The initial Idea
Part 1 My influences and some thoughts on what I would like to see
Part 2 A tentative skill list and a fleshing out of the die mechanic
Part 3 My thoughts on campaign frameworks that fit within the setting and system
That out of the way, here goes. My ideas for the setting of Trek to the Stars:
350 years in the future, after the world fell and the sky opened up again, we have moved beyond our small blue sphere and have taken our place in the heavens. Mars terraforming is nearing the end of phase two. Venus is going a different route. The game is set in the year 2365, and the frontiers of Man are limitless.
Mercury is split between two nations, several mining firms, the unions, and the independent miners trying to make a living.
Venus has a great many cities in the sky(as oxygen is a lifting gas there) they harvest the gene modded plants that float in, and live off, the vast cloud cover while dispersing vast amounts of ice into the planetary atmosphere. These shining cities drift on the winds and help deflect some of the solar rays that bombard the planet.
On and around Earth the old nation states still cling to their power and history, though many new nations have risen. This is the heart of the old Lords of the System(basically the aristocracy that has lost much power lately, but still holds more influence than some would like). This is a hotbed of politics and money, as well as extreme political leanings. With so many folk leaving the planet the populations have been lowered significantly.
Luna was once heavily populated, though now many folk have moved out to the new colonies and wide open spaces. Now it sits as backwater and historical site. Like a ghost town, but in space.
Mars has enough atmosphere that folks can breath unaided, and there are even some rivers and lakes. It is separated into three(or more, haven't decided yet) nations. There was a recent civil war has concluded over the southern portions of the planet, They seceded from, and were retaken by, a large neo-fascist regime. Their luxuries and education are currently being taxed punitively by their fascist overlords.
Ceres exists as the trade hub of much of the asteroid belt. Anything can be bought and traded here. It stands neutral in the dealings of the solar system at large. A great many asteroids have been moved near it so that miners can trade easier.
Europa has vast cities hanging from the ice down into the unlit depths. They have little to do with the outside system, the only access to their undersea realm is two surface stations over great elevators to the subsurface populations. The remaining Jovian moons are also heavily colonized, though I still haven't worked out how it is all arranged.
The moons of Saturn are home to a pseudo-feudal society that controlled most trade of He^3 throughout the system. They are a rich and jealous of others power. They live lives of glorified violence as one of the only ways to advance beyond the serf/peasant/worker caste is to join the local military and distinguish yourself. Distinguished soldiers can be adopted into the ruling families. Military might and economic power are all that matter on the grand scheme. Each lord serves a higher lord and so on. All fall under the domain of the Saturn Emperor.
The independents around Uranus have begun to cut into the Saturn Baronies profits with their cheaper and easier to extract He^3. They are a disorganized and unruly bunch. Libertarian ideals founded the colonies, but soon thereafter the society almost collapsed and so a slightly stronger government was constructed, but the people are still independent and free wheeling.
Out beyond this lies the great frontier. The moons of Neptune, Pluto, the Kuiper belt, and Eris are all somewhat colonized. Many hermits, tribes, bands, micro-nations, and families have moved out to the region with nothing but a fusion plant, a ship, and a fabricator. Live is hard, but riches can be had with a bit of work and a bit of luck.
Major Important Technologies
Fusion Reactors: Invented in the mid twenty-first century its proliferation changed everything. Requires He^3 or Deuterium as fuel, depending on the model of reactor. A small one can power a habitat large enough for six for years with little complex maintenance.
Fabricators: A large machine that uses robotics and micro-robotics to construct anything it has the plans for. You must put the required material in the required amounts into the hopper. No household should be without one. You must purchase fabrication rights for the plans of any item you wish to construct and raw materials needed. Pirated plans and hacked fabricators are difficult to obtain, but not impossible. Laws regarding rights usage often change depending on which country you are in and from which the plans come. Basically advanced versions of 3D Printers.
Solar Sails: The cheep method of traveling (relatively)swiftly throughout the system. Solar sails are the preferred method for most colonists.
Ion Thruster: Using argon this engine provides steady thrust at a low cost. I am unsure if there isn't a better drive than this one, I do love the name of it though.
Mass Driver: An electromagnetic accelerator used to transport goods from ground to orbit. Used on Mercury, Luna, and several of the moons of the gas giants.
Alcubierre Shunt: A device like a beacon that allows a ship to travel faster than light for short periods. It bends space into a warp bubble around your ship and then fires that bubble of in a direction. In order to end the effect you must strike another beacon. Travel can take anywhere from a week(Earth to Venus) to a month and a half(Earth to Neptune)
Space Elevators: Mars and Titan have the only currently operational space elevators in the system. Though Earth has been working on constructing one for the last two years.
Vacuum Balloon: Recently materials science has advanced enough that this has become a possibility. Now there are several Vacuum Airships patrolling the skies of Venus. And recently a few such airships have been sent to Jupiter as a proof of concept toward building permanent cities in Jupiter's upper atmosphere.