Thermal Protection Systems: Day 2 and Day 3

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Objective

Students will be able to apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.

Big Idea

Students use their knowledge of radiation, conduction, and convection to design thermal protection systems for NASA that will protect a spacecraft from burning up in the atmosphere!

Introduction and Connection to the NGSS and Common Core

This is part of a three day lesson in which students explore energy transfer as they use the engineering design process to design thermal protection systems that can prevent a spacecraft from burning up in the atmosphere.  This lesson is adapted from NASA Engineering Design Challenges.  Be sure to check out Day 1 of this lesson for more information on what leads up to this day!  The Day 1 Lesson Plan includes explanations of materials and set up.

This lesson is geared to address the following NGSS and Common Core Standards:

MS-PS3-3   Apply scientific principles to design, construct, and test a device that either minimizes or maximizes thermal energy transfer.

MS-ETS1-1  Define the criteria and constraints of a design problem with sufficient precision to ensure a successful solution, taking into account relevant scientific principles and potential impacts on people and the natural environment that may limit possible solutions.

MS-ETS1-2. Evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.

MS-ETS1-3. Analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.

MS-ETS1-4. Develop a model to generate data for iterative testing and modification of a proposed object, tool, or process

CCSS.ELA-LITERACY.RST.6-8.1  Cite specific textual evidence to support analysis of science and technical texts.

CCSS.ELA-LITERACY.RST.6-8.7 Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table).

CCSS.ELA-LITERACY.WHST.6-8.9  Draw evidence from informational texts to support analysis, reflection, and research.

CCSS.ELA-LITERACTY.WHST.6-8.2c Use appropriate and varied transitions to create cohesion and clarify the relationships among ideas and concepts.

Science and Engineering Practices:

As students go through the engineering design process, they create thermal protection systems that can survive traveling through the atmosphere.  In doing this, they apply scientific principles to design, construct and test a tool or system (SP6).  In addition, students obtain, evaluate, and communicate information such that an optimal design can be achieved (SP8).

Cross Cutting Concepts:

Designing thermal protection systems also can provide students with practice in Cross Cutting Concepts of “Systems and Models” as well as “Energy and Matter”.  Students use the thermal protections systems as a model that can show the input and output of energy and track how energy flows within the system (CCC Systems and Models).  As they observe the heat transfer in their various designs, they also notice that the transfer of energy can be tracked as energy flows (CCC Energy and Matter).

Connecting to the Essential Question: What are you going to learn today?

5 minutes

Remember - this is the second day of this lesson.  Be sure to check out Day 1 of this lesson for more information on what leads up to this day!

Ask students, "What are you supposed to be learning today?".  Students should respond with the essential question, "How does energy transfer through various systems in the natural world?" (I keep this posted on the board.  Students also have it in their Unit Plan).

Explain that the students will specifically be connecting to Skills 3, 4, and 5 listed in the Unit Plan:

3.  I can solve problems based on my understanding of heat transfer (conduction, convection, radiation).

4. I can provide evidence that the amount of energy needed to transfer to change the temperature (average kinetic energy of the particles) of an object depends on the type of matter and the mass of the object.

5.  I can support the claim that when the kinetic energy of an object changes, that energy has been transferred to or from the objects in the system (energy is conserved).

At this point, students have already self-assessed their level of mastery on a scale of 1 to 4 (4 being mastery) in the margin for each of these skills.  Ask students to reassess themselves and change their number if they feel like their level of mastery has grown.  For my students, this is the third lesson dealing with these topics. Thus, I also emphasize that if students feel like their mastery level is not progressing or if they are confused about any topics, now is the time to advocate for themselves and get the extra help they need.  Encourage them to ask questions as they work through this design challenge over the next few days to get themselves to a level of mastery they are working towards.

Then, ask the students to make as many connections during the lab to the following ideas/concepts:

  1. Conduction, convection, and radiation
  2. How the type of matter or mass of an object affects heat transfer
  3. How energy can be tracked through a system (that when one object gains energy, another loses energy)

Remind them if at any point during the lab they connect to any of these ideas, they should share that connection with you or a fellow student!

Day 2 Mini Lesson: Sound Like a Scientist and Using Transitions, Sorting Student Work

30 minutes

Cut the each of the student samples in this document into slips of paper.  Make enough copies for each pair of students to have a set.  Ask students to sort the slips in order of "Sounds Like a 7th Grader" to "Sounds Like a Scientist".  Once the students have sorted the slips, ask them to discuss their reasoning for their choices.

Rotate around the room and interact with students about their choices.  Students at the middle school level are very task driven; they will try to simply sort the stack without discussing their reasoning. And, this discussion is the key to the success of this activity.

Once students have ordered the student samples, have groups share for the class the reasons for their decisions.  

The key is that students begin to develop an understanding of the importance of a formal tone in scientific writing.  Students recognize that when writing in a formal tone they should use strong nouns and verbs (using science vocabulary, writing in the third person verses using words like it, them, they, I, we, etc.).

Below are some of the examples of what students may specifically say about each response.

 

Lab Question:  What is the relationship between the temperature of the solvent and the rate of dissolving of a solid? Explain.

Student Response #1:  The rate of dissolving increased when it got hotter.  The molecules move around and bump into each other more.  It went faster in the hot water than in the cold water.

Student Critique:  The students typically share that this response "sounds like a 7th grader" and often rank it last of the group.  Students mention that this response does not use strong vocabulary with words like 'it'.  After looking at the other responses, they also notice that there is a lack of "flow" in this responses because the response does not include transitions.

 

Lab Question:  What is the relationship between the temperature of the solvent and the rate of dissolving of a solid? Explain.

Student Response #2:  As the temperature increases, the rate of dissolving increases.  This occurs because the molecules move around faster and bump into each other more.  In this experiment, this was shown when the sugar dissolved faster in the hot water than in the cold water.

Student Critique:  Students typically share that this response "sounds most like a scientist".  Students note strong vocabulary and the use of transitions.  Even students that may not know the word, "transitions" may mention that the phrases "as the temperature increases," "this occurs because", and "in this experiment" help the response flow.  Help students recognizes that these phrases that take the reader from one sentence to the next are called transitions.

 

Lab Question:  What is the relationship between the temperature of the solvent and the rate of dissolving of a solid? Explain.

Student Response #3:  As the temperature increases, the rate of dissolving increases.  The molecules move around and bump into each other more.  The sugar dissolved faster in the hot water than in the cold water.

Student Critique:  The students typically share that this response "sounds like a 7th grader" and often rank it last of the group.  Students mention that this response does include strong vocabulary, but it just doesn't "sound as good" as Response #2.  After looking at the other responses, they also notice that there is a lack of "flow" in this responses because the response does not include transitions. 

Day 3 Warm Up: What are your go-to transitions?

10 minutes

On the board draw a light bulb with the question, "What are your go-to science transitions?" written inside.  With "light rays", have the students come up and write their favorite transitions to use in science writing.  Once the day is finished, compile these into a document for students to keep in their binder so that they always have a reference for varied transitions.

Thermal Protection Systems: Testing Solutions

45 minutes

Remember - this is the second day of this lesson.  Be sure to check out Day 1 of this lesson for more information on what leads up to this day!

Here are some various design ideas and tests.  The designs that work utilize an air pocket as an insulator between the heat source and the metal screw.  Students typically begin with the first row of designs and then adjust and begin creating designs similar to the second row.

A look at the awesomeness of heat transfer with the blow torch!  Students love that it actually looks like the image they picture in their heads of a spacecraft entering the atmosphere!

Beware of designs that can "cheat":  Watch the video below closely.  While the design does not touch the dowel (as per the constraints), part way through this video, the screw actually becomes disconnected from the dowel due to the hot glue melting.  However, the tin foil "lands" on the dowel making it appear as if it is still attached.  If you leave a "detached" design in the flame for too long, the dowel begins to burn!

 

A look at some tests:  Note that I did not video them for the full 2 minutes of survival.  I just wanted to give you a visual idea of the process.

Thermal Protection Systems: Diagrams as Models

15 minutes

Remember that on Day 1 of this lesson, students identified their own criteria to rank their designs.  In this lesson I mentioned that students often choose criteria that are not the most important.  In this case, the students chose "ease of construction" and "materials fall away" as criteria.  As students go through the design process, they begin to realize that these are not priorities.  Thus the questions on the front of the lab document ask students to determine the criteria that are important.

In reference to the second question in the document below, the student identified that the most important criteria for a successful design includes the location of the insulators, the location of the conductors, and the portion of the design that is touching the flame.  In addition, the student has completed the data table below reflecting and analyzing the successes and failures of each design.

Students have been working on developing diagrams with a purpose, title, labels, and caption.  The first diagram asks students to identify where radiation, conduction, and convection were occurring in the TPS.  It is important that the student includes an appropriate title, labels all three types of heat transfer, and describes where each is occurring in the caption.

The second diagram asks the students to show how the type of matter in a system changes the amount of kinetic energy transfer.  In this case, students should again include a relevant title, label both insulators and conductors, and describe in the caption which materials transferred energy more readily than others.

Closure: Formative Assessment Exit Slip

10 minutes

Have students complete this formative assessment as an "exit slip".  

In this example, the student included a title, labels, and a caption that demonstrated how radiation, conduction, and convection work together to heat the atmosphere.  There are some things in this example that you should look for to identify misconceptions.  First, the student writes that "Radiation from the sun heats the air."  Students have a difficult time understanding how electromagnetic radiation works and that there is a variety of types of radiation that act differently.  Students need further instruction to understand that the light can travel without a medium and transfers into thermal energy once it is absorbed by the ground.  So, sunlight that passes through the atmosphere is not heating the air.  It must first be absorbed before it transfers to thermal energy.  Students are often not secure on this idea that the sun doesn't heat the air, the sun heats the earth.  The EM wave itself is heating the air is infrared radiation.  Conduction is one way that the air is heated.  Once the ground is heated by absorbing the EM wave, collisions between the ground and air molecules cause the ground to transfer energy to the air.  Also, in the caption, it is important that the student refers to each of the forms of heat transfer by name.  In this case, the student needed to include the term conduction.  The last bit of feedback I would provide the student is that while they stated that convection relates to currents, it would have been clearer to say something such as "a current of rising warm air and sinking cooler air."