SJ starting derelict scene

In the glorious scene when the engineer is firing up the telescope orrey thing before starting, we see that the mask is coming down to cover his head. That moment features the only scene when we actually can hear something from the engineer, he is taking a huge breath. We know these guys are no Sissies..I wonder what is happening there, is the mask just a pilot breathing device or may it be something more. [URL=http://www.imagebanana.com/view/h02ym9bg/sj.png][IMG]http://img7.imagebanana.com/img/h02ym9bg/thumb/sj.png[/IMG][/URL]