English: How does the Environmental Control and Life Support System work on board the orbiter? The Environmental Control and Life Support System on board the orbiter, or ECLSS as it’s known,is how we provide a normal atmosphere to the astronauts while their up in space.Now when they’re up in space we have to replicate all the stuff that we have here on the ground. We have to give them breathable air, we got to get the Carbon Dioxide out of the air, remove the humidity,and it’s a very, very complex system that does that.We also want to give the astronaut approximately what they’re breathing here on the earth which is about 20% oxygen and 80% nitrogen. We also have tools which remove carbon dioxide from the air.One of these is called the Lithium Hydroxide or LiO canisters that we have to carry a bunch of up there with us.We also have to get the humidity out of the air.And we have a humidity separator located there inside the orbiter’s crew module that gets all that humidity out and allows them to have a nice comfortable short sleeve atmosphere. One of the other things that we need is water. And what you may not know is the water we get for the astronauts to get drink actually comes from the devise called fuel cells that provide the electricity for the orbiter when it is flying around. Another aspect of the Environmental Control and Life Support System is we have to get rid of human waste. We do have a toilet onboard the orbiter that allows the astronauts to do everything up in space just like they do it here down here on earth. And that’s our Environmental Control and Life Support System.