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Trash or Treasure
Investigation: What are the important characteristics of a successful ecosystem?

In a completely balanced ecosystem, there is no waste. Balanced ecosystems naturally recycle biological waste. In fact, in a balanced ecosystem nothing is waste. Material that is waste to one organism is food for another.
Image of a recycle symbol over a picture of Earth, the moon and Mars

Innovative recycling methods will grow in importance for our own communities, as well as future space habitats on the moon and Mars. Image Credit: NASA

On Earth, many things can cause an imbalance in the ecosystem. For example, over population can unbalance an ecosystem, and waste can build up. Populated areas need more effective waste treatment systems. Organic waste and discarded manufactured items threaten to overwhelm landfills. Some materials in landfills take thousands of years to break down. Recycling efforts have reduced the amount of waste going into landfills. Recycling can save money and reduce the energy needed to produce new products.

The closed environments necessary for space exploration will create extra challenges. It will be necessary to recycle organic waste, possibly to produce nutrients for plants. For packaging on the space shuttle and the International Space Station to be kept to a minimum, new technologies are being developed that will allow packaging to be broken down into nutrients for plants or changed into building materials.

Students learn about recycling in their own communities and apply their knowledge to space habitats.

Assessment Task:
Students will design a system to recycle matter in a habitat for researchers on the moon or Mars and explain why it should be successful.
Download Formative Assessment Rubric (PDF)

Content Area Resources
The following Web resources are provided to assist you in facilitating inquiry-based learning and to address the investigative questions for this unit. Choose the resources that work best in your classroom. Some of the resources are on NASA Web sites and others are not. Web sites that are external to NASA are indicated with an arrow. Some items may be in PDF format. Recommended grade levels are indicated whenever they are specified in the educational resource.

Reducing Waste and Recycling
Environmental Protection Agency Curriculum and Activities (Teacher Resource) (K-6, 6-8 and 9-12)  →
EPA Teaching Resources -- Waste and Recycling (Teacher Resource) (K-6, 6-8 and 9-12)  →
Welcome to Recycle City Web Site (6-8)  →

Ways to Handle Waste in Space
These articles describe ways to handle waste in space.
Not Your Backyard Compost Heap (9-12)
Recycling for Moon, Mars and Beyond (K-4)
Plumbing the Space Station (10-12) (Audio version available on Web site.)  →