While Mordred's hovercraft runs on manure, the saucer is advanced technology. It has a green fuel rod that has been broken. You need to get a replacement fuel rod.
For the procedure, see the related question.
Setting the coordinates, you will find that none of the planets is in range. Go to the moon mentioned on Mordred's missing journal page, at X-56 Y-52.
you have to find the UFO in astro knights island.
x 56 y 52
you type 52,56 then you fly.
you use it to power the UFO on Astro Knights
in the mud use a flying device that runs on manuer to get there
The answer is the first dile is 56 the second dile is 52.
The saucer Excalibur is in the mud swamp to the right of the Mill. To reach it, you need the "hovercraft" (hover board) that is in the attic of the Mill. (To get it out, see the related question)
You have to replace its broken green fuel rod, and get some coordinates for its computer. The ones the queen gave you are too far away, so you will need closer ones. (see related questions)
The UFO has a broken fuel rod. Go to the dungeon and click on the robot. It will explode, leaving a new fuel rod. Click on Merlin and he will fetch the fuel rod for you.
Use the UFO. (The saucer Excalibur in the mud swamp past the mill.) To use it you need to find a fuel rod and the coordinates. Once you get to the Pewter Moon you can make a new spaceship. (see related questions)
you poot 56 52.
You put the green thing that looks like a glow-stick in the slot in the UFO, then you find the coordinates for Mordred, I can't remember where to find them, then you enter Mordred's coordinates and off you go!