I know, there are tons of people and questions about the new career mode, mostly the tight money system. Most of these posts are answered with "Farm the 'test x while landed on Kerbin' missions, ???, profit" or similar grindy/exploity strategies (my favorite to think about is exploiting the fact that your money can't go negative, essentially defrauding each and every investor that the program gets), but what about for the players that want to be able to achieve progression, while having fun in the process? The more lucrative missions tend to send you off into orbit, or even to the Mun and Minmus (while you still only have the 3 basic 1.25m engines and the half-size liquid fuel tank), or at least high into the atmosphere, where flight is only sustainable with either a high altitude spaceplane, usually requiring the turbojet engine, which is available through no less than 300 science points, or through a traditional Kerbal rocket, which is required to jettison pretty much everything in order to ensure a safe landing, resulting in a huge loss in money on craft recovery (keep in mind, we're assuming that the player has hit a relative wall in science, due to difficulty rustling up the cash for the facility upgrades), usually giving a net loss unless you can manage to hammer out 4 or 5 missions in a single flight (once again, facility upgrading problems).
The question is this: How do I progress in the game without grinding super easy missions or exploiting game quirks (however realistic they may or may not be)? In other words, how do I run an honest space program, while still having fun?