Omega

bellevue.nzz.ch www.nzz.ch

For what i know is that someone from the Nasa walked in a watch boutique and ask an employer which watch is very good and can deal with harsh conditions.
He or she took the speedmaster to the lab and tested if the Omega could be go on a mission to the moon.
There where a few others, but Omega was the best tested watch.
Sure, it is a no brainer 😎

"This watch is also a slice of history. In the early 1970s, Nasa astronaut Colonel William Pogue was assigned to crew the first US space station, Skylab. In testing, Pogue did not have access to a standard-issue Omega Speedmaster as these weren’t supplied to astronauts until nearer launch. As an alternative, he bought a Seiko 6139 – the brand’s first automatic chronograph. Pogue liked it so much that in November 1973, when his time came to blast off for Skylab, he packed his new Speedmaster but also took his beloved Seiko without seeking Nasa approval. The 6139 thus became the first automatic chronograph in space. “I had been using the Seiko for well over six months (perhaps over a year) and had found it very handy for timing engine burns,” he would later explain in a letter to watch enthusiast David Bruno. And, Pogue continued, “the self-winding mechanism worked fine in zero-G.”"

Again i learned more about watches who where in space.

Than i give you also knowledge.
Dutch astronaut Andre Kuypers wore a R O watch in the spaceshuttle.
R O is an independent who produce all in house.
R O made special complications for Andre to time typical things which are in earth orbit.
R O you can see as a kind of Grönefeld, but then more affordable.
Compare it in the same way as Omega and Seiko.