Science Today• Warm-up: Quiz on Wednesday, JANUARY 9th

• 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 CELESTIAL NAVIGATION

The action of finding one's The action of finding one's way by observing the sun, way by observing the sun,

moon, and stars.moon, and stars.

Who is Ptolemy (tol-uh-mee)?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 Solution3) Identify the Constraints

4) Design a Prototype

5) Evaluate the Prototype

6) Revise and Retest

TACOMA NARROWS BRIDGEhttp://www.youtube.com/watch?v=3mclp9QmCGs

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 functionalrequirements should be written so thatif they are satisfied, the problem itselfwill 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 thesolution.

• 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 developsomething that can be tested to see ifit satisfies the functional requirementsand constraints.

The Design Process - Example

Develop a test model/prototypeDoes 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 proposedsolution. 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 beimproved or what new trade-offs willhave 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 functionalrequirements and constraints.

Steps of the Design Process

1) Identify the Problem

2) Identify the Solution3) Identify the Constraints

4) Design a Prototype

5) Evaluate the Prototype

6) Revise and Retest

The Design Process Importance of Engineering

Safety

CHALLENGER SPACE SHUTTLEJanuary 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

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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.

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The Design Process Importance of Engineering

Safety

Roger Boisjoly Challenger Crew