This reminds me strongly of a short story I never read, but my brother Steve told me about many years ago. Someone crash lands on a desolate planet. There is no real way to get off the planet and rejoin her loved ones, short of using an emergency kit, so she uses it. This kit destroys her "I am crash landed" self and at the same time, creates a copy of her back on earth. I don't know the name of the story or the author.