Past related threads—I think there may have been others also:

A Scary Light Show: Exploding H-Bombs in Space (2010) - https://news.ycombinator.com/item?id=21853823 - Dec 2019 (2 comments)

Starfish Prime - https://news.ycombinator.com/item?id=19096803 - Feb 2019 (3 comments)

In the summer of 1962, the U.S. blew up a hydrogen bomb in outer space - https://news.ycombinator.com/item?id=14671438 - June 2017 (70 comments)

A Very Scary Fireworks Show: Exploding H-Bombs In Space - https://news.ycombinator.com/item?id=1488320 - July 2010 (24 comments)

Starfish Prime, outer space nuclear test - https://news.ycombinator.com/item?id=1478114 - July 2010 (24 comments)