To me, it sounds like it might help to dig a bit deeper and find what about that idea captured your attention. What exactly is it that is/was interesting to you? There's always something underneath that initial idea that grabs at us, that sinks itself into our mind, and I think if you find out exactly what that is, everything won't get away so easily.
The scene made perfect sense in my mind. Such a vivid image. I feel what the character feels, i know what he thinks, why he thinks this, etc. Visually, it is relatively powerful. And i felt it would be easy to write (or, well, would be, as i only wrote a summary).
But strictly speaking, the scene is without context. Some sort scifi setting. But i don't have anything else for it, bits and pieces at most (haven't even really tried fitting them together).
And most of all, i'm missing characters, ideas for characters whose story i'd like to write and explore. The only character i have in mind isn't necessarily a good view point character beyond some scenes. And i have no story in mind for him, beyond that scene.
Of course, a scifi story is as much, or perhaps even more, about the world than it is about the characters there.
A roadblock i have for writing scifi (despite loving the genre) is that i still haven't figured out a justification for manned space flight and constant presence of humans in space in a scifi world. Just because is not enough for me (even if it is enough for 99.9% of readers and authors), not when robotic and remote controlled probes can accomplish just about everything far more effectively. Especially with futuristic technology.
Exploring this conflict/dilemma is actually an interesting thing in itself, but it has no relation to what i've written and thought about.
Also, if worrying about what others want to read is making it difficult for you, then heck yes you should just forget about that for this first draft. Write what you want to write. This first draft is for you. You can worry about making it "readable" for others when you edit. Most likely, at that point you'll be able to see what actually needs to be changed instead of feeling all self-conscious throughout the entire process.
Honestly, i shouldn't even think about readability at this point. I don't really have anything but this summary of a chapter, plus various ideas, ideas i'm not even sure i want to fit together.
What you write does sound very reasonable.
(I can't recall why i wrote what i wrote. Guess my mind was darting around... I have noticed being a bit sleepy is beneficial for creativity and thinking. Relaxed mind, you know? Unfortunately, the drawback is that why and how is usually missing afterwards. Not that it is a big deal.)
What i really should do is to work on writing, rather than do it sporadically, only when i have a clear idea what i want to write. But i know i could easily lose myself for hours were i to do that. Not sure i want to do that... Difficult to have time for every interesting thing.
