Our rankings are cleverly generated from the algorithmic analysis of thousands of customer reviews about products, brands, merchant’s customer service levels, popularity trends, and more. The rankings reflect our opinion and should be a good starting point for shopping. By purchasing the products we rank, you’ll get the lowest price we found while we may receive a commission at no cost to you, which will help us continue to provide you with value.
Best Choice 
Contact: Echoes in the Dark: Hard Science Fiction Best Value 
The Receiver: A Hard Sci-Fi First Contact Techno-Thriller 
The Object: Hard Science Fiction Independently published 
The Shackleton Signal: Hard SF Thriller 
Exodus (The Exodus Trilogy Book 1) Primordial Press 
Primordial Threat: A Hard Science Fiction Thriller (The Exodus Series Book 1) Hard-SF.com 
The Enceladus Mission: Hard Science Fiction (Ice Moon Book 1) Quartermaster Press Darwin's Dilemma: A Metaphysical Hard Sci-fi AI Technothriller Hard-SF.com The Atacama Incident: Hard Science Fiction Hard-SF.com The Disturbance: Hard Science Fiction Exemplar: Hard Science Fiction: The Autonomous Sequence (Book 1) Exodus Blue: A Posthumanism Hard Science Fiction Novel with AI and Mystery (The Colour of Blood Book 1) Hard-SF.com The Torn Planet: Hard Science Fiction (The Marchenko Logfiles Book 1) Hard-SF.com The Luna Monolith: Hard Science Fiction (The Black Monolith Book 1) Pygmalion Media Generations: A Science Fiction Mystery Thriller The Mars Anomaly: Hard Science Fiction Primordial Press Freedom's Last Gasp: A Hard Science Fiction Thriller (The Exodus Series Book 2) Echoes of Time: A Science-Fiction Thriller (Epic of Atlantis Book 1) Futureword Publishing Blue SunRise: A Riveting Character-driven Hard Sci-fi Adventure (Blue Sun Space Opera Book 1) Green Hill Publishing Homo Machina: A Post-Apocalyptic Hard Sci-fi Genetic Engineering Thriller Uphill Downhill Press, LLC Wine Dark Deep: A Hard Science Fiction Space Opera - Book One: 1 Hard-SF.com The Dead Planet: Hard Science Fiction (The Marchenko Logfiles Book 4) Sentient Vessels: Hard Sci-Fi Ship Diaries from Deep Space Xenophile Press Oblivion Threshold: A Military Science Fiction Space Opera Epic (The Oblivion Saga Book 1) A7L Thrilling Books Limited The Genesis Signal: Science Fiction Thriller Hard-SF.com The Frozen Planet: Hard Science Fiction (The Marchenko Logfiles Book 2) Hard-SF.com The Hole: Hard Science Fiction (Solar System Series Book 1) Vinci Books The Visitor: First Contact Hard Science Fiction Cosmic Entanglement Media The Foundry: A Hard-Science Fiction Space Opera (Book 1) Yesterday's Thief: An Eric Beckman Paranormal Sci-Fi Thriller Science Fiction Books Phantom 500: A Hard Science Fiction Space Opera Epic (The Origin Series Book 1) Hard-SF.com The Shared Planet: Hard Science Fiction (The Marchenko Logfiles Book 3) BEYOND PROXIMA CHRONICLES BOOK ONE: THE LAST MIGRATION: A Hard Science Fiction Novella Instrumental: Hard Science Fiction: The Autonomous Sequence (Book 2) The Second Human Extinction Event: Will The Sun Rise or Set On Humanity? Tachyon: The Weapon: Hard Science Fiction Hard-SF.com The Luna Monolith 3: Hard Science Fiction (The Black Monolith) Hard-SF.com The Factory of God: Hard Science Fiction (The Dark Cloud Book 1) Hard-SF.com The Titan Probe: Hard Science Fiction (Ice Moon Book 2) Hard-SF.com The Bastion of God: Hard Science Fiction (The Dark Cloud Book 2) Hard-SF.com Andromeda: The Encounter: Hard Science Fiction (The Long Journey Book 1) Hard-SF.com The Portal: Hard Science Fiction (Portal to Xibalbá Book 1) Broken Earth Rogue (Book 1 of The Rogue Series) Hard-SF.com The Krill Enigma: Hard Science Fiction Hard-SF.com Proxima Rising: Hard Science Fiction Hard-SF.com The Triton Disaster: Hard Science Fiction (Solar System Series Book 4) Hard-SF.com The Disturbance 2: The Answer: Hard Science Fiction The Rift: A Science-Fiction Thriller Epic Realms Press Lost Planet (Starship of the Ancients Book 2): A Space Opera Adventure Hard-SF.com Mars Nation 1: Hard Science Fiction (Mars Trilogy) The Meteor: Science Fiction Thriller Hard-SF.com The Clouds of Venus: Hard Science Fiction (Solar System Series Book 5) Hard-SF.com The Portal 2: Hard Science Fiction (Portal to Xibalbá) Hard-SF.com The Luna Monolith 2: Hard Science Fiction (The Black Monolith) Hard-SF.com Mars Nation 2: Hard Science Fiction Hard-SF.com The Disturbance 3: The Truth: Hard Science Fiction Hard-SF.com The Pluto Debacle: Hard Science Fiction (Solar System Series Book 8) Tachyon 3: The Planet: Hard Science Fiction CYI Publishing MY DIGITAL SOUL: A Genre-Bending Hard Science Fiction/Mythological Horror Novel Hard-SF.com The Portal 3: Hard Science Fiction (Portal to Xibalbá) Hard-SF.com Proxima Trilogy: Part 1-3: Hard Science Fiction The Wooden Pen Press The Proteus Bridge - A Hard Science Fiction AI Adventure (The Sentience Wars) Hard-SF.com Proxima Dying: Hard Science Fiction (Proxima Trilogy Book 2) Hard-SF.com The Wrath of God: Hard Science Fiction (The Dark Cloud Book 4) Hard-SF.com Mars Nation 3: Hard Science Fiction (Mars Trilogy) Hard-SF.com Amphitrite: The Black Planet: Hard Science Fiction (Planet Nine Book 1) A. Nation Books FOUND (Hard Science Fiction with Deep space exploration - Domino Book 4): The Lost Ones RESET: Science Fiction Thriller independently published Starship Sakira (Delphi in Space Book 1) The Wooden Pen Press Venusian Uprising - A Military Hard Science Fiction Epic (Aeon 14 - The Sol Dissolution Book 1) Hard-SF.com Amphitrite 2: The Black Planet: Hard Science Fiction (Planet Nine) Hard-SF.com The Death of the Universe: Hard Science Fiction (Big Rip Book 1) Hard-SF.com The Beacon: Hard Science Fiction (Solar System Series Book 7) Anthem Press No Way Home: A Lost Starship Sci-Fi Adventure: (A Standalone Novel) (Scott Standalones) Hard-SF.com The Rift: Hard Science Fiction (Solar System Series Book 3) Gollancz Permutation City: The incredible, mind-bending look at cyberspace, afterlife and immortality from one of the greats of s Tachyon 2: The Ship: Hard Science Fiction Hard-SF.com The Uranus Fiasco: Hard Science Fiction (Solar System Series Book 9) The Fossil: Science Fiction Thriller (Secrets Of Mars Book 1) Keith McIntosh Oberon's Calling: The Birth of Nick Jones: A Science-Fiction Action Thriller (The Nick Jones Saga Book 1) Keith McIntosh Oberon's Calling: The Birth of Nick Jones: A Science-Fiction Action Thriller (The Nick Jones Saga Book 1) Hard-SF.com Return to Enceladus: Hard Science Fiction (Ice Moon Book 4) -
Settlers The Wooden Pen Press Storming the Norse Wind - A Hard Military Science Fiction Assault (Aeon 14: Origins of Destiny) Hard-SF.com Silent Sun: Hard Science Fiction (Solar System Series Book 2) Hard-SF.com Amphitrite 3: The Black Planet: Hard Science Fiction (Planet Nine) Hard-SF.com Andromeda: The Sojourn: Hard Science Fiction (The Long Journey Book 2) Hard-SF.com The Jupiter Catastrophe: Hard Science Fiction (Ice Moon Book 5) 31% Off Jennifer Estep Only Hard Problems: A Galactic Bonds book: 3 -
Hard Hunted Tor UK Children of Time: Children of Time Book 1: The 10th Anniversary Edition of the Arthur C. Clarke Award winning science fi Protected Books 2025 SciFi Anthology: The Science Fiction Novelists (The Science Fiction Novelists SciFi Anthology Series Book 5) A Hard Reset (The System Integration Chronicles Book 1) Hard-SF.com The Death of the Universe: Ghost Kingdom: Hard Science Fiction (Big Rip Book 2) Hard-SF.com The Dark Spring: Hard Science Fiction (Solar System Series Book 6) Hard-SF.com Andromeda: The Arrival: Hard Science Fiction (The Long Journey Book 3) The Wooden Pen Press Lyssa's Run - A Hard Science Fiction AI Adventure (The Sentience Wars Book 2) Knotted Road Press Fleets of Vengeance (The Science Officer Book 15) Hard-SF.com The Io Encounter: Hard Science Fiction (Ice Moon Book 3) -
Hardcore Henry