Dear Elchristou:
I'm delighted to advise you that your request has been fulfilled. Not only does Celestia have the How-to-manual available, but it has an extensive set of lessons on what lies up there in space. The lessons are named the Celestia Educational Activities, and are available on the Motherlode at:
http://www.celestiamotherlode.net/educational.html
There are nine separate lessons with two more on the way. They are written in simple language for a 7th to 12th grade audience and take you on a detailed series of journeys through Celestia space. Along the way, they explain astronomical facts in great detail. You get to visit all the planets, moons and spacecraft in the Solar System and learn about them in detail. There are video movies imbedded in the Activities. There are hundreds of locations that they take you to in Celestia's world of space. You can visit Sputnik on the day it was launched, or a rotating Black Hole around an exploded Supernova. You can accompany the Cassini spacecraft to Saturn and ride down to the surface of Titan with Huygens.
The Activities will take you forward in time, and backward in history. Meet Voyager 2 as it sails beyond the orbit of Pluto. Accompany Neal Armstrong in 1969 as he orbits the moon in Apollo 11. Travel to the 26th century to watch humans terraform the planet Mars into a green, livable world. Drop by the Orion Nebula to watch new stars being born. You can even travel forward to the far future to witness our sun swelling to a Red Giant.
Although they come in separate units, the Activities collectively add up in length to that of a small book (over 200 pages), and are so extensive that it will take you over 18 hours to take all of their journeys.
They tour the universe, the Solar System, the spacecraft of humans, the complete life cycle of stars, and several other great topics. To date, over 100,000 people have downloaded one or more of them from either the Motherlode, or from my website. All documents and add-ons needed for the activities are included in their download zip files.
Click on the "sticky" that discusses them. You can find it at the top of this forum section.
Visit the Motherlode website and begin the journey that you seek.
Enjoy with my compliments.
Regards,
Frank Gregorio