using duct tape or zip ties. Working with a friend, each grab an end of the string, pull it taut, and shake!
• Compression test: place 3–4 heavy, textbook-style books on top of your cubesat. See if it holds its weight!
• Encourage patrons to also come up with their own, new method of testing their design!

Based on the 'results' of these tests, they will have some additional time to re-engineer (if necessary) during the open build/payload activity.

Main Activity: Payload Selection and Integration (open build and test time)

Suggested Timing: 60 minutes

Patrons will have 60 minutes (or longer, depending on how you plan to run the workshop) to iterate on their designs, select and tinker with a payload, and integrate that payload into their cube-sat. Payloads are the data-collecting entities that are protected by the cube-sat exterior, as is the case here. Data can be collected by creating images; capturing images; using sensors; and more. Patrons should work in small groups to explore one of the following during balloon launch:

Space Art

Space art requires no 'technology' to collect data, and varies both by the way the paper used is folded or formed, as well as by the objects bound within the paper. This payload is inspired by the work of MIT Media Lab researcher, Ani Liu, who leveraged a zero-gravity environment to create a graphite drawing in outer-space. Patrons can put any marking tool (oil pastels, paint, etc.), and notice what marks are created while the payload is in the air. This payload scheme is easily tested before the launch, and so patrons can find out which materials they'd like to use when it's time to rig up their cubesats to the balloon.

Scratch + Micro:bit

A micro:bit can also be used as a payload, using Scratch to collect and show data. Micro:bits have a number of on-board sensors (including a gyroscope, thermometer, and photometer), which can be transmitted remotely from one device to another (to learn more, and get started, visit this link: scratch.mit.edu/microbit). We got creative with ours, by using Scratch to draw out a path of an astronaut using the micro:bit’s tilt data:

Scratch code for the project at scratch.mit.edu/projects/320744821/

Note that you will need two micro:bits per one satellite: one to act as the sensory payload in the satellite, and one to receive data remotely on-the-ground.

Infrared imaging with Raspberry Pi

Infrared imaging is one of the most common uses of satellites. This type of imaging allows you to see the Earth in new ways, and is often used to calculate the amount of plant growth (or vegetative index) in a given location. To experiment with infrared imaging, we use Public Lab’s Infragram Pi-camera: All the information you will need is on their website. Public Lab sells kits with all the necessary components, or you can buy them individually (see materials list). For the workshop, if using pi cameras, ensure that you have enough mobile batteries charged so that patrons can test the weight of their total payload.

Note: Something we’ve run into while having multiple pi-cameras is that each camera has the same wifi name (00-PiCam). This means that cameras might reconnect to different computers randomly. This is something the Public Lab community and we are working on! Stay tuned…

…And Beyond!

We’re curious to play with more payloads, whether it be different sensors (e.g. air quality), or different boards (e.g., Arduino). Please share with us if you try something else!

Workshop Musings

• Why do satellites need to be tested? How are they tested?
• What are some ways to test our satellites on Earth?
• What is a satellite payload? How are they integrated?
• What are different payloads used for?