First, a definition of what a feelie is:
"Feelie" is a term first used by Infocom to refer to the extra content included with the boxed versions of their interactive fiction computer games. Feelies differed from game to game and were of the same theme as the game they came packaged with. For example, Wishbringer, a fantasy game with magic, came with a "Magick glowing stone." These extra objects and documents sometimes served as a form of copy protection, as several games were impossible to solve without information found in their feelies. Although the term was first used by Infocom, it can refer to similar content found in any company's games. — Feelie, Wikipedia
In the context of a pen and paper game, a feelie would be any physical object you create that draws the players into the world of the PCs. This could mean making physical keys, weapons, government paperwork forms, currency, etc. that mirrors the world the PCs inhabit. Feelies can be used to effectively communicate themes, subtext, or backstory through a direct, memorable object. That pilot's license application? Filled with obscure and unanswerable questions that make a real world tax application look simple, can communicate a lot about the government the players are interacting with through their PCs. Likewise, the signature weapon of a dead NPC ally bequeathed to a player, or pamphlets given to them as they walk through a space port can also used to communicate about the world (and insert plot hooks!).
2) In media res
In general, in media res simply means starting in the middle of the action. This is used all the time, and most often by action stories (particularly movies) to get the adrenaline pumping and set the stakes immediately. Beyond this application, in media res can also be used to put the characters immediately into the story in a situation that is both exciting and communicates a lot of what they need to know about the setting and the type of campaign they will be played in. For example, characters starting their adventure under-fire from gov't licensed space privateers while they deliver medical supplies to a backwater world (under the control of a different gov't) can communicate a lot. Likewise, how you, as the GM, present possible solutions (or let them create their own) will inform them about the world.
3) Reward good roleplay/world knowledge
Whenever Players have their PCs backup their approach/tactic/argument with actual setting appropriate knowledge give them a bonus toward success and/or a bigger reward.
Create a great Opening action scene (which could even be a tense, trade negotiation, given its Traveler) highlighting 2 different factions, 1 key aspect of the world, and 1 or 2 themes of the story you will be creating. This will in no way tell them everything they need to know, but it just might pique their interest to actually read the materials you've provided for backstory. Create 1 or 2 appropriate feelies that can be passed around and looked at by players to further draw them in. After their initial introduction to the the world through their in media res starting adventure, take off the kid gloves and have their lack of world knowledge backfire on them (when appropriate). When they end up running from Johnny Law because they broke a well-known (and easy for them to find out, had they read up) major taboo of the society.