Let's take a second look at the Ascension loading screen...

[Nemesis_96]

Dudes, they are Soyuz-2 rockets, as said by Woods in Executive Order. It's fairly clear these are indeed the same rockets from the campaign and the MP map Launch. Here's a pic of the real Soyuz-2's:

Looking up "Soyuz-2 blueprints", I think I found the image Treyarch used in game!

[die Doktor]

Things seem almost reversed.

The rockets on the Ascension screen are smaller, they look to be based off V2 rockets. Those rockets aren't getting anywhere out of the atmosphere. The rockets on Moon, however, are much bigger, like soyuz rockets. The catch about the moon is that you do not need as much power to get away from it's gravity, where on earth you need 17,500 MPH to escape orbit. You would think the larger rockets would be on earth, and smaller ones on the moon. Puzzling stuff.

Possibly, the rockets on Moon could be larger to add an extra Kinetic strike,think End War, before detonation burrowing into the ground. No real reason for small rockets on Ascension. Maybe beginning of space race and is for testing.