Science Today Warm-up: Quiz on Wednesday, JANUARY 9 th WRITE IN YOUR AGENDA You will get two warm-ups each day and you will be quizzed on them on Wednesday

Warm-Up # 1 – What is celestial Navigation? Warm-Up # 2 – Who is Ptolemy? Warm-Ups

CELESTIAL NAVIGATION The action of finding one's way by observing the sun, moon, and stars.

Who is Ptolemy (tol-uh-mee)? Ptolemy was a scientist. He was a mathematician, astronomer, geographer, and astrologer. He wrote a book in the year 150 (1862 years ago!) about the stars. Forty-eight Ptolemic constellations are still recognized today.

TODAY’s GOAL To recognize the steps of the design process. WHY? You will be designing a spacecraft to send to Mars BUT first let’s learn a little more about the process.

The Design Process Steps – page 5 in notebook 1) Identify the Problem 2) Identify the Solution 3) Identify the Constraints 4) Design a Prototype 5) Evaluate the Prototype 6) Revise and Retest

TACOMA NARROWS BRIDGE

1. IDENTIFY the Problem 1.Clearly identify the problem, identifying all aspects of the issue. It's not enough to identify the problem in broad terms.

The Design Process - An Example What is the problem? There is too much traffic near the school.

The Design Process - Example Is the problem specific enough? Identify the details. Are the cars traveling too fast? Are there too many cars? Are the cars poorly routed?

2. Identify the Solution Identify the functional requirements the solution must meet. What will make the situation better and work well? The functional requirements should be written so that if they are satisfied, the problem itself will also be satisfied.

The Design Process - Example What is the solution? What are the specific requirements? a) It must be easy to drop off and pick up students. b) Cars must arrive and depart within two minutes

3. Identify the constraints to the solution. What is a constraint? Constraint means to be restricted, Example: “Lack of money has been a major constraint on the building's design.

The Design Process - Example What are the constraints? Cars must follow the same route. Cars must stay 10 meters away from the building.

4. Design a Prototype The prototype is a simple model or a complete working model. The goal is to develop something that can be tested to see if it satisfies the functional requirements and constraints.

The Design Process - Example Develop a test model/prototype Does it work? You may draw a map on a piece of paper or you may draw yellow lines in chalk on the actual road.

5. Evaluate the Prototype Evaluate the prototype. In this step, the designer must test and evaluate his or her proposed solution. Note that this is more than simply asking, "Does it work?" In this step the designer must instead ask, "How well does it work?"

6. Revise and retest Revise and retest as needed. Based on the data collected in the previous step, the designer can see where the proposed design can be improved or what new trade-offs will have to be made. The engineer then goes back to step four (and sometimes back to step one!) and repeats the process until the design satisfies, as near as possible, all of the functional requirements and constraints.

Steps of the Design Process 1) Identify the Problem 2) Identify the Solution 3) Identify the Constraints 4) Design a Prototype 5) Evaluate the Prototype 6) Revise and Retest

The Design Process Importance of Engineering Safety CHALLENGER SPACE SHUTTLE January 28, 1986 First time for a civilian to go into space.

The Design Process Importance of Engineering Safety All seven astronauts aboard were killed within minutes of the launch.

The Design Process Importance of Engineering Safety 22

The Design Process Importance of Engineering Safety Why did it fail? - It was too cold. Specifically, an O-ring designed to keep rocket fuel from leaking, failed. The enormous forces created by the leaking fuel force the vehicle to tear apart. 23

The Design Process Importance of Engineering Safety Roger Boisjoly Challenger Crew