Technological Design
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
STS-118 Design Challenge
Lunar Plant Growth Chamber
Teacher Resource 3.2
STS-118 Unit: Big IdeaSTS-118 Unit: Big Idea
The Engineering Design Process is a comprehensive, valuable tool that can be used to provide solutions to complex challenges on Earth and
beyond.
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
Lesson 3: Big IdeaLesson 3: Big Idea
The design of technological devices requires the consideration of
limitations, trade-offs, and many iterations before a final design can
be selected.
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
Identify Criteria and Identify Criteria and ConstraintsConstraints
• Helps to specify subsystems• Affects final design and development• Subsystems include:
• Water and nutrients• Air circulation• Heating and cooling• Lighting• Radiation protection
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
Active SubsystemsActive Subsystems
• Are mechanical/electrical devices needed?• Pumps• Fans• Lights• Heaters• Recorders
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
Energy SourcesEnergy Sources
• Power needed for active subsystems• Batteries• Photovoltaic cells• Radioisotopic thermoelectric generators• Fuel cells
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
ControlsControls
• Feedback devices• Sensors• Timers
• Brains• Microprocessors
• Switches• Example: window fan with thermostat
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
Passive SubsystemsPassive Subsystems
• Feedback devices not required• Example, air moving by convection
currents in a gravity environment
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
OptimizationOptimization
• Ongoing process of designing• Dependent on criteria and constraints• May require subsystem redesign• Models and prototypes allow testing for
quality and efficiency
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
System StabilitySystem Stability
• Influenced by all components in the system
• Complex systems have many layers of controls and feedback loops• Results in more ways things can go wrong• Components detect, back up, bypass,
compensate for minor failures
• Example: Three fuel sensors in the space shuttle external tank
© 2013 International Technology and Engineering Educators Association STEMCenter for Teaching and Learning™ Technological Design
