''[[http://orbit.medphys.ucl.ac.uk/orbit.html Orbiter: The Free Spaceflight Simulator]]'' is a [[MohsScaleOfSciFiHardness diamond-hard]] realistic SimulationGame [[ExactlyWhatItSaysOnTheTin involving spacecraft and spaceflight in general]]. It was created by Cambridge tutor Martin Schweiger for educational and entertainment purposes. The simulator has been in development roughly since 2000, and the latest stable version is ''Orbiter 2016'', released on August 30, 2016. The last version, ''Orbiter 2010 (Patch 1)'', was released exactly six years earlier.

Make no mistake, Orbiter is no fast-flyin' laser-shootin' space sim. Think of it rather as ''VideoGame/MicrosoftFlightSimulator'' [[JustForFun/XMeetsY meets]] ''Anime/{{Planetes}}''.

The [[FreewareGames game is freeware]], so if you feel interested in it and [[NintendoHard aren't scared by a steeper learning curve]], you can [[http://orbit.medphys.ucl.ac.uk/download.html grab it here]]. In addition to this basic game pack, there are literally tons and tons of (equally freeware) fan-made mods that expand the game in virtually every way: Adding new launchers, spacecraft, spaceports and space bases, scenarios and campaigns, texture and graphic updates, even entire planets and solar systems, and new [=HUDs=] for the ship's onboard computer... They can be found [[http://www.orbithangar.com/ here]], [[http://francophone.dansteph.com/ here]] and [[http://orbiter.dansteph.com/ here]]. And don't forget the XR series [[http://www.alteaaerospace.com/ here]]!

Not to be confused with ''Pinball/{{Orbitor 1}}''.

!!''Orbiter'' provides examples of:

* AbsentAliens: Unless you're counting the mods based on ''Franchise/StarWars'', ''Franchise/StarTrek'', ''Series/BabylonFive'' or other [[TheVerse verses]], which feature the ships of the various non-human species from those movies and TV shows.
* AlternateHistory: In some of the mods and add-ons (e.g. [[RedScare the Soviet Union narrowly beats the US to the first succesful Moon landing]], [[WhatCouldHaveBeen an Apollo Programme-derived spacecraft lands on Mars in 1985]], etc.). Also, in the default scenarios Mir is still flying, and has been moved into a convenient orbit for lunar ejections.
* AsteroidMiners: The TwentyMinutesIntoTheFuture [[Series/RedDwarf JMC]] Mining Company in scenarios involving the Delta Glider IV add-on.
* [[CoolStarship Cool Spaceplane]]: The entire Delta Glider class. And for some, RealLife spaceplanes, like NASA's [[LongRunners Space Shuttle]], the [[RussianGuySuffersMost ill-fated Russian]] ''Buran'' or [[WhatCouldHaveBeen the never built]] ESA [[FragileSpeedster Hermes space shuttle]].
* CoolStarship / [[CoolStarship Cool Spacecraft]]: Way too many to list...
* GameMod: The main draw of the game. There are literally ''hundreds'', and many of the more high-profile ones are considered by the community to be essential parts of any ''Orbiter'' install, to the point that it's just assumed as a given that any new user will have downloaded them.
* MohsScaleOfSciFiHardness: As hard as humanly possible for a layman-accessible Spaceflight SimulationGame.
* NintendoHard: You are, for all intents and purposes, flying a real spacecraft. It's highly recommended that you have at least a basic grasp of orbital physics and the fundamentals of spaceflight before you even ''think'' of playing the game.
* InterplanetaryVoyage: The whole point of many (if not most) scenarios.
* LikeRealityUnlessNoted
* PresentDay / NextSundayAD / TwentyMinutesIntoTheFuture / TheFuture
** Really, you can set the date to be whatever you want. Also you can use technology across every era of spaceflight, from early spaceflight technology (the Vostok and Apollo programs) to modern tech (the Space Shuttle and Ariane programs) to speculative tech or tech in research and development (the never-implemented Orion engine, the VASIMR engine, solar sails) to advanced tech from ScienceFiction shows and movies (''Franchise/StarWars'', ''Franchise/StarTrek'', ''Series/BabylonFive'', ''Franchise/{{Stargate|Verse}}'', ''Series/{{Battlestar Galactica|2003}}''...)
* QuicksandBox: Once you master the basics, the possibilities offered by the game can get really addictive.
* SpaceBase: Of the non-villainous, planet surface variety.
* SpaceStation: You can even build one !
* {{Terraform}}: In add-ons that replace some of the default planets and moons with terraformed versions.
* WideOpenSandbox: And there is some ongoing talk in the sim's community to create a more persistent "sandbox spaceflight" experience by adding actual objectives for flying missions. (Right now, you just fly and land without any particular end goal but your own.)

!!It is also notable for [[AvertedTrope averting]] these [[TropesInSpace space-related tropes]] :

* TwoDSpace: Very, very averted.
* ArtificialGravity: Unless it's generated by the good old rotation method...
* CasualInterstellarTravel
* ConvenientlyClosePlanet
* DeflectorShields
* DramaticSpaceDrifting
* EasyLogistics
* ExplosionsInSpace
* ExplosiveDecompression
* FasterThanLightTravel: The game uses strictly Newtonian physics, not accounting for relativity, so it is theoretically possible for a ship to exceed the speed of light with standard rocket engines. However, the truly ridiculous amount of fuel you would need makes it a practical impossibility[[note]]Unless you turn on the 'Unlimited Fuel' option[[/note]]. This doesn't count the more fictional mods that DO feature some FTL.
* GravitySucks
* InSpaceEveryoneCanSeeYourFace
* LatexSpaceSuit: At least in the base game. Some mods do replace the EVA model with one more fitting this trope though.
* NoSeatBelts
* SciFiWritersHaveNoSenseOfScale
* SpaceDoesNotWorkThatWay
* SpaceFriction
* SpaceIsMagic
* SpaceIsNoisy: Technically, the core game doesn't come with sounds. The sound addon averts this by default, but gives you the option to play it straight.
** The sound mod only plays sounds while in cockpit view, and then only sounds you'd expect to hear from that perspective: engine noise, cabin ventilation, pilot notifications, et cetera. In third-person view, the sound mod used to play Bach's ''Air on the G String'', but now plays an electronic track known as "calm-spaces." There is a built-in MP3 player that allows you to play other music. You can play such songs as ''Killer Queen'', the Imperial March, the theme for ''Apollo 13'' and many others in-flight.
* SpaceIsAnOcean
* StealthInSpace
* StreamingStars
* SubspaceAnsible