Kiteretsu Daihyakka

Kiteretsu Daihyakka (キテレツ大百科), aka Kiteretsu Encyclopedia, contains a lengthy spacewalk scene in episode 3, where Kite is first thrown out by accident, landing safely to the Moon a while after that, despite his rocket experiencing a far opposite fate. He then finds out he's running out of air in his oxygen tanks, and after a couple sayonaras to his friends, he lays down thinking there's no chance of survival anyone, until... Oh well, we'll let you see it for yourself.