Darth Vader já foi exposto ao vácuo do espaço?

Sim

Eu lembro que isso aconteceu pelo menos uma vez na série de quadrinhos de Darth Vader da Marvel, mas é mais conveniente para mim citar o romance canônico Lords of the Sith :

Vader hit a switch and depressurized the interceptor's cockpit, his armor shielding him from the vacuum. Then, as he neared the transport's midline, still swinging his ship left and right to dodge the incoming fire, he selected a spot on the transport adjacent to the gun bubble and, using the Force, took a firm mental hold on it.

His interceptor streaked toward the gun bubble, aimed directly at it. Content with the trajectory, he unstrapped himself, overrode the interceptor's safeties, threw open the cockpit hatch, and ejected into space.

Immediately he was spinning in the zero-g, the ship and stars alternating positions with rapidity. Yet he kept his mental hold on the air-lock handle, and his armor, sealed and pressurized, sustained him in the vacuum. The respirator was loud in his ears.

^{Lords of the Sith Chapter 1}

Acredito que os caças TIE não sejam navios pressurizados (de acordo com a história manual do jogo TIE), o que significa que enquanto Vader estava pilotando um TIE durante a cena da Batalha da Estrela da Morte no episódio 4, seu traje serviria propósito e protegê-lo do vácuo.

Sim. No filme:

Rogue One

É difícil dizer o que essa tag spoiler estraga, sem fazer o spoiler. Mas, bem, você provavelmente pode adivinhar o que vou dizer.

At the end of Rogue One, just after the Death Star plans have been narrowly evacuated from the Alliance cruiser, Vader stands over the docking port and stares into space where the escape pod / shuttle once stood.

Interestingly, his black-clad troopers are there with him, so their gear appears to be equally protective against the vacuum of space.

Sim. Além das respostas anteriores, isso aconteceu com Darth Vader também em uma revista em quadrinhos Legends da Marvel, Para levar o Tarkin . Aqui, um grupo de oficiais imperiais conspiram e tentam assassinar o Lorde Sith. Eles remotamente abrem uma porta de ar atrás dele e a atmosfera do corredor de despressurização o empurra para fora do navio. Apenas com o poder do Lado Negro, Vader é capaz de se retirar do espaço.

Enquanto isso é tecnicamente conceitos de pré-produção para o primeiro filme Star Wars (1977), uma explicação é fornecida em este artigo no site oficial de Star Wars para uma das imagens mais conhecidas criadas pelo artista / designer conceptual de Star Wars Ralph McQuarrie Fevereiro de 1975; veja a imagem abaixo.

E FWIW, parece que essa pintura conceitual finalmente ganhou vida em 2016, considerando…

…Darth Vader massacres Rebel troops in the airlock of a Rebel ship at the end of Rogue One (2016). While that airlock may—or may not—still be pressurized, the similarities between that scene in 2016 and Ralph McQuarrie’s illustration in 1975 are too strong to dismiss.

“Perhaps the most popular of Ralph’s paintings to appear in the portfolio, the laser duel, as he referred to it, was completed in February of 1975. While the portfolio, and nearly everyone who has discussed this painting in the past 35 years, describes it as ‘Luke versus Vader,’ at the time it was painted, the protagonist would have been Deak Starkiller from the second draft screenplay Ralph was working from.

It was because of this scene that Darth Vader came to have the look that he does. Ralph, concerned that Vader was jumping from ship to ship through the vacuum of space, felt that he would require some sort of breathing apparatus. George agreed, and the look of the masked villain was born.”