Captive of the Centaurianess by Poul Anderson

The flagship-spaceboat slanted into the moon's atmosphere with a whoop and a holler, blazed across the ragged surface, and lowered outside the great dome of Ganymede City. The clumsy hulks behind her wallowed after at a more leisurely pace.

Lacking spacesuits, the amazons were faced with a certain problem of entry. Dyann hovered over the spaceport and opened her disintegrators full blast. The port disappeared in a sudden tornado of boiling rock and leaping blue fires. When she had sunk a fifty-foot pit, she went down into it, hung before the side of it facing the city, and narrowed the dis-beam to a drill. In moments she had cut a tunnel through to the lower levels of the city.