1. Environmental Control & Life Support Systems
Presentation designed April by Nikki Mertz, UAH GTA for Advanced Space Academy. Graphics added by Melissa Snider, USSRC, August 2001 from NASA online materials. Revised May, 2003: separated ECLSS from other systems, added Station ECLSS info & graphics. We are grateful for background information and consultation provided by Tim Reynolds of Johnson Space Center and Billy Gonterman, retired from MSFC.
Revised Dec 2005 by Nikki Mertz with info from Sarah Hubbard & Nathan Williams
Orbiter Information partially derived from NASA’s Human Spaceflight Website/Shuttle Reference and The Space Shuttle Operator’s Manual. Some material obtained from NSTS; other sources include the Shuttle Familiarization Manual (NASA Mission Operations Directorate,Space Flight Training & Facility Operations,Shuttle Systems Training Branch, December 2000) and Station Familiarization Manual (Mission Operations Directorate, Space Flight Training Division, July 31, 1998).
Revised May 2015 by Andrea Tribo for aesthetic clean-up, photo updating, and minor content changes/updates for use with Space Academy for Educators.
art credit: NASA &
ECLSS stands for Environmental Control and Life Support System. The systems on Space Station and the orbiter are very similar, although there are a few key differences related to technology improvements and the long duration of ISS flights.
On this picture of Space Station, the white area shows where most of the ECLSS hardware will be located when ISS is completed, just below the central portion of the truss (as of May, 2003, ECLSS functions are handled from the Russian Orbital Segment, which is toward the “rear” of this picture). On the orbiter, most of the hardware is located in Equipment Bay or in the forward section of the payload bay.
ECLSS
Environmental Control & Life Support Systems
USSRC Proprietary 2015

2. ECLSS PANELS Orbiter L1 & L2 ML31C
MEDS – Multi-function electronic Display System retrofitted to Atlantis 1999
ECLSS PANELS Orbiter
L1 & L2
ECLSS controls are on the commander’s side of flight deck, behind his or her left elbow on panels L1 & L2.
Additional controls related to the waste water flow are located on the middeck, above the ingress hatch.
Photo Credit NASA
ML31C

3. Explain what life support systems do on spacecraft.
Environment Control and Life Support Systems (ECLSS) on spacecraft, provide oxygen for breathing, remove carbon dioxide and impurities from the air, recycles water (including urine) for drinking water, food prep and hygiene.
True or False: ECLSS does not have anything to do with making the spacecraft fly, like propulsion.

4. Describe the Difference between open-loop and closed-loop systems.
The water recycling system on spacecraft is a closed loop. A closed-loop system is like the water cycle here on Earth. In a closed -loop system there is not an outside source of water; all water inside the spacecraft must be recycled.
Describe the difference between a closed-loop and an open-loop system.

5. Space Station Regenerative ECLSS Flow Diagram (Current)
Graphic credit: MSFC / NASA
Photo credit:
The job of the ECLSS system is to provide the crew with clean air at the right temperature, provide potable (drinkable) water, and dispose of any toxic waste products in a safe manner.
On the orbiter, on Space Station, or in a Soyuz emergency vehicle, the ECLSS-controlled space environment is very nearly a closed loop environment. The perfect long-duration spacecraft would be able to sustain itself without needing supplies or significant waste disposal for many years at a time.
Older Soviet spacesuits used to allow “used air” (CO2) to vent out to space, rather than clean it and reuse it. Shuttle astronauts reuse their air, but dump their waste water overboard. Space Station is moving toward reusing even waste water (although they do dump trash in the Progress). This kind of closed loop minimizes our impact on the environment of space, and minimizes the heavy supplies we must bring on board.
This Space Station ECLSS diagram gives you an idea of some of the specific duties of the ECLSS system and the subsystems used to complete those duties. Clean water is called “potable water.” Air cleanup involves Temperature control, humidity control and CO2 removal. Note that a few things are still dumped overboard (H2 and CO2), but they would have minimal impact in Low Earth Orbit.

6. Define efficiency.
The challenge is to build the most effective water filtration device. Very little water can be wasted on spacecraft; they need every drop. So, they must have very efficient filters to recycle the water. Efficient water filters are those that filter the water without absorbing any water. However, some absorption will be necessary to remove some contaminates and impurities.
Define efficiency.

7. Understand the design process.
Engineering Design is a cyclical process. It starts with an idea, then a prototype is built and tested, and then – based on testing - a new idea results for improving the prototype. The cycle continues until all the design criteria have been optimized.
Draw the design cycle.

8. Contribute as a team member.
Teams work best when each person has a role.
Recorder – writes group comments in the brainstorming section, recording what materials should be used and why. Also records group’s answers to questions on page.

9. Contribute as a team member.
Teams work best when each person has a role.
Purchasing Agent – The one person that purchases materials and keeps track of budget. This person is also the one primarily responsible for cleanup

10. Contribute as a team member.
Teams work best when each person has a role.
Designer – diagrams and labels the design on page 2 (a separate page may be used.

11. Contribute as a team member.
Teams work best when each person has a role.
Project Manager – keeps track of time, keeps everyone on task and presents the design to the class.
What did you do to contribute to making your groups water filter?

12. Become familiar with using the conductivity tester.
Conductivity is the physical property of a substance to conduct electricity. The conductivity of water will is a measure of impurities in the water. Pure water has low conductivity; it does not conduct electricity. Some conductivity meters report conductivity in terms of the amount of Total Dissolved Solids or TDS. The lower the number the more pure the water.
Would adding salt to water increase, decrease, or not affect the conductivity of the water?

13. Become familiar with pH
pH is a measure of how acidic or basic a substance is on a scale of 1 to 14. Pure water is “neutral” pH of 7. Rain water is slightly acidic 6.5 and human blood is slightly basic Battery acid is a 1 and Ammonia is 11
What is a neutral pH? 0, 1, 7, 11, 14

14. Become familiar with pH
All urine has ammonia in it. Ammonia is found in the waste of all living things. Ammonia chips are used is fish filters to remove ammonia from fish tanks, because too much ammonia in a fish tank can kill the fish.
Ammonia affects the pH of solutions.
True of false: Ammonia chips will increase the pH of water.

15. How Do You Go To The Bathroom In Space?
Video Credit: Chris Hadfield, CSA