What is a ssc file ? It's a file holding the main informations for one ore more Celestia objects. It include the satellites' names, planets, gravitational datas, etc. It can be edited with notepad, and if you want to progress with Celestia, you'll have to understand how to edit it.

It is meant to be placed in "data" directory (check the main Celestia directory), or still better, at the root directory specialy made in the "extra" directory. To have a look of how it does work, check tips.