I don't normally plan my reading much ahead of time but August is an exception on a few counts.
Firstly, Whalefall by Daniel Kraus comes out on August 8th. It's such a goofy idea for a story (think Jonah and the Whale meets The Martian) and I have been so pumped, I've been talking people's ear off about it for months. It's like scientifically accurate Pinocchio.
Secondly, one of the bookclub picks for the Discord server affiliated with !bookclub@lemmy.world is The Left Hand of Darkness by Ursula K LeGuin
And then it's Tropeical Readathon (a semiannual reading challenge thing) again so I have a couple dozen books picked out to cover that, but the only other sci-fi one apart from the above is Under This Forgetful Sky by Lauren Yero.