Yeah, those record missions suck.

The worst one IMO was the planet hostility one, because nobody seems to know where that number comes from and you can't even experiment because it doesn't show anywhere except in the record itself.

Bad weather seems to be a factor but I've seen planets with horrendous storms not count, and some say aggressive sentinels is important but others found high-rated planets with calm sentinels.

Oh, and of course the low pH blood record that didn't even register for a while.

When I had enough I looked for bases left by helpful people with names like "hot planet", "rare animal", "portal" etc, then glyphs for the few I was still missing. On your own this expedition is hell.