This material was posted elsewhere in March 2006:
FANTASTIC VOYAGE - A Geometric Puzzle
The theme will be familiar but the puzzle is much harder than it looks. A space rocket is being prepared for launch. It cannot take off until the Senior Mission Engineer, that 's you, has made a copy of the view now seen from Mission Control. You must not remove your pen/pencil/felt-tip/biro from the paper and you must not trace any path more than once to complete your drawing. Here is a simple example:
Some key points have been numbered. Start with your pen on point 1 and then trace the figure by passing to the numbered points in this sequence: 2, 3, 5, 2, 4, 5, 6, 3, 1.
The whole image was traversed once only.
Are you ready to try? Did you manage it? No fibs! Did you fail?
You are welcome to come back and try again. Thank you for attempting FANTASTIC VOYAGE.