DESIGN A HEAT SHIELD
Today we will learn about the technology used on spacecraft to protect astronauts and the vessel from the heat!
Before we start, let’s reflect on these questions:
The USS Intrepid is an aircraft carrier that served from 1943-1974
What is friction?
Try this!
You probably observed the heat as you rubbed faster and faster.
Image credit: twinkl.com
The USS Intrepid is an aircraft carrier that served from 1943-1974
What is friction?
There are some scientific things happening when you rub your hands together. First, the rubbing causes a scraping the surface of your skin as you move both hands back and forth against each other. This causes the molecules in your skin to move a little faster. As a result, the temperature increases when the molecules move faster and faster. That is how the friction of rubbing your hands together makes them feel warmer.
Let’s apply this thinking to protecting people in space.
Image credit: twinkl.com
What is happening to a spacecraft when it launches into space or returns from space?
Take 30 seconds to look all around the image to the right. Look to the top, the bottom, the left and the right.
Without talking, use your eyes to make silent observations. Then turn and talk with a partner to share what you noticed.
Photo Credit: NASA
What is happening to a spacecraft when it launches into space or returns from space?
Perhaps you shared some of these observations:
Now that we have shared some observations, let’s think about how this object applies to protecting spacecraft and astronauts in space!
Photo Credit: NASA
What is happening to a spacecraft when it launches into space or returns from space?
Just like the action of rubbing your hands together, spacecraft and their astronauts are experiencing extreme friction, or drag, as they are launched into space. This also happens when re-entering Earth’s atmosphere.
Astronaut Scott Carpenter (right) went up on this rocket and experienced this heat. His space suit helped protect him from many things, but more was needed for nearly 3,000 degrees Fahrenheit!
Photo edit: NASA
Photo Credits:
NASA
How can we design something to protect astronauts and spacecraft from the heat?
The image on the right is a Mercury space capsule, named after the planet. It did not go to Mercury.
The Mercury capsule tested the ability to safely send the capsule and Scott Carpenter into space. This happened before NASA sent astronauts to the moon.
Can you think of something needed on the outside to protect the vessel and its astronaut from the intense heat?
Photo Credit: Intrepid Museum
How can we design something to protect astronauts and spacecraft from the heat?
The heat shield on a Mercury’s curved bottom helped protect the Scott Carpenter as the vehicle re-entered the atmosphere.
With each type of capsule, the heat shield technology advanced. For this Mercury capsule, honeycomb-shaped aluminum, mixed with layers of a glass-fiber material, made the heat shield. It boiled away as the capsule re-entered Earth’s atmosphere, leaving a white residue on the surface that resembled icing.
Photo Credit: Intrepid Museum
How can we design something to protect astronauts and spacecraft from the heat?
With the space shuttle program, the idea of a barrier to protect the spacecraft and its crew continued to evolve, just as it did for the capsules.
Space shuttles used tiles, like the one you see on the top right. Each tile requires specialized tools to produce precise shapes to match each spacecraft. These are carefully tested in lab facilities.
Photo Credits: NASA
How can we design something to protect astronauts and spacecraft from the heat?
There are two main types of tiles for the shuttles. One is a black tile specifically for protection against high temperatures. These tiles can withstand up to 2,300 degrees F (1,260 degrees C) and cover the bottom of the shuttle, areas around the forward windows, and several other key areas. White tiles are designed to insulate up to 1,200 degrees F (650 degrees C).
Making these tiles begins with pure silica and sand. The mixture of chemicals are baked in a large microwave oven.
Photo Credits: NASA
How can we design something to protect astronauts and spacecraft from the heat?
Watch astronaut Mike Massimino talk about the tiles in the video to the right.
Video Credit: Intrepid Museum
How can we design something to protect astronauts and spacecraft from the heat?
Now that you know about thermal protection tiles on spacecraft, you will now become an engineer. Your task is to design a way to protect a chocolate astronaut from melting from the heat.
Look at the graphic on the right. This cycle of steps will guide you. What do you notice?
Graphic Credit:
TeachEngineering.org
How can we design something to protect astronauts and spacecraft from the heat?
Start by asking questions. What problem are we trying to solve? We want to protect our chocolate astronaut from melting by designing thermal protection. How can we do that?
You will have some limits and need teacher supervision. See Handout 1 to get going!
Graphic Credit:
TeachEngineering.org
REFLECTION