Ponies in space[working title]
"Hello Eon here, now since I know your familiar with the time frame around Nightmare Moon's return so I'm gonna explain everything that's happened in the last 7,000 years. So if you don't care for that stuff and want to jump in blind, skip to the next chapter (here)."
So anyway we start about 80-100 years after what you know when most of the elements have passed away. Twilight, while still sad over the lose of her friends, starts looking for a way to track down the next bearers of the elements of harmony. This research takes about 150 years, so we'll come back to this later.
Meanwhile technology is advancing at an incredible rate, all leading up to in 122 SERS (second era of the royal sisters) Equestria's first spacecraft launch, the changeling made Chrysalis 7, which made it into orbit and stayed there for 15 weeks. The space race further expanded to bigger and better goals for decades. The greatest craft developed in this time is the New Griffonstone, the first orbital space colony, launched 174 SERS. The colony stayed in orbit for 50 years before a civil war broke out, ending with the New Griffonstone self-destructing.
Also at this time Celestia started to go crazy unfairly imprisoning anypony suspected of rebellion, either longer than the law calls for or without a trial at all. Luna was against it but was to afraid to do anything yet. this is what will be known as Celestia I's first power trip.
So now we get back to Twilight in the year 236 SERS, when she created a way way to track down the new element bearers. Thus restoring the Council of Harmony