It's a story about a boy who is into science and transhumanism, and a girl he told about all these crazy things that were going to happen. He dies and all of the things he said started to happen. She ended up floating around Saturn remembering him.
Either he or she was in the wheelchair. He was dying and he was disappointed he was dying because of all the cool stuff that was going to happen that she was going to be around for, and some of it had to do with whatever problem she had that was going to get fixed.
Please help me find this story if you can.