Space Sword Blaster was an offensive attack used by Sailor Uranus.
When this attack was used in the anime or the video games, the Space Sword's blade would glow, and she would then swing the Sword and release a wave of energy that would destroy its target. In episode 169, it was demonstrated that this attack could also hit multiple enemies simultaneously.
When it was used in the manga, the blade would grow larger and glow, and she would then use the Sword to physically attack her enemy.
Sailor Uranus used this move in Sailor Moon SuperS: Zenin Sanka!! Shuyaku Soudatsusen. Sailor Uranus made a slash in the air with the sword and sent a wave of energy at the target.
This is, also, one of her two attacks in Sailor Moon: Another Story (the other being World Shaking ). She swings her sword, releasing a flash of energy that damages the target. It hits one enemy at a time and consumes 4 EP.