Landing Safely on Mars: An Integrated Unit Highlights Engineering Practices
Merritt, Eileen, Shifflett, Elizabeth, Science and Children
Helping students understand the complex relationships between our planet our nearest star, and our only satellite is a challenging task. It can be difficult to teach students about objects in space that are far away and impossible to touch. In fact, even many teachers have difficulty explaining the reasons for seasons (Kucukozer 2008). We found that reading nonfiction trade books, modeling relationships using everyday objects, and synthesizing ideas through writing and drawing helped our students improve their understanding. An added benefit of the integration was that teaching about the solar system during language arts freed up time in our schedule to introduce students to the complex world of engineering in science class. While designing and building "Mars landers," fourth-grade students engaged in important engineering practices such as making models, testing designs, and comparing the effectiveness of different models (NRC 2011). Students created nonfiction books as they learned about different objects in the solar system. Below we describe the distinct, yet related parts of our integrated unit.
Building Models of Mars Landers
During the first week of the science unit, students spent science time learning about Mars and researching the history of spacecraft that landed successfully (or not so successfully) on Mars. During language arts, students read and wrote about Earth and made Venn diagrams comparing the planets. We wanted students to understand why Mars might be an interesting place to explore, but a difficult place to inhabit. Also, to prepare for the upcoming engineering task, they read books about the Mars Pathfinder and answered questions about the goals of the mission and the design of the spacecraft. They visited the NASA website to look at video clips of a simulated landing and drew pictures on sticky notes to show the landing sequence (Figure 1). Students enjoyed watching a DVD that showed engineers and scientists discussing design problems and failures (Arizona Public Media 2007).
At the beginning of the second week, students were given the task of designing spacecraft that would be launched (from our gymnasium roof) and land safely on the surface of Mars (our school parking lot) with functioning scientific equipment on board. Students worked in mixed-ability groups to create a plan for their spacecraft (Figure 2). Large maps of Mars were displayed in the classroom, and students selected where they would like their spacecraft to land based on the research questions they hoped to answer when they "landed." They also selected what type of scientific equipment would be needed to carry out the research. Students included models of equipment such as cameras, drills, weather instruments, solar panels, and even rovers. All of the planning for the landers occurred in the days leading up to construction of the models. After great anticipation, students began building their models with materials collected from home and school. The goal was to have the spacecraft arrive safely at its destination with all of the model equipment intact.
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Watching the young scientists try out ideas and share strategies was a highlight of this unit. Many groups used parachutes (crafted from old sheets or garbage bags) to break the fall, whereas others tried air bags (such as bubble wrap or pillows) to cushion the landing. Students grappled with important engineering concepts as they experimented with parachute size and materials, models of air bags, and shape and weight of the landers. They "piloted" the landing by climbing to the top of the playground slide (supervised by a teacher) and tossing them in the air. Adjustments were made after observing the landing from a short distance. The day before the launch, students presented their models to classmates and described their research questions and equipment. …