Since this book doesn’t come out until July, plenty of time to find most of these in their original publications. I’ve attempted to categorize by length but a few of them don’t have enough info online to make that determination so I just guessed.
Novella
The Martian Job, Jaine Fenn (NewCon Press)
The Proving Ground, Alec Nevala-Lee (Analog Jan-Feb)
Prime Meridian, Silvia Moreno-Garcia (Innsmouth Free Press)
Nexus, Michael F. Flynn (Analog Mar-Apr)
Novelette
The Moon is Not a Battlefield, Indrapramit Das (Infinity Wars)
My English Name, R.S. Benedict (F&SF May-Jun)
We Who Live in the Heart, Kelly Robson (Clarkesworld May)
Night Passage, Alastair Reynolds (Infinite Stars)
Uncanny Valley, Greg Egan (Tor.com Aug 9)
Pan Humanism: Hope and Pragmatics, Jess Barber and Sara Saab (Clarkesworld Sep)
The Influence Machine, Sean McMullen (Interzone Mar-Apr)
There Used to be Olive Trees, Rich Larson (F&SF Jan-Feb)
Whending My Way Back Home, Bill Johnson (Analog Jan-Feb)
Death on Mars, Madeline Ashby (Visions, Ventures, Escape Velocities)
A Series of Steaks, Vina Jie-Min Prasad (Clarkesworld Jan)
Short story
An Evening with Severyn Grimes, Rich Larson (Asimov’s Jul-Aug)
Vanguard 2.0, Carter Scholz (Visions, Ventures, Escape Velocities)
Starlight Express, Michael Swanwick (F&SF Sep-Oct)
The Martian Obelisk, Linda Nagata (Tor.com July 19)
Winter Timeshare, Ray Nayler (Asimov’s Jan-Feb)
Dear Sarah, Nancy Kress (Infinity Wars)
The Dragon that Flew Out of the Sun, Aliette de Bodard (Cosmic Powers)
Waiting Out the End of the World in Patty’s Place Cafe, Naomi Kritzer (Clarkesworld Mar)
The Hunger After You’re Fed, James S.A. Corey (Wired Jan)
Assassins, Jack Skillingstead and Burt Courtier (Clarkesworld Feb)
The Road to the Sea, Lavie Tidhar (Sunvault)
The Worldless, Indrapramit Das (Lightspeed Mar)
Zigeuner, Harry Turtledove (Asimov’s Sep-Oct)
Zen and the Art of Starship Maintenance, Tobias Buckell (Cosmic Powers)
Canoe, Nancy Kress (Extrasolar)
The History of the Invasion Told in Five Dogs, Kelly Jennings (F&SF May-Jun)
Triceratops, Ian McHugh (Asimov’s May-Jun)
Mines, Eleanor Arnason (Infinity Wars)
Elephant on Table, Bruce Sterling (Chasing Shadows: Visions of Our Coming Transparent World)
Number Thirty-Nine Skink, Suzanne Palmer (Asimov’s Mar-Apr)
The Last Boat-Builder in Ballyvoloon, Finbarr O’Reilly (Clarkesworld Oct)
The Residue of Fire, Robert Reed (Extrasolar)
Sidewalks, Maureen F. McHugh (Omni, Winter)