http://img.photobucket.com/albums/v157/_Duke_/2012-02-17.jpg
I didn't do anything weird or complicated, just walked out into space.
I only knew to do it because some treasure from an enemy fell out there; followed the trail of bread crumbs...
Edit: If the gate matters, it was Dark King gate (the newest gate). Depth 7, as seen in the photo.
It's been reported before.
http://forums.spiralknights.com/en/node/42143