My great-aunt worked at NASA and was friends with several astronauts during Gemini and Apollo. I've heard about the floaters story, and you have an interesting twist with it.
The only thing I'm not 100% on is how long the Captain and Reynolds could survive in that pod--my thinking was closer to minutes or hours rather than days, but the Captain may be disoriented and inaccurate about the timing. First-person POV gives you some room with that, but you could also give them a slight break with some of the pods functions (heat, oxygen, etc.) working but with a very rapid power drain.
I hope you keep going with this, and feel free to send me an email when you have an update. I started out on Writing.com about 12 year ago, and my serial eventually grew into full-length novels. I can see the same happening with this.
Have a great day!