That movie is “Flight of the Eagle” about the Andrée balloon expedition of 1897. Haven’t seen it yet (although now you’ve inspired me to start looking) but I did read a good book about Andrée (Alec Wilkinson - “The Ice Balloon”) a couple of years ago.
Thank you, Eric! I need to write that down. I wonder if it’s available on dvd. If not, Criterion better move its rearend!