This is meant to be a non-exhaustive list, in ~~stream-of-consciousness~~ alphabetical order.

Dedicated systems

• 2300 AD (now a setting for Traveller)
• 3:16: Carnage Amongst the Stars
• Apocalypse World
• BattleTech: A time of war
• Coyote & Crow
• Cyberpunk (2013, 2020, V3.0, Red)
• Eclipse Phase
• Lancer
• Paranoia
• Shadowrun
• SLA Industries
• Star Wars roleplaying (different games by different publishers: WEG d6, d20, FFG NDS)
• Traveller (in its many incarnations throughout the past nearly 50 years and derivatives such as Cepheus, Hostile, Kosmic)
• Warhammer 40K

FATE based systems

• Atomic Robo
• Bulldogs!
• Diaspora
• Mindjammer
• Nova Praxis

OSR/d20 based systems

• CY_BORG
• Mothership
• Starfinder
• Stars/Cities/Ashes Without Number

Year Zero

• Alien: The RPG
• Blade Runner: The RPG
• Coriolis – The Third Horizon
• Mutant: Year Zero

GURPS

A host of modules and supplements named after the subgenre, GURPS-style. GURPS Transhuman Space, Cyberpunk, etc.

Other systems

• BattleTech: Mechwarrior: Destiny (Cue)
• Black Star (d6)
• Dune: Adventures in the Imperium (Modiphius 2d20)
• Fading Suns (VPS)
• Neon City Overdrive (d6)
• Rifts (Palladium)
• Robotech (Palladium)
• Salvage Union (Quest RPG)
• Scum and Villainy (FitD/PbtA)
• Star Trek Adventures (Modiphius 2d20)
• The Expanse RPG (Modern AGE)

Solo friendly

• Hostile (Cepheus/Traveller)
• Ironsworn: Starforged (PbtA)
• Stoneburner

Out of print/No longer developed

• Albedo
• Battlestar Galactica RPG (Cortex Classic)
• Blue Planet
• CORPS
• Firefly RPG (Cortex Plus)
• Gamma World (D&D)
• HARP SF
• Heavy Gear
• High Colonies
• Jovian Chronicles
• Judge Dredd RPG
• Justifiers
• Living Steel
• Metamorphosis Alpha
• Mutant Chronicle
• Other Suns
• Ringworld
• Serenity RPG (Cortex Classic)
• Space Master
• Space Opera
• Star Frontiers
• Universe

Have a suggestion to improve this? Your favorite game missing? Leave a comment.