When I first heard that this novella had been commissioned for a collection in which all the stories start with the first sentence from a classic story, and that this story shares a beginning with The Wizard of Oz, I have to admit that I groaned internally.
Sci-Fi mashups -- especially those with a Steampunk bent -- have become quite common. I'm not really keen on them, and I really wasn't that keen on reading an Oz mashup.
But instead of an Oz mashup, this story is ostensibly an original account of a pioneering female astronaut who, in her later years, is once again given the opportunity of going into space on a ground-breaking mission. But there will be a big price for her to pay, in order to once again experience that adventure which she so desperately craves.
And that is what this story is really about: the hard choices we often have to make, either in order to attain our goals, or to sacrifice those goals for some perceived higher purpose. This story is about all the regrets and second-guessing with which we have to live, for the rest of our sometimes excruciatingly-long lives, as a result of those hard choices we make. But it is also about the way those we love have, themselves, the ability to make their own hard choices -- and in doing so, provide us with a measure of salvation which we were not able to choose for ourselves.
This is a quick read, but the author has done a fantastic job of creating vividly-detailed characters and an interesting background with a small number of words, and it is well worth the read.
(Note that all the wonderful Tor Originals can also be found at their website for free.)