Students are challenged to design a permanent guest village within the Saguaro National Park in Arizona. The design must provide a true desert experience to visitors while emphasizing sustainable design, protection of the natural environment, and energy and resource conservation. To successfully address and respond to this challenge, students must acquire an understanding of desert ecology, environmental limiting factors, species adaptations and resource utilization. Following theintroduction, students generate ideas and consider the knowledge required to complete the challenge. The lectures and activities that follow serve to develop this level of comprehension. To introduce the concepts of healthy ecosystems, biomimetics and the importance of sustainable environmental design, students watch three video clips of experts. These clips provide direction for student research and challenge design solutions.

Students investigate circuits and their components by building a basic thermostat. They learn why key parts are necessary for the circuit to function, and alter the circuit to optimize the thermostat temperature range. They also gain an awareness of how electrical engineers design circuits for the countless electronic products in our world.

The Challenge Question of the Legacy Cycle draws the student into considering the engineering ingenuity of nature. It will force him to analyze, appreciate and understand the wisdom of these designs as the student team focuses on meeting each of the challenge's requirements. The student is asked, with his team members, to envision a sustainable design for a future guest village within the Saguaro National Park, outside of Tucson, Arizona. What issues need to be addressed to support the comforts of park visitors without compromising the natural resources or endangering the endemic species of the area? A deeper scope of application will reveal extensions of this design in the incorporation of urban planning and systems design. It also strengthens the concept of manufacturing and building without producing waste or pollution.

Students acquire a basic understanding of the science and engineering of space travel as well as a brief history of space exploration. They learn about the scientists and engineers who made space travel possible and briefly examine some famous space missions. Finally, they learn the basics of rocket science (Newton's third law of motion), the main components of rockets and the U.S. space shuttle, and how engineers are involved in creating and launching spacecraft.

Students are introduced to detail drawings and the importance of clearly documenting and communicating their designs. They are introduced to the American National Standards Institute (ANSI) Y14.5 standard, which controls how engineers communicate and archive design information. They are introduced to standard paper sizes and drawing view conventions, which are major components of the Y14.5 standard.

Students quantify the percent of light reflected from solutions containing varying concentrations of red dye using LEGO© MINDSTORMS© NXT bricks and light sensors. They begin by analyzing a set of standard solutions with known concentrations of food coloring, and plot data to graphically determine the relationship between percent reflected light and dye concentration. Then they identify dye concentrations for two unknown solution samples based on how much light they reflect. Students gain an understanding of light scattering applications and how to determine properties of unknown samples based on a set of standard samples.

Students use two different methods to determine the densities of a variety of materials and objects. The first method involves direct measurement of the volumes of objects that have simple geometric shapes. The second is the water displacement method, used to determine the volumes of irregularly shaped objects. After the densities are determined, students create x-y scatter graphs of mass versus volume, which reveal that objects with densities less than water (floaters) lie above the graph's diagonal (representing the density of water), and those with densities greater than water (sinkers) lie below the diagonal.

In a multi-week experiment, student teams gather biogas data from the mini-anaerobic digesters that they build to break down different types of food waste with microbes. Using plastic soda bottles for the mini-anaerobic digesters and gas measurement devices, they compare methane gas production from decomposing hot dogs, diced vs. whole. They monitor and measure the gas production, then graph and analyze the collected data. Students learn how anaerobic digestion can be used to biorecycle waste (food, poop or yard waste) into valuable resources (nutrients, biogas, energy).

To reinforce students' understanding of the human digestion process, the functions of several stomach and small intestine fluids are analyzed, and the concept of simulation is introduced through a short, introductory demonstration of how these fluids work. Students learn what simulation means and how it relates to the engineering process, particularly in biomedical engineering. The teacher demo requires vinegar, baking soda, water and aspirin.

The digestive system is amazing: it takes the foods we eat and breaks them into smaller components that our body can use for energy, cell repair and growth. This lesson introduces students to the main parts of the digestive system and how they interact. In addition, students learn about some of the challenges astronauts face when trying to eat in outer space.

Geographic information systems (GIS), once used predominantly by experts in cartography and computer programming, have become pervasive in everyday business and consumer use. This unit explores GIS in general as a technology about which much more can be learned, and it also explores applications of that technology. Students experience GIS technology through the use of Google Earth on the environmental topic of plastics in the ocean in an area known as the Great Pacific Garbage Patch. The use of this topic in GIS makes the unit multidisciplinary, incorporating the physics of ocean currents, the chemistry associated with pollutant degradation and chemical sorption to organic-rich plastics, and ecological impact to aquatic biota.

Students create model elevator carriages and calibrate them, similar to the work of design and quality control engineers. Students use measurements from rotary encoders to recreate the task of calibrating elevators for a high-rise building. They translate the rotations from an encoder to correspond to the heights of different floors in a hypothetical multi-story building. Students also determine the accuracy of their model elevators in getting passengers to their correct destinations.

Students design and conduct experiments to determine what environmental factors favor decomposition by soil microbes. They use chunks of carrots for the materials to be decomposed, and their experiments are carried out in plastic bags filled with dirt. Every few days students remove the carrots from the dirt and weigh them. Depending on the experimental conditions, after a few weeks most of the carrots will have decomposed completely.

In this activity, students investigate different methods (aeration and filtering) for removing pollutants from water. They will design and build their own water filters.

Students disassemble and analyze retractable pens. Through the process of "reverse engineering," they learn how the ink pens work.

With a simple demonstration activity, students are introduced to the concept of friction as a force that impedes motion when two surfaces are in contact. Then, in the Associated Activity (Sliding and Stuttering), they work in teams to use a spring scale to drag an object such as a ceramic coffee cup along a table top or the floor. The spring scale allows them to measure the frictional force that exists between the moving cup and the surface it slides on. By modifying the bottom surface of the cup, students can find out what kinds of surfaces generate more or less friction. They also discover that both static and kinetic friction are involved when an object initially at rest is caused to slide across a surface.

Students discover the mathematical constant phi, the golden ratio, through hands-on activities. They measure dimensions of "natural objects"—a star, a nautilus shell and human hand bones—and calculate ratios of the measured values, which are close to phi. Then students learn a basic definition of a mathematical sequence, specifically the Fibonacci sequence. By taking ratios of successive terms of the sequence, they find numbers close to phi. They solve a squares puzzle that creates an approximate Fibonacci spiral. Finally, the instructor demonstrates the rule of the Fibonacci sequence via a LEGO® MINDSTORMS® NXT robot equipped with a pen. The robot (already created as part of the companion activity, The Fibonacci Sequence & Robots) draws a Fibonacci spiral that is similar to the nautilus shape.

Students pass around and distort messages written on index cards to learn how we use signals from GPS occultations to study the atmosphere. The cards represent information sent from GPS satellites being distorted as they pass through different locations in the Earth's atmosphere and reach other satellites. Analyzing GPS occultations enables better global weather forecasting, storm tracking and climate change monitoring.

Through a teacher-led discussion, students realize that the food energy plants obtain comes from sunlight via the plant process of photosynthesis. They learn what photosynthesis is, at an age-appropriate level of detail and vocabulary, and then begin to question how we know that photosynthesis occurs, if we can't see it happening. Elodea is a common water plant that students can use to directly observe evidence of photosynthesis. When Elodea is placed in a glass beaker near a good light source, bubbles of oxygen will be released as products of photosynthesis. By counting the number of bubbles that rise to the surface in a five-minute period, students can compare the photosynthetic activity of Elodea in the presence of high and low light levels.

Students learn about the amazing adaptations of the ptarmigan to the alpine tundra. They focus one adaptation, the feathered feet of the ptarmigan, and ask whether the feathers serve to only keep the feet warm or to also provide the bird with floatation capability. They create model ptarmigan feet, with and without feathers, and test the hypothesis on the function of the feathers. Ultimately, students make a claim about whether the feathers provide floatation and support this claim with their testing evidence.