View source for Orbiter (simulator)

{{Short description|2000 video game or Solar System Simulator}}
{{italic title}}
{{use dmy dates|date=June 2019}}
{{Infobox software
| name = Orbiter Space Flight Simulator
| title = ''Orbiter Space Flight Simulator''
| screenshot = Shuttle lift-off in Orbiter.jpg
| logo = Orbiter BasicLogo.png
| caption = Orbiter simulation of {{OV|104}} lifting off from [[Kennedy Space Center Launch Complex 39]]
| logo size = 300
| collapsible = yes
| developer = Martin Schweiger
| released = {{Start date and age|2000|11|27|df=yes}}
| programming language = [[C++]]<ref name="FAQ"/>
| operating system = [[Windows Vista]] and later
| size = {{Nowrap|2.7 GB}}
| language = [[English language|English]]
| genre = [[Simulation]]
| license = [[MIT license]]
| repo = {{URL|https://github.com/mschweiger/orbiter}}
| website = {{URL|orbit.medphys.ucl.ac.uk}}
}}
'''''Orbiter''''' is a [[space flight simulation game|space flight simulator]] program developed to simulate [[spaceflight]] using realistic [[Newtonian physics]]. The simulator was released on 27 November 2000;<ref>{{cite web|access-date=2020-08-30|title=ORBITER Change Log|url=http://orbit.medphys.ucl.ac.uk/change.html|date=2005-12-10|archive-url=https://web.archive.org/web/20051210044240/http://orbit.medphys.ucl.ac.uk/change.html|archive-date=10 December 2005}}</ref> the latest edition, labeled "Orbiter 2024", was released on 31 December 2024.<ref name="stable">{{Cite web | title=Orbiter 2024 Release {{!}} Orbiter Forum | url=https://www.orbiter-forum.com/threads/orbiter-2024-release.42062/ | access-date=2025-08-30 | website=www.orbiter-forum.com}}</ref> On 27 July 2021, its developer, Martin Schweiger, announced to the community that ''Orbiter'' is being published under open source [[MIT License]].<ref>{{cite web|url=https://www.orbiter-forum.com/threads/orbiter-is-now-open-source.40023|title=Orbiter is now open source|date=27 July 2021|website=Orbiter-forum.com|publisher=Martin Schweiger|access-date=20 October 2022}}</ref>

''Orbiter'' was developed by Martin Schweiger, a senior research fellow in the computer science department at [[University College London]],<ref name="UCL">[http://www0.cs.ucl.ac.uk/people/M.Schweiger.html Martin Schweiger]</ref> who felt that space flight simulators at the time were lacking in realistic [[physics]]-based flight models, and decided to write a simulator that made learning physics concepts enjoyable.<ref name=OrbiterInterview>{{cite web|url=http://techhaze.com/2010/06/interview-with-orbiter-sim-creator-martin-schweiger/|title=Techhaze interview with Martin Schweiger|access-date=2010-08-05|archive-url=https://web.archive.org/web/20130517094635/http://techhaze.com/2010/06/interview-with-orbiter-sim-creator-martin-schweiger/|archive-date=17 May 2013|url-status=dead}}</ref> It has been used as a teaching aid in classrooms,<ref name="OrbiterInterview"/> and a community of add-on developers have created a multitude of add-ons to allow users to fly assorted real and fictional spacecraft and add new planets or [[planetary system]]s.<ref name=OrbiterReview>{{cite web|url=https://www.thespacereview.com/article/494/1|title=The Space Review|access-date=2010-08-05}}</ref><ref name=OrbiterKluempers>{{cite web|url=http://www.kluempers.org/simulators.html|title=David Kluemper<nowiki>'</nowiki>s Simulators|access-date=2010-08-07|archive-url=https://web.archive.org/web/20160303224123/http://www.kluempers.org/simulators.html|archive-date=3 March 2016|url-status=dead}}</ref>

==About the simulator==

===Features===
''Orbiter'' is a realistic physics simulator which allows users to explore the [[Solar System]] in a number of [[spacecraft]], both realistic, such as the {{OV|104}}; and fictional, such as the "Delta-Glider."<ref name=OrbiterReview /> Schweiger has included fictional spacecraft to allow for easier flights for less experienced users.<ref name=OrbiterInterview /> The simulator is realistic enough to re-enact historical space flights, and the ability to fly fictional ships also allows the player to reach areas of the [[Solar System]] that cannot be reached by human spaceflight at the present time.

A spacecraft's engines are defined only by the amount of thrust they put out and amount of fuel they use, allowing anything from [[solar sail]]s to conventional [[rocket engines]] to futuristic [[nuclear reactor|nuclear fission]] and [[Nuclear fusion|fusion]] drives to be simulated. Everything between ground movement and interplanetary travel is supported, including orbital and sub-orbital flight, although only vessel-ground collisions are supported.<ref name=OrbiterInterview /> Docking and attachment systems allow the user to simulate docking with a [[space station]] or other spacecraft, and rendezvous with and retrieval of [[satellites]].<ref name=OrbiterManual>{{cite web|url=http://orbit.medphys.ucl.ac.uk/download/Orbiter.pdf|title=Orbiter Manual |access-date=2009-04-17}}</ref> Users can also build [[space station]]s in orbit.<ref name=OrbiterManual />

The Solar System as presented in ''Orbiter'' consists of the [[Sun]], the eight [[planet]]s and their major [[Natural satellite|moons]].<ref name=OrbiterWiki>{{cite web|url=https://www.orbiterwiki.org/wiki/Orbiter|title=Orbiter Wiki|access-date=2010-08-07}}</ref> Many [[dwarf planet]]s, [[asteroid]]s (except [[4 Vesta|Vesta]]), and [[comet]]s not included in the simulator are available as add-ons.<ref name=OrbiterTechmixer>{{cite web|url=http://www.techmixer.com/free-spacecraft-flight-simulator-pc-game-orbiter/|title=Techmixer Review|date=8 September 2009|access-date=2010-08-05}}</ref><ref name=OHMPlanets>{{Cite web|url=https://www.orbithangar.com/searchresults.php?category=3&subcat=14&OrbVer=default|title=Scenery - Planets, Rocks|website=www.orbithangar.com|access-date=2019-06-15}}</ref> Although ''Orbiter'' contains a database of over 100,000 stars, these are for display purposes only and [[interstellar travel]] is currently not possible in the simulator.<ref name="FAQ">{{cite web|url=http://orbit.medphys.ucl.ac.uk/faq.html|title=Orbiter FAQ|access-date=2018-10-11}}</ref> The simulator also includes a planetarium mode that allows [[ecliptic]] and [[Sky|celestial]] grids to be overlaid onto the star map, along with labels of the [[constellation]]s and other celestial markers.<ref name=OrbiterManual /> The planetarium mode can also display labels indicating the location and identity of objects in the Solar System, such as planets, moons, or vessels, that appear within a certain proximity based on their type. This mode can also display labels on the celestial bodies in the Solar System at certain coordinates on their surface for indicating cities, historical markers, geological formations, and other interesting sites.<ref name=OrbiterManual />

[[Image:Orbiter 2010P1 atmospheric effects with ISS.JPG|thumb|300px|A Deltaglider docked to the [[ISS]], demonstrating Orbiter's atmospheric visual effects]]

The traditional simulated control interface in ''Orbiter'' consists of two [[multi-function display]]s and a [[head-up display]].<ref name=OrbiterKluempers /> Each features several modes of operation, with all commands given via the [[Computer keyboard|keyboard]] or mouse. The simulator also supports customized control panels and instruments, including 3-D virtual cockpits and 2-D instrument panels.<ref name=OrbiterTechmixer /> These allow the player to use the mouse to interact with the panels, and allows more complex systems and instruments that are customized for each ship. The addition of a virtual [[cockpit]] also allows the player to freely look around from the perspective of the pilot. Since ''Orbiter 2006 Patch 1'', it has supported [[TrackIR]], which allows the simulator to track the head-movements of the player and adjust the view accordingly.<ref name=TrackIR>{{cite web|url=https://www.naturalpoint.com/trackir/03-enhanced-games/game-orbiter.html|title=TrackIR Webpage|access-date=2010-08-07}}</ref>

===Realism===
''Orbiter'' was developed as a [[simulator]],<ref name=InstantFundas>{{cite web|url=https://www.instantfundas.com/2009/02/orbiter-realistic-free-space-flight.html|title=Instant Fundas Review|date=19 February 2009|access-date=2010-08-07}}</ref> with accurately modeled planetary motion, [[gravitation]] effects (including non-spherical gravity), free space, atmospheric flight and [[orbital decay]].<ref name="OTN Dynamic State">"Orbiter Technical Notes: Dynamic State Vector Propagation", Martin Schweiger, 2006</ref><ref name="VSOP87">P. Bretagnon and G. Francou, [http://articles.adsabs.harvard.edu/cgi-bin/nph-iarticle_query?1988A%26A...202..309B&data_type=PDF_HIGH&type=PRINTER&filetype=.pdf "Planetary theories in rectangular and spherical variables. VSOP87 solutions"] (PDF 840KB), Astronomy & Astrophysics 202 (1988) 309–315.</ref> The position of the planets in the solar system is calculated by the [[VSOP87]] solution, while the Earth-Moon system is simulated by the [[ELP2000]] model.<ref name=MartinSchweigerPresentation>{{cite web|url=http://orbit.medphys.ucl.ac.uk/press/orbiter.pdf|title=Orbiter: A Free Spacecraft Simulation Tool|access-date=2010-08-07}}</ref> Only n-body [[Newtonian mechanics]] are simulated, not taking [[General relativity|relativistic effects]] into account. This means that phenomena such as [[time dilation]] due to [[special relativity|relativistic effects]] are not simulated.<ref name=OrbiterInterview />

The default version of ''Orbiter'' before the 2024 edition had no sound,<ref name=FAQ /> however popular add-ons called OrbiterSound<ref name=Orbitersound>{{cite web|access-date=2020-08-30|title=Dan's Orbiter page|url=http://orbiter.dansteph.com/index.php?page=download|website=orbiter.dansteph.com}}</ref> and XRSound<ref name=AlteaAerospace/> are available. Both of them provide engine noises, ambient sounds in the cabin, radio chatter and other sounds including playlists. Both of them contain options to maintain a realistic silence when the craft is viewed externally during spaceflight. There is no collision detection for objects in space, apart from defined docking ports. Since ''Orbiter 2024'', XRSound is now included in the base package, but must be enabled in the launchpad options to function.<ref>{{cite web|access-date=2025-01-20|title=GitHub commit merging XRSound into Orbiter repository|url=https://github.com/orbitersim/orbiter/commit/a585b0c4c8fff9657356e6abe63efab919492b61|website=github.com}}</ref>

Since ''Orbiter 2016'', terrain elevation is modeled for Earth, the Moon, and Mars. Support was also added for higher definition surface textures and clouds.<ref>{{Cite web|title=Orbiter - Download|url=http://orbit.medphys.ucl.ac.uk/download.html|access-date=2021-02-04|website=orbit.medphys.ucl.ac.uk}}</ref>

==Included spacecraft==
''Orbiter'''s standard distribution includes real and fictional spacecraft and space stations:

===Real vessels===
;{{OV|104}}: The ''Orbiter'' version of the Space Shuttle ''Atlantis'', a retired Space Shuttle orbiter formerly operated by [[NASA]], and the only player-controllable spacecraft based on a real world design that is included with the basic installation of ''Orbiter''.
;[[Space Station]] ''[[Mir]]'': ''Orbiter'''s model of the historic Russian space station. Unlike its real counterpart, it was not deorbited and is placed in an orbit which is closer to the ecliptic plane. This was done initially to make ''Mir'' a good origin of interplanetary flights in earlier versions of ''Orbiter'', when ''Orbiter'' also automatically refueled spacecraft on docking with a space station. Using the scenario editor, it's still possible to refuel in-flight or start the simulation docked and with full tanks. However, it is possible to move Mir into the correct orbit.
;[[International Space Station]]:In a similar orbit as the real ISS and in a completed state, it shows modules which are no longer planned to be installed on the real ISS.
;[[Hubble Space Telescope]] (HST): A model of the real HST, it gets used together with ''Orbiter'''s Space Shuttle ''Atlantis''.
;[[Long Duration Exposure Facility]] (LDEF) Satellite: Like the Hubble Space Telescope, it's one of the example payloads for ''Orbiter'''s Space Shuttle.

===Fictional vessels===
[[Image:VirtualCockpit.jpg|thumb|300px|The Delta Glider in an orbit around [[Venus]], showing the 3D Virtual Cockpit, including [[multi-function display]]s (MFDs) and the [[head-up display]] (HUD)]]

;Delta-Glider (DG): A [[delta wing]] [[spaceplane]], which is rather easy to fly and thus good for the first steps into ''Orbiter''. A variant of the Delta-glider is also included, the Delta-Glider-S (DG-S), which trades some of the propellant capacity for a [[scramjet]] propulsion system, at the cost of requiring fuel from the main engine fuel tank. It's possible to travel from Earth to Mars with the DG, making it possible to practice interplanetary missions. It is technically a [[single-stage-to-orbit]] spaceplane.
;Shuttle-A: A small space freighter, which can transport six large cargo containers with a total mass of {{Convert|120|t|lb}}. It does not have an aerodynamic hull so it is at home on the Moon and Mars. While it is possible to launch and land the spacecraft from Earth, particularly when empty, the lack of aerodynamic lift coupled with Earth's high gravity and thick atmosphere make this a difficult and fuel-costly operation. Its cargo containers are however equipped with automatic parachutes. Using the parachutes, it's possible to simulate a cargo run from a lunar base to Earth and back, dropping the cargo while still in the upper atmosphere. Its high inertia and inferior aerodynamics make it harder to fly in an atmosphere than the Delta-glider. 
;Shuttle-PB: A small personal spacecraft, with high agility and a futuristic performance. As its main purpose is to serve as simple SDK example for add-on developers, it lacks many complex details of other included ships in ''Orbiter'' like 2D or 3D cockpits or animations.
;Dragonfly: A complex crewed [[space tug]] for the construction of [[space station]]s. It simulates its various subsystems at a higher complexity than all other standard spacecraft in ''Orbiter'', being a good example of the technical possibilities of ''Orbiter'''s [[software development kit|SDK]]. Its flight model is also within the possibilities of current technology, making it a so-called "nearly realistic" spacecraft.
;Luna-OB1: A fictional wheel shaped station in lunar orbit, inspired by Space Station V from the beginning of ''[[2001: A Space Odyssey (film)|2001: A Space Odyssey]]''. It consists of a wheel, attached to a central hub with two spokes. The wheel has a diameter of {{convert|500|m}} and is spinning at a frequency of one cycle per 36 seconds, providing its occupants with a [[centrifugal acceleration]] of {{Cvt|7.6|m/s2}}.

;Carina: A small fictional science satellite, which is used as payload on ''Orbiter'''s Space Shuttle. It is a completely inert payload currently. It is based on a proposed European re-entry capsule experiment, to be launched on the [[Ariane 4]], which later resulted in the [[Atmospheric Reentry Demonstrator|ARD]].<ref>{{Cite web|url=http://www.astronautix.com/e/esaacrv.html|archive-url=https://web.archive.org/web/20161228002909/http://astronautix.com/e/esaacrv.html|url-status=dead|archive-date=28 December 2016|title=ESA ACRV|website=www.astronautix.com|access-date=2019-06-25}}</ref>

==''Orbiter'' add-ons==
[[Image:Mercury1-large.jpg|thumb|300px|''Orbiter'' recreation of a launch using an add-on that recreates the [[Mercury-Atlas 6]] mission]]
An extensive [[API]] enables ''Orbiter'' users to contribute by creating add-ons. Many spacecraft are available for download as add-ons, ranging from the [[Soviet Union|Soviet]] [[Vostok spacecraft]]<ref>{{Cite web |title=Vostok v1.1 |url=https://www.orbiter-forum.com/resources/vostok-v1-1.2923/ |access-date=2023-03-28 |website=www.orbiter-hangar.com}}</ref> to [[Apollo program]].<ref>{{Cite web|url=https://www.acsoft.ch/AMSO/amso.html|title=Freeware AMSO pour Orbiter|website=www.acsoft.ch|access-date=2019-06-15}}</ref> Another popular category of add-ons are modifications of the standard spacecraft of ''Orbiter'', ranging from simple visual changes to complex simulations of the internal subsystems of these fictional crafts. Examples of these more advanced default spacecraft include the XR Series of vessels.<ref name=AlteaAerospace>{{cite web |url=https://www.alteaaerospace.com/|title=Altea Aerospace|access-date=2015-02-01}}</ref>

Add-ons are also available for new surface bases,<ref>{{Cite web |title=Scenery - Surface Bases |url=https://orbiter-forum.com/resources/categories/scenery.6/ |access-date=2023-03-28 |website=www.orbiter-forum.com}}</ref> [[multi-function display|MFD]] modes,<ref>{{Cite web |title=Utilities - MFDs |url=https://orbiter-forum.com/resources/categories/utilities.10/ |access-date=2023-03-28 |website=www.orbiter-forum.com}}</ref> extensions of the simulation menu, space stations,<ref>{{Cite web |title=Spacecraft - NASA (spacecraft/stations) |url=https://orbiter-forum.com/resources/categories/spacecraft.2/ |access-date=2023-03-28 |website=www.orbiter-forum.com}}</ref> planets,<ref name=OHMPlanets/> and even other planetary systems.<ref>{{Cite web|url=https://www.orbithangar.com/searchresults.php?category=3&subcat=13&OrbVer=default|title=Scenery - Systems|website=www.orbithangar.com|access-date=2019-06-15}}</ref> Since ''Orbiter 2006'', a scenario editor is included, which can also be extended for supporting the special attributes of add-on vessels.<ref name=OrbiterSpaceDaily>{{cite web|url=https://www.spacedaily.com/reports/Orbiter_2006_Freeware_Space_Flight_Simulator_Released.html|title=Orbiter 2006 Freeware Space Flight Simulator Released|access-date=2010-08-27}}</ref> A third party modlist installer by orbiter-mods.com called Orb can be used to automatically install mod bundles.<ref>{{Cite web |title=orb v1 |url=https://orbiter-mods.com/view/21/orb-v1 |access-date=2023-06-13 |website=orbiter-mods.com |language=en}}</ref>

==See also==
*[[Space flight simulation game]]
**[[List of space flight simulation games]]
*[[Microsoft Space Simulator]]
*[[Kerbal Space Program]]
*[[SpaceEngine]]
*[[OpenUniverse]]
*[[Celestia]]
*[[Systems Tool Kit]]

==References==
{{Reflist}}

==External links==
* {{Official website}}
** [http://orbit.medphys.ucl.ac.uk/download/Orbiter.pdf Orbiter: Manual]
* [https://www.orbiter-forum.com/ Orbiter forum]
* [https://www.orbiterwiki.org/wiki/Main_Page Official wiki]
* [https://orbiter-mods.com Orbiter mods] mods repo and automated modlist installer: ''Orb''
* [https://www.orbiter-forum.com/resources/ Official add-on repository]
* {{cite web |display-authors= 0 |first= Bruce |last= Irving |url= https://www.thespacereview.com/article/494/1 |title= Review: Orbiter space flight simulator |website= Space Review |date= Nov 14, 2005}}
* {{cite web |display-authors= 0 |first= Raimondo |last= Pictet |url= http://techhaze.com/2010/06/interview-with-orbiter-sim-creator-martin-schweiger |title= Interview with creator Martin Schweiger |website= Tech Haze |date= June 2010 |url-status= unfit |archive-date= May 17, 2013 |archive-url= https://web.archive.org/web/20130517094635/http://techhaze.com/2010/06/interview-with-orbiter-sim-creator-martin-schweiger/ }}

{{Space Shuttle}}

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[[Category:2000 video games]]
[[Category:Open-source video games]]
[[Category:Windows games]]
[[Category:Windows-only games]]
[[Category:Video games developed in the United Kingdom]]
[[Category:Space flight simulator games]]
[[Category:Lua (programming language)-scripted video games]]
[[Category:Freeware games]]
[[Category:Realistic space simulators]]
[[Category:Aerospace engineering software]]