tinyE: Am I to assume there is an adequate save system here, meaning it keeps your designs? I'd hate to think every time I launch I have to go back to step one trying to remember where I put boosters and separators and crap.
Telika: Within one career (one "game" with set rules, and under a given name, or, if you want, one account) you can save anything you want at any point. You can even play for ages, save your modern rockets (and staging orders), and then reload a much older gamesave dating from before half of your tech unlock : your saved rockets will still be on your factory list, ready to be reloaded once you catch up again with the required tech discoveries. Not to mention you can most of time "revert" your mission back to the instant of launch, or back to the moment of rocket design. Okay, it may sound all confusing, but, let's put it that way :
1) The game is very save-friendly.
2) The game is very friendly.
Generally speaking, the game is very.
Now get out and go meet that fedex truck half way.
Don't forget, you can also use F5 and F9 as a quick-save and quick-load. I quicksave before every major milestone of a mission just in case I screw up a landing or my time-compression doesn't decompress on time. (Oh -- also, there's lots of mods. You can fly around the real solar system or even avoid missing time-decompressions. But I have yet to actually use any mods)