On the scorching, lava-filled world of Mustafar, Sith apprentice Darth Vader fell prey to merciless fire that burned and destroyed most of his human body. It took the most advanced technology and medicine available in the Star Wars universe — and maybe a little Sith dark side energy — to keep him alive after barely surviving.
The black and machine-like suit and helmet Darth Vader wears are actually his life-support system, created to artificially sustain his existence far beyond what should have been possible. His mask, which helps him breathe, was perhaps the most essential piece of this intricate biotechnological miracle.
But we do see him several times with part of his mask broken in Star Wars — and he survives both of those instances. So what does Darth Vader’s mask actually do, and how does it keep him alive?
How Darth Vader’s mask helps him to breathe
In both Star Wars Rebels and the Obi-Wan Kenobi series, different sides of Vader’s mask break during lightsaber battles. In Rebels, Vader finds himself face-to-face with his former apprentice Ahsoka Tano. One of his eyes becomes visible when his mask breaks, but he’s still able to breathe. And in Kenobi, Vader’s former master also breaks one side of the mask. Even though it impacts the way Vader speaks while the mask is broken, it doesn’t negatively affect his breathing.
This may be because there’s a specific breathing apparatus in the mask, but breaking either side of the mask wouldn’t necessarily wreck that system permanently. Darth Vader’s mask is attached to an air pump, which itself is attached to a filtration system on his back (it sort of looks like a backpack). This apparatus is what filters breathable air through his lungs, which are too damaged to do the work themselves.
When Luke tells his father at the end of Return of the Jedi that Vader will die without his mask, he’s right. The only time we see Vader with his entire helmet off is when he’s in his bacta meditation chamber (where he looks like he’s floating in water in a tank). In these instances, he’s still using assistance to breathe. If he were to stand in open air without the help of his mask, he would stop breathing.
And that’s what happens at the end of Episode VI. Knowing he’s going to die anyway, Darth Vader instructs Luke to remove his mask for him so he can look at his son with his own eyes — for the first, and the final, time.
Perhaps Vader could have survived with immediate medical intervention if he’d kept his mask on and Luke had been able to get him to safety. But the removal of his mask basically sealed the deal. Without artificial breathing assistance, Vader never would have survived as long as he did. In a way, Vader refusing to let a machine sustain his life was his final act of renouncing who he had become. No longer Vader, but once again Anakin Skywalker, he was able to reclaim his former self once and for all.