NASA Life Support


  • Weighting Systems
  • Factors

MEA Description: This activity requires students to create a procedure for analyzing life support systems in order to determine which system is best for use in space. The teams are given a set of data for five systems that experts from NASA have already ranked from best to worst. Team must use this data to develop a mathematical procedure that uses the data given to rank these five systems. When the teams’ procedures are applied to the NASA ranked data, the systems should be ranked in the same order. The students are then asked to apply their procedure to a new set of specifications for life support systems in order to rank them from best to worst.

Implementation Strategy:

  1. Individual Activity � Students individually begin to articulate what factors go into the selection of a subsystem. The focus is at developing a list of things that a real NASA engineer must take into consideration when selecting a system for a mission.
  2. Team Activity � In teams of four, students read the interoffice memo from the NASA researcher which establishes the need to create a procedure to more consistantly analyze subsystems based on their properties. They are given a sample data set and a list of "expert" ranking.

Six Principles:

Principle Description How the principle is addressed in the MEA?
Model Construction Ensures the activity requires the construction of an explicit description, explanation, or procedure for a mathematically significant situation
Describe the mathematical model the students will be developing when solving this MEA:
  • What are the elements?
  • What are the relationships among elements?
  • What are the operations that describe how the elements interact?
Elements – characteristics (power, mass, volume, crew time) and subsystems
Operators – add/subtract/weigh factors
Relationships – rank subsystems
Reality Requires the activity to be posed in a realistic engineering context and be designed so that the students can interpret the activity meaningfully from their different levels of mathematical ability and general knowledge
Describe the context. What is the story?
What knowledge will students need to bring to this problem?
What background information must be provided?

Describe how the problem is open-ended.
NASA subsystems
Different factors for consideration in systems
Self-Assessment Ensures that the activity contains criteria the students can identify and use to test and revise their current ways of thinking
What is provided in this MEA that students can use to test their ways of thinking?
Using their procedure on the sample cases to rank 3 subsystems.
Model-Documentation Ensures that the students are required to create some form of documentation that will reveal explicitly how they are thinking about the problem situation
What documentation are the students being asked to produce in this MEA?
Memo and procedure
Construct Share-Ability and Re-Usability Requires students produce solutions that are shareable with others and modifiable for other engineering situations
What will indicate to the students that a sharable, reusable, or generalizable solution is desired?
Sharable – produce procedure that NASA can use.
Generalizable – Should be able to use for other cases
Effective Prototype Ensures that the solution generated must provide a useful prototype, a metaphor, for interpreting other situations
What are other examples of structurally or conceptually similar problems that would required a similar solution?
Models for ranking systems

Author Information:

  • Original Author(s):
    • Euridice Oware
  • Assisted by:
    • Tamara Moore
    • Carla Gerberry
    • Irene Mena
    • Matthew A. Verleger
  • Special Thanks:
    • Julia Hains-Allen
      Outreach Manager
      ALS/NSCORT Center
      Purdue University


Written Spring 2005 Tested in ENGR106 - Fall 2005