When I first saw this calendar sometime back in 1977, I'm sure my face fell in slack-jawed wonder. Some villain had knocked the moon out of its orbit, and only the Justice League (and Supergirl) could put it back in its rightful place! The concept is ludicrous, but the great Neal Adams somehow makes it work. Those kilometres-long harnesses bolted across the face of the moon are wonderful, and look at the strain on the faces of Superman and Supergirl. Adams totally sells it. Everyone has a role to play; presumably Green Lantern is either shoring up the harnesses so they don't snap, or helping push; possibly both. Wonder Woman is using her lasso to help arrest the Moon's fall, even though in this era she couldn't fly under her own power, so I'm not sure what's going on there. Compared to the titans putting all their godlike energy into the effort, Hawkman's Thanagarian police cruiser probably isn't adding much thrust to the package, but all for one and one for all. I suppose Aquaman, Green Arrow and Black Canary are on board to provide damage control if the ship blows some fuses.
As for Batman, well...thanks for coming out, Bruce, but standing there and yelling "Push! Harder!" can't be that helpful in this situation.