I am making a video game on-board an old, creaky, leaky space station, which is forgotten or mostly not cared about, drifting around some moon/planet, with a single lonely, weary astronaut on board. I want it isolated and introverted, thoughtful and wistful. A bit like the movies Moon, Silent Running, or 2001 (although not forgotten about, its protagonist is isolated and lonely).
The technology level of the space station is highly realistic, and quite primitive, maybe a bit like Mir. An onboard garden would be ok. Clunky switches and knobs are preferred over holographic displays or touchscreens.
My question to Worldbuilding community is HOW and WHY the station and astronaut came to be in this situation... what events transpired to put him there (and then passed him by, leaving him mostly obsolete?). A core issue I have regards financial realism: How can I justify the expenses and mission importance of placing a manned station somewhere, only to let it fall into obscurity?
The best answers will support the intended atmosphere, and invoke feelings of distance, isolation, and especially the fact that the rest of the world has just moved on, leaving this poor astronaut obsolete. Good answers will not make the astronaut special in any way, he will not be the star in a tragic mission-gone-wrong, nor will he be the victim of unusual circumstance. He's just an ordinary joe stuck with a job no one else wants to do, and pretty much abandoned due to lack of interest in his situation. My core problem is that real space stations are expensive, and require regular resupplies, and so are not very likely to be forgotten or abandoned.. Good answers will explain a way around this economic difficulty.
Good answers probably don't involve him or the ship being very important in the past. Sure, there would have been good reasons for him being deployed in the first place, but good answers explain how and why these reasons faded and became uninteresting. Not broken, not lost, just uninteresting.
Good answers don't involve him pining for home, don't draw attention to home and invoke complicated thinking about home. The astronaut is not trying to escape his fate, he is just doing his daily routine, performing maintenance, but he has accepted his hopeless fate, still performs his role out of a sense of duty, and that's it. Good answers don't invite much speculation into the outside world, and in fact the more boring the answer the better. Plausible shifts of corporate or political interest would be very suitable sources of reasons, as is having the job he was initially sent to do become meaningless, but they keep him there anyway, 'just in case'.
The astronaut isn't about to die. The station can keep him alive as long as he works on its maintenance, which he does. Good answers place the astronaut in a timeless, unchanging existence.
An occasional message from mission control, and regular automated supply drops are permitted. It is ok with alternative timelines, earths and histories, etc, but the technology in use should be clunky and old, but reasonably realistic. Higher levels of technology are acceptable elsewhere in the solar sytem, as long as its nowhere near the astronaut, and could even be used to show how everyone else has moved on, leaving the astronaut behind at his post.
Bonus points if the station is located somewhere with a beautiful view (like Saturns rings).