From publisher blurb:
Multitudes of worlds wheel through Wildspace. The crystal shells that encase them bob and drift in a turbulent, rainbow ocean which fills all the cosmos. Sturdy merchants, bold pirates, and daring explorers venture into the great, unknown vastness of the universe, seeking wealth and adventure.
The SPELLJAMMER Game puts you in command of a fantastic ship capable of spanning the tremendous distances between planets. Graceful elven flitters, stately illithid galleys, deadly beholder tyrants, and the awesome Spelljammer itself carry trade, emissaries, and heroic action throughout all the worlds of the AD&D game.