When you're in need of a zero gravity environment, just slap on an anti-gravity patch and experience all the benefits of being in space without the lack of oxygen or solar radiation. At least, that's how it ought to work in theory.
Requiring a zero gravity environment to complete the Binary Diagnostic Link, Doc Greene slapped the anti-gravity patch on his back, and promptly began ricocheting around the laboratory out of control. Frankie naturally alerted the emergency services, and Heatwave was able to use a grapple to bring Doc Greene back down to the ground. Frankie pulled the patch off and threw it away, and it presumably ended up hovering around the ceiling someplace.