''Orbiter'' is a

space flight simulator A space flight simulation is a genre of flight simulator video games that lets players experience space flight to varying degrees of realism. Common mechanics include space exploration, space trade and space combat. Overview Some games in the g ...

program developed to simulate

spaceflight Spaceflight (or space flight) is an application of astronautics to fly spacecraft into or through outer space, either with or without humans on board. Most spaceflight is uncrewed and conducted mainly with spacecraft such as satellites in or ...

using realistic

Newtonian physics Classical mechanics is a physical theory describing the motion of macroscopic objects, from projectiles to parts of machinery, and astronomical objects, such as spacecraft, planets, stars, and galaxies. For objects governed by classical mech ...

. The simulator was released on 27 November 2000; the latest edition, labeled "Orbiter 2016", was released on 30 August 2016, the first new version of the simulator since 2010.http://orbit.medphys.ucl.ac.uk/press/pressrelease2016.pdf On 27 July 2021, Dr Schweiger announced to the Orbiter Community that Orbiter is being published under open source MIT license. ''Orbiter'' was developed by Martin Schweiger, a senior research fellow in the computer science department at

University College London , mottoeng = Let all come who by merit deserve the most reward , established = , type = Public research university , endowment = £143 million (2020) , budget = ...

,Martin Schweiger
/ref> who felt that space flight simulators at the time were lacking in realistic

physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

-based flight models, and decided to write a simulator that made learning physics concepts enjoyable. It has been used as a teaching aid in classrooms, 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 A planetary system is a set of gravitationally In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interacti ...

About the simulator

Features

''Orbiter'' is a realistic physics simulator which allows users to explore the

Solar System The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...

in a number of

spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...

, both realistic, such as the ; and fictional, such as the "Delta-Glider." Schweiger has included fictional spacecraft to allow for easier flights for less experienced users. 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

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 Solar sails (also known as light sails and photon sails) are a method of spacecraft propulsion using radiation pressure exerted by sunlight on large mirrors. A number of spaceflight missions to test solar propulsion and navigation have been p ...

s to conventional

rocket engines A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance ...

to futuristic

nuclear fission Nuclear fission is a reaction in which the nucleus of an atom splits into two or more smaller nuclei. The fission process often produces gamma photons, and releases a very large amount of energy even by the energetic standards of radio ...

and

fusion Fusion, or synthesis, is the process of combining two or more distinct entities into a new whole. Fusion may also refer to: Science and technology Physics *Nuclear fusion, multiple atomic nuclei combining to form one or more different atomic nucl ...

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. Docking and attachment systems allow the user to simulate docking with a

space station A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station i ...

or other spacecraft, and rendezvous with and retrieval of

satellites A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotop ...

. Users can also build

s in orbit. The Solar System as presented in ''Orbiter'' consists of the

Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...

, the eight

planet A planet is a large, rounded astronomical body that is neither a star nor its remnant. The best available theory of planet formation is the nebular hypothesis, which posits that an interstellar cloud collapses out of a nebula to create a you ...

s and their major

moons A natural satellite is, in the most common usage, an astronomical body that orbits a planet, dwarf planet, or small Solar System body (or sometimes another natural satellite). Natural satellites are often colloquially referred to as ''moons'' ...

. Many

dwarf planet A dwarf planet is a small planetary-mass object that is in direct orbit of the Sun, smaller than any of the eight classical planets but still a world in its own right. The prototypical dwarf planet is Pluto. The interest of dwarf planets to p ...

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

s (except Vesta), and

comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...

s not included in the simulator are available as add-ons. Although ''Orbiter'' contains a database of over 100,000 stars, these are for display purposes only and

interstellar travel Interstellar travel is the hypothetical travel of spacecraft from one star system, solitary star, or planetary system to another. Interstellar travel is expected to prove much more difficult than interplanetary spaceflight due to the vast dif ...

is currently not possible in the simulator. The simulator also includes a planetarium mode that allows

ecliptic The ecliptic or ecliptic plane is the orbital plane of the Earth around the Sun. From the perspective of an observer on Earth, the Sun's movement around the celestial sphere over the course of a year traces out a path along the ecliptic again ...

and

celestial Celestial may refer to: Science * Objects or events seen in the sky and the following astronomical terms: ** Astronomical object, a naturally occurring physical entity, association, or structure that exists in the observable universe ** Celest ...

grids to be overlaid onto the star map, along with labels of the

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The origins of the e ...

s and other celestial markers. 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. The traditional simulated control interface in ''Orbiter'' consists of two

multi-function display A multifunction display (MFD) is a small-screen ( CRT or LCD) surrounded by multiple soft keys (configurable buttons) that can be used to display information to the user in numerous configurable ways. MFDs originated in aviation, first in mil ...

s and a

head-up display A head-up display, or heads-up display, also known as a HUD (), is any transparent display that presents data without requiring users to look away from their usual viewpoints. The origin of the name stems from a pilot being able to view informa ...

. Each features several modes of operation, with all commands given via the

keyboard Keyboard may refer to: Text input * Keyboard, part of a typewriter * Computer keyboard ** Keyboard layout, the software control of computer keyboards and their mapping ** Keyboard technology, computer keyboard hardware and firmware Music * Musi ...

or mouse. The simulator also supports customized control panels and instruments, including 3-D virtual cockpits and 2-D instrument panels. 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 A cockpit or flight deck is the area, usually near the front of an aircraft or spacecraft, from which a Pilot in command, pilot controls the aircraft. The cockpit of an aircraft contains flight instruments on an instrument panel, and the ...

also allows the player to freely look around from the perspective of the pilot. Since ''Orbiter 2006 Patch 1'', it has supported

TrackIR TrackIR is an optical motion tracking game controller for Microsoft Windows created by NaturalPoint Inc.. TrackIR tracks head motions with up to six degrees of freedom (6DOF) in later models, allowing handsfree view control for improved game im ...

, which allows the simulator to track the head-movements of the player and adjust the view accordingly.

Realism

''Orbiter'' was developed as a

simulator A simulation is the imitation of the operation of a real-world process or system over time. Simulations require the use of models; the model represents the key characteristics or behaviors of the selected system or process, whereas the s ...

, with accurately modeled planetary motion,

gravitation In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stron ...

effects (including non-spherical gravity), free space, atmospheric flight and

orbital decay Orbital decay is a gradual decrease of the distance between two orbiting bodies at their closest approach (the periapsis) over many orbital periods. These orbiting bodies can be a planet and its satellite, a star and any object orbiting it, or ...

."Orbiter Technical Notes: Dynamic State Vector Propagation", Martin Schweiger, 2006P. Bretagnon and G. Francou
"Planetary theories in rectangular and spherical variables. VSOP87 solutions"
(PDF 840KB), Astronomy & Astrophysics 202 (1988) 309–315. The position of the planets in the solar system is calculated by the

VSOP87 The semi-analytic planetary theory VSOP (French: ''Variations Séculaires des Orbites Planétaires'') is a mathematical model describing long-term changes (secular variation) in the orbits of the planets Mercury to Neptune. The earliest modern scie ...

solution, while the Earth-Moon system is simulated by the ELP2000 model. Only n-body

Newtonian mechanics Newton's laws of motion are three basic laws of classical mechanics that describe the relationship between the motion of an object and the forces acting on it. These laws can be paraphrased as follows: # A body remains at rest, or in motion ...

are simulated, not taking

relativistic effects Relativistic quantum chemistry combines relativistic mechanics with quantum chemistry to calculate elemental properties and structure, especially for the heavier elements of the periodic table. A prominent example is an explanation for the color of ...

into account. This means that phenomena such as

time dilation In physics and relativity, time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them ( special relativistic "kinetic" time dilation) or to a difference in gravitational ...

due to

are not simulated. The default version of ''Orbiter'' has no sound, however popular add-ons called OrbiterSound and XRSound are available. Both of them provides 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 2016'', terrain elevation is modeled for Earth, the Moon, and Mars. Support was also added for higher definition surface textures and clouds.

Included spacecraft

''Orbiters standard distribution includes real and fictional spacecraft and space stations:

Real vessels

;: The ''Orbiter'' version of the Space Shuttle ''Atlantis'', a retired Space Shuttle orbiter formerly operated by

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

, and the only player-controllable spacecraft based on a real world design that is included with the basic installation of ''Orbiter''. ;

Space Station A space station is a spacecraft capable of supporting a human crew in orbit for an extended period of time, and is therefore a type of space habitat. It lacks major propulsion or landing systems. An orbital station or an orbital space station i ...

Mir ''Mir'' (russian: Мир, ; ) was a space station that operated in low Earth orbit from 1986 to 2001, operated by the Soviet Union and later by Russia. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to&n ...

'': ''Orbiters 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 The International Space Station (ISS) is the largest modular space station currently in low Earth orbit. It is a multinational collaborative project involving five participating space agencies: NASA (United States), Roscosmos (Russia), JAXA ...

: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 The Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versa ...

(HST): A model of the real HST, it gets used together with ''Orbiters Space Shuttle ''Atlantis''. ;

Long Duration Exposure Facility NASA's Long Duration Exposure Facility, or LDEF (pronounced "eldef"), was a school bus-sized cylindrical facility designed to provide long-term experimental data on the outer space environment and its effects on space systems, materials, operatio ...

(LDEF) Satellite: Like the Hubble Space Telescope, it's one of the example payloads for ''Orbiters Space Shuttle.

Fictional vessels

;Delta-Glider (DG): A

delta wing A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (Δ). Although long studied, it did not find significant applications until the Jet Age, when it proved suitabl ...

spaceplane A spaceplane is a vehicle that can fly and glide like an aircraft in Earth's atmosphere and maneuver like a spacecraft in outer space. To do so, spaceplanes must incorporate features of both aircraft and spacecraft. Orbital spaceplanes ten ...

, 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 A scramjet (supersonic combustion ramjet) is a variant of a ramjet airbreathing jet engine in which combustion takes place in supersonic airflow. As in ramjets, a scramjet relies on high vehicle speed to compress the incoming air forcefully ...

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 A single-stage-to-orbit (SSTO) vehicle reaches orbit from the surface of a body using only propellants and fluids and without expending tanks, engines, or other major hardware. The term usually, but not exclusively, refers to reusable vehicles ...

spaceplane. ;Shuttle-A: A small space freighter, which can transport six large cargo containers with a total mass of . 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 ''Space Tug'' is a young adult science fiction novel by author Murray Leinster. It was published in 1953 by Shasta Publishers in an edition of 5,000 copies. It is the second novel in the author's Joe Kenmore series. Groff Conklin gave it a mixe ...

for the construction of

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 ''Orbiters 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''. It consists of a wheel, attached to a central hub with two spokes. The wheel has a diameter of and is spinning at a frequency of one cycle per 36 seconds, providing its occupants with a

centrifugal acceleration In Newtonian mechanics, the centrifugal force is an inertial force (also called a "fictitious" or "pseudo" force) that appears to act on all objects when viewed in a rotating frame of reference. It is directed away from an axis which is parallel ...

of . ;Carina: A small fictional science satellite, which is used as payload on ''Orbiters 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 The Ariane 4 was a European expendable space launch system, developed by the ''Centre national d'études spatiales'' (CNES), the French space agency, for the European Space Agency (ESA). It was manufactured by ArianeGroup and marketed by Arian ...

, which later resulted in the ARD.

''Orbiter'' add-ons

An extensive

API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standa ...

enables ''Orbiter'' users to contribute by creating add-ons. Many spacecraft are available for download as add-ons, ranging from the

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

Vostok spacecraft Vostok (russian: Восток, translated as "East") was a class of single-pilot crewed spacecraft built by the Soviet Union. The first human spaceflight was accomplished with Vostok 1 on April 12, 1961, by Soviet cosmonaut Yuri Gagarin. The V ...

to Apollo program. 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. Add-ons are also available for new surface bases, MFD modes, extensions of the simulation menu, space stations, planets, and even other planetary systems. Since ''Orbiter 2006'', a scenario editor is included, which can also be extended for supporting the special attributes of add-on vessels. A third party modlist installer by orbiter-mods.com called Orb can be used to automatically install mod bundles.

References

External links

Official websiteOrbiter: Manual
- current manual for ''Orbiter''
Orbiter-forumOfficial wikiOfficial add-on repository
- all add-ons from Orbit-hangar have been moved here.
orbiter-mods
- an open source mods repo featuring mod bundles and an automated modlist installer called Orb
Review: Orbiter space flight simulator
o
Techhaze interview with creator Martin Schweiger
{{DEFAULTSORT:Orbiter (Simulator) 2000 video games Open-source video games Windows games Windows-only games Video games developed in the United Kingdom Space flight simulator games Lua (programming language)-scripted video games Freeware games Realistic space simulators