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. 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.

4. ECLSS: Air Earth Pressurization System - supplies breathable air
A. Earth’s Atmosphere
1. ~79% Nitrogen
2. ~21% Oxygen
3. < 1% Trace Elements
psi
Ask the kids if they know these values before you display them

5. ECLSS: Air Orbiter Only
I. Pressurization System (cont)
B. Orbiter Components
80% Nitrogen (11.2 psi*)
20% Oxygen (3.5 psi*)
*partial pressures do not correspond to percentages
4. Pressure varies:
14.7 nominal
16.7 cabin leak check
10.2 before EVA
The trace elements are not needed to live and work in space so we only bring up oxygen and nitrogen.
The pressure is 14.7 psi initially then the crew cabin’s atmosphere is brought down to 10.2 psi twelve hours before EVA to make it easier for the mission spec. to depressurize before their EVA.
-oxygen is brought up in liquid form to save space – it is kept at -280F and a freon coolant system warms it up before it enters the cabin – when it does enter the cabin it is at 3.5 psi
-nitrogen is brought up in a gaseous form – when it enters the crew cabin it is at 11.2 psi
-there are regulators on board, similar to SCUBA regulators, that control the actual pressure of the air inside the crew cabin – oxygen and nitrogen are at a very high pressure initially and the regulator is what brings them down to their correct psi for the crew cabin - the orbiter has relief valves that would open in case the regulator failed – there is also an emergency regulator that reduces the pressure to 8 psi in an emergency
N2 & O2 stored midfuselage

6. ECLSS Air Station Only I. Pressurization System (cont.)
D. Station Components
80% N2, 20% O2
Pressure 14.7 psi
E. Station Supply
N2 & O2 tanks: Progress
O2 source: electrolysis
Backup O2: solid cartridges (exothermic)
                                             
Oxygen
Hydrogen
The Russian Orbital Segment (ROS) had primary responsibility for atmosphere control and supply functions until Destiny was added (2003). The Russian Zvezda module initially provided oxygen via electrolysis. The U.S. modules supplemented that system.
The Progress resupply vehicle is outfitted with tanks that can be filled with either nitrogen, air, or oxygen. These tanks are manually opened by the crew if the cabin pressure is low.
From International Space Station Familiarization Manual - Current - The Elektron system aboard Zvezda and a similar system in Destiny generate oxygen aboard the station through electrolyzing water into hydrogen and oxygen . The crew has a backup option in the form of bottled oxygen and Solid Fuel Oxygen Generation  (SFOG) canisters.[
(Note that if the backup oxygen generator is used, then the cooling system would work harder) – Melissa
There is an air compressor inside the airlock which allowed Shuttle to refill O2 storage tanks, because Shuttle stores O2 at a lower pressure than ISS
Electrolysis Graphic: News-StationAir.asp

7. ECLSS: Air Orbiter Only
II. Air Revitalization System (ARS) – cleans used air A. ARS Microfilters -traps dust, hair, skin cells, etc… B. LiOH canisters-removes carbon dioxide C. ATCO (Ambient Temperature Catalytic Oxidizer) - turns CO into CO2
a) Filters - they trap dust, hair, skin cells, etc. – fans draw air through the system
-Mosquito story – NASA insists on keeping the Orbiters clean and free of outside invaders – one time after an Endeavour mission the clean-up crew found a mosquito trapped in the filter – they gave it a funeral to mark the occasion
Trainees should be able to tell the difference between a dirty and a clean filter
 b) LiOH canisters
-remove CO2 from the air
-absorbs CO2 and turns it into solid lithium carbonate – this fills up the container and it must be changed-one canister can last 24 hours for 4 people – however, there are usually 7 people on board an orbiter so they change it every 8-12 hours
-when the LiOH canister gets full it won’t remove the CO2 and this can cause brain asphyxiation in the astronauts – the first symptom is confusion but if it is not treated it can be deadly
-Columbia hds a regenerative system on board – LiOH system is only there as a backup
 c) ATCO (Ambient Temp. Catalytic Oxidizer)
-turns CO(carbon monoxide) produced by equipment in CO2 so the LiOH system can remove it
Station is initially used LiOH canisters but now uses other systems.
LiOH
Canisters

8. ECLSS Air Station Only
Air Revitalization System (ARS) – cleans used air
A. Gas Analyzers: check levels of O2, toxic gases; O2 added automatically as needed
B. CDRA – Carbon Dioxide Removal Assembly - rechargeable CO2 removers
Photo Credit: NASA
Trainees should be concerned with leaks as a possible thinking anomaly on the station
Major Constituent Monitoring
The Major Constituent Analyzer is a magnetic-sector mass spectrometer. It has 6 simultaneous detection channels – monitors hydrogen, methane, oxygen, nitrogen, water and carbon dioxide - monitors the composition of the Station atmosphere by mass spectrometry. Measurements are used to control the addition of oxygen and indirectly, nitrogen, into the Station atmosphere by the Atmosphere Control and Supply Subsystem, and to monitor the performance of the assembly that removes carbon dioxide.
Present: In the ROS, the Gas Analyzers use several different gas detection methods to provide similar functions.
Carbon Dioxide Removal
The Carbon Dioxide Removal Assembly (CDRA) collects carbon dioxide from the cabin atmosphere with a series of regenerable sorbent beds and expels the unwanted gases to space. To remove carbon dioxide effectively, the CDRA requires cold, dry air, so it receives air from the Temperature and Humidity Control Subsystem and interfaces directly with the Internal Thermal Control System Low Temperature Loop. On the ROS, the Vozdukh performs the same function as the CDRA. Lithium hydroxide-based canisters are available for backup ROS functionality.

9. ECLSS Air Station Only
Air Revitalization System (ARS) – cleans used air
C. Trace Contaminant Control Subassembly – filters gas contaminants with charcoal
D. Harmful Impurities Filter – backs up TCCS
Photo Credit:
Trace Contaminant Control
The Trace Contaminant Control Subassembly filters and catalyzes numerous gaseous contaminants and odors from the cabin atmosphere. These contaminants are caused by material off-gassing, leaks, spills, or other events. On the ROS, the Trace Contaminant Control Unit operates similarly to the Trace Contaminant Control Subassembly. The Harmful Impurities Filter provides backup contaminant control as needed.
Additional Atmosphere Revitalization Capabilities at Assembly
Complete
At Assembly Complete, the USOS adds duplicates of each of the Major Constituent Analyzer, Carbon Dioxide Removal Assembly (CDRA), and Trace Contaminant Control Subassembly. These duplicates will serve as backup only, because each device operates at a three-person rate. The ROS has similar capabilities which will be used in conjunction with the USOS equipment, and together they will be sufficient to support a six-member crew.

10. ECLSS: Air Orbiter/Station
II. Air Revitalization System (cont) D. Heat Exchanger
-Nominal temperature:65-80°F
-Nominal humidity: %
-Cabin air passes or bypasses heat exchanger
-Station temp, humidity more consistent & homogeneous than orbiter
Trainees should consider what might happen if the humidity got too high

11. ECLSS: Water Orbiter Only
III. Supply and Waste Water – Panel ML31C A. Fuel Cells -produce water as a by-product of electricity -purge for peak performance B. 5 tanks: 75 gallons total A – drinking water B,C,D – cooling system E – waste water
5 tanks
#1 – drinking water – 0.5 ppm iodine added
#2 - #4 – used for the cooling system
#5 – waste water – must be dumped on the light side – tell the peesicle story if they haven’t already heard it
-the water is routed to the tanks through a microbiotic filter – it goes to Tank #1, then #2 and so on
Tell trainees that they will have to rely on mission control to tell them when they are on the dark side or the sunny side before dumping the tank

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

13. ECLSS: Water Station Only
III. Supply and Waste Water A. Finite supply brought via Progress or Shuttle
B. May 2009: total recycling via Boeing’s Water Recovery and
Management Subsystem
Astronauts aboard station have a finite supply of water. The eventual goal is for them to have a closed loop – that is, they will recycle every possible drop of moisture. A water filtration system designed by Boeing has been produced that recycles water that is 99% pure –meeting or exceeding the requirements of municipal water sources on Earth. Water flowing into your kitchen sink from a water treatment plant is typically only 94% pure. ISS crew of Expedition 19 got a Go to drink the first recycled water on May 20, This helped make the jump from a 3 person to a 6 person crew possible.
About 93% of all water is reclaimed and recycled. About 6000 L of water is recycled each year.

14. ECLSS Review ECLSS regulates 3 things: Air - pressure & revitalization
Temperature
Water – supply & waste
Nominal air components:
N2 – 80% (11.2 psi)
O2 – 20 % (3.5 psi)
Nominal Temp & Humidity:
65-80 F, 35-60%

15. Can you convert the Astronaut urine into clean drinking water?
ECLSS
Environmental Control & Life Support Systems
Challenge
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.
Can you convert the Astronaut urine into clean drinking water?
You have a budget of 1200 credits – plan your spending wisely.
We will be marking your success on the pH of the water, the Clairty (colour) and the efficiency (don’t lose any water!).