Batman can breathe in space
With space faring Justice League teammates, it only makes sense that Batman ends up fighting in outer space once in a while. Unfortunately, the honest truth is that without powers, he is probably even less useful in space than Aquaman is on land.
However, his popularity lends to some hefty suspension of disbelief, and/or poor fact checking. Thus we get toys with Space Batman without a fully functioning space helmet leading to the highly influential web comic above. It led to an eponymous tv trope and came full circle in the pages of Superman/Batman when Batman gained the powers of Superman and this writer tipped their hat with this panel.
ps. Batman has been shown training himself how to best survive deep space for a few moments. Of course he has.










