Confabulated history, brilliant cinematography, heartfelt ficitionalized movie making As is pointed out by others more well versed the history, Amelia Wren is at best a confabulation of one or more actual female aeronauts and of Henry Tracey Coxwell, who apparently saved Glaisher's life and his own. The fact that they survived at all, ascending ten thousand feet above the death zone of the atmosphere, is remarkable, and made possible only by the brevity of the flight and Coxwell's success in getting them to descend. How Coxwell managed it I don't know, but I feel confident in saying that not even Reinhold Meissner could climb to the top of a balloon without oxygen at nearly 37,000 feet, though Coxwell must have done something remarkable to take an action to arrest the balloon's ascent at way over 30,000 feet. I'll leave the history to others better versed on the events.
Having said that, and that I don't blame people who slam the movie for historical liberties, I think it also deserves to be looked at as a movie, and as a piece of Hollywood magic.. Both main characters are compelling, multifaceted people with backstories, placed convincingly in their time and place, in a story related with restraint and a great deal of heart. To pack as much as this movie does in terms of the human journey into a balloon ride no longer than the movie itself is remarkable.
I also think kudos are due to the cinematography. I don't have time to educate myself about how the scenes were filmed, but am going to assume that the balloon scenes were filmed on a sound stage in front of a blue screen. Having said that, although it might be barely possible by use of very advanced drone technology or actual unmanned balloon footage to get those upper atmosphere shots, I think that would be very difficult, let alone usable on a blue screen. However, if they were computer generated, it's a tribute to the craft, and rivaled only by the movie Pi for it's recreation of a magnificent, mostly natural world.
The movie also deserves credit for managing, no doubt with a lot of help from makeup and practical and computer special effects, to simulate the appearance of people actually in the death zone, hypoxic, frostbitten, and mentally impaired, About the only miss - probably not possible to include with the dramatic centerpiece of the film - is the breathlessness, the take one step, stop, catch your breath, take another stop of someone at the level fo Everest. If someone did manage the impossible task of climbing a balloon above 30,000 feet, they would be stopping and gasping every step of the way.
But no matter. As history, it ain't, but as great storytelling, I think it's one of the best movies of the decade, wonderfully acted by both of the principals.