For custom features goto the custom branch here: https://github.com/racerx2/orbiter2027-Linux/tree/Custom

Orbiter 2027 Space Flight Simulator — native Linux port+

Orbiter is a spaceflight simulator based on Newtonian mechanics. Its playground is our solar system with many of its major bodies – the sun, planets and moons. You take control of a spacecraft – either historic, hypothetical, or purely science fiction. Orbiter is unlike most commercial computer games with a space theme – there are no predefined missions to complete (except the ones you set yourself), no aliens to destroy and no goods to trade. Instead, you will get a pretty good idea about what is involved in real space flight – how to plan an ascent into orbit, how to rendezvous with a space station, or how to fly to another planet. It is more difficult, but also more of a challenge. Some people get hooked, others get bored. Finding out for yourself is easy – simply give it a try. Orbiter is free, so you don’t need to invest more than a bit of your spare time.

This tree is the Linux-only code of a line-by-line port of orbitersim/orbiter (commits in UPSTREAM, via racerx2/orbiter-2027-Linux) to native Linux: no Wine, no DXVK, graphics on Vulkan 1.3, windows and dialogs on Qt 6, sound on PipeWire. Orbiter itself holds no Windows code; the one Windows part is the optional Wine bridge that runs old Windows add-ons. Orbiter for Windows is orbitersim/orbiter.

Why fly this one

• Fly anywhere on Earth. The whole planet streams in as you fly: real imagery and terrain, 3D cities, roads and rivers, and real airports with their runways painted on and lit up at night. No texture packs, no accounts.
• Land on the real Mars. Valles Marineris, Olympus Mons and Jezero stream in from USGS maps, down to 6 m detail.
• Navigate like a pilot. A GPS comes with it: moving map, flight plans, 80,000 airports and beacons, glide paths and GPS steering, on any ship.
• Keep your Windows add-ons. Ships, MFDs and plugins made for Orbiter 2010, 2016 and 2024 fly from their zips, through Wine, with nothing to set up.
• Crash like it matters. Hulls dent, tear and break into debris; buildings take the hit too.
• Build in Blender. glTF ships with every PBR material, and a round trip to Blender and back with the animations.
• See it properly. Shadows, reflections, volumetric plumes, re-entry plasma, valley fog and cities lit street by street.
• Fly your own pit. Any key or function on any stick, throttle, pedal set or button box; windows on any monitor.
• Native and portable. Vulkan, Qt 6 and PipeWire. One download runs on Ubuntu, Mint, Debian, Fedora, Arch, SteamOS and more.

What's new since the Windows version

The whole Earth, streamed

New York, Paris, Chicago and London, streamed in while flying.

Take off anywhere and fly over the real thing. Earth streams in as you fly, from free servers with no account or key:

• Imagery and terrain for the whole planet: Sentinel-2 imagery, elevation, water and coastlines.
• 3D cities: buildings from OpenStreetMap wherever it has them, set on the terrain with textured walls and roofs and windows lit at night. With the Collision module on they are solid: ships crash into them and can land on their roofs.
• Roads, railways, airports and rivers from OpenStreetMap, painted on the ground, with street lamps where the city is lit at night (below).
• Ground detail: 3D trees from land cover out to the horizon, terrain shadows, volumetric clouds without tile seams.
• Ahead of you: the ground, buildings and roads under the next minute of your flight path load before you get there.
• Offline: download a region ahead of time under Options > Planet streaming, buildings and roads included.

Sources, settings and credits: Earth imagery.

Real airports, day and night

Houston Hobby by day, and on final at night. Nothing here was modelled by hand.

Every airport OpenStreetMap knows is there, streamed with the ground around it:

• Runways as pilots see them: their numbers, threshold bars, touchdown zones, aiming points and centre lines, the taxiways and aprons around them, and the hangars and terminals.
• Lit at night like a real field: white edge lights turning yellow near the end, centre line, green thresholds, red ends, touchdown zone and approach lights.
• PAPI on the left of each end: two white and two red on a 3° glide path.
• Ready on the runway: a scenario's landed ships wait for the finest ground under them, so they stand on the runway from the first frame, not above or under it.

Mars, streamed

A Delta-glider on the rim of Coprates Chasma, Valles Marineris.

Mars streams the same way, from USGS's public maps: natural-colour imagery, 6 m CTX detail along the equator and MOLA terrain. Land in Valles Marineris, on Olympus Mons or at Jezero. The old Mars texture pack is retired.

A GPS in every cockpit

The GPS navigator with a flight plan from Hobby to Bush Intercontinental, Houston.

It comes with Orbiter: turn on GPSNav in the Launchpad's Modules tab and click the GPS pin on the menu bar. A panel GPS unit for any ship on any planet or moon, laid out like the real thing:

• Moving map with the terrain in colour, airports, runways, beacons, Orbiter's bases and pads, north up or track up.
• Direct-To, flight plans and Nearest: plans are saved with the scenario; the nearest airports, bases and beacons are a button away, with their runways, frequencies and elevations.
• Approach: a glide path to any runway or pad, a course needle, and GPS roll steering (GPSS) that banks the ship to follow the plan.
• On the HUD: a magenta caret on the heading tape points to the active waypoint.
• Data: about 80,000 airports and beacons and 35,000 runways on Earth from OurAirports, every base on every body, and your own airports and waypoints in simple CSV files (GPSNav/User).

The manual is the unit's help button. Source: Src/Plugin/GPSNav.

More planets and moons

Pluto, with its thin nitrogen atmosphere and blue haze, and Charon.

• The Pluto system: Pluto, Charon, Nix, Hydra, Kerberos and Styx, which Orbiter never had.
• New ephemeris modules for Phobos, Deimos, Miranda, Ariel, Umbriel, Titania, Oberon and Triton (Windows has them only as 32-bit binaries), and better orbits for Hyperion, Proteus, Nereid and Vesta.
• Spin axes and prime meridians from the IAU rotation model.
• Every planet and moon on the tile renderer, with new maps for Mercury, Saturn, Uranus, Triton, Pluto and Charon. The textures are a separate download (Orbiter-linux-orbital-bodies-textures); the Launchpad offers to download and install the missing ones.
• Measured atmospheres for every body that has one, so drag and aerobraking use real densities.
• SPICE ephemerides: the planets and moons from JPL's kernels (Orbiter's new SPICE module, with Kerberos and Styx added). The Launchpad downloads the kernels; until then the built-in modules are used.

Launchpad skins

Change how the Launchpad looks without changing what it does. Pick a skin under Extra > Launchpad skin:

• Dark: a dark style sheet for the classic Launchpad.
• Horizon (above) and Planetary Defense: complete new launchers, made as Qt Designer forms.
• Your own: copy a skin, or make a new layout of the stock Launchpad, and edit it in Qt Designer. See Skins/README.md.

Ctrl+Shift+L always brings back the classic Launchpad.

Your Windows add-ons still fly

BaseSync MFD 3.3, built for Orbiter 2016 on Windows, running in the Delta-glider's left MFD.

Older add-ons from the Orbiter 2010 days, such as UCGO and UMmu, now load too, all through Wine.

Two decades of Orbiter add-ons are Windows .dll modules. They load here too, through Wine:

• No setup: install the add-on as on Windows, by extracting its zip into Orbiter. Where Orbiter finds a Windows module and no Linux one of that name, it opens it through the Wine bridge.
• What works: ships with their 2D panels, virtual cockpits and HUDs, MFDs, plugins with their dialogs, planets and atmospheres, Launchpad items, camera modes, Lua methods, and the add-ons' sounds through XRSound (OrbiterSound calls too). BaseSync MFD and Launch MFD, for example, run as on Windows.
• Needs Wine with 32-bit support (on Linux Mint: Software Manager, Wine). 32-bit add-ons only for now.
• Add-ons that add bases to a planet bring their own part in Config/<Planet>.d/, so extracting one zip over another never undoes it.

How it works: Src/WineBridge.

Fly your own pit

A throttle, a stick and rudder pedals, each named, calibrated and bound, right in the Launchpad.

Every key and every function can be bound to any controller: joysticks, throttles, rudder pedals, button boxes, the keyboard and the mouse. Under Options > Controllers, in the Launchpad or in flight:

• Bind by pressing the button, moving the axis or pressing the key, for every ship or for one ship class.
• Rename and calibrate each controller; set the dead zone and the throttle saturation; reset to the defaults.
• Plug and play: controllers are found as they are plugged in; a new setup binds the first stick.
• <Disabled> has Orbiter ignore every controller.

Every monitor

Multiple displays: one view of the Moon across three monitors.

An MFD and the Scenario Editor dragged out onto a second monitor and resized there, leaving the first monitor to the view.

• Full screen opens on the Launchpad's monitor. Multiple displays spans all monitors (X11, and KDE Plasma on Wayland).
• In-flight windows (external MFDs, the map, dialogs) drag out of the render window onto other monitors and stay on top.

Solid ground

Ships sit, roll and taxi like ships:

• Nothing goes into the terrain: wheels stand on the ground at rest, landed ships settle on slopes, and a hull that touches down rests on its own shape.
• Ships hold on slopes: the ground pushes along its real slope, and friction holds a parked ship.
• Taxiing: nosewheel steering works (the Delta-glider with its gear down, from the yaw keys, stick or pedals), and the nose wheel swivels at taxi speed, so the brakes alone turn the ship too.
• Hard landings at any time acceleration: stiff ground contacts get the substeps they need.

Collisions and damage

Ships finally hit things.

Two Delta Gliders hit head-on at 70 m/s in orbit.

An add-on that makes ships collide with each other, with base buildings and with the ground:

• Colliders follow each ship's real mesh, so cargo bays stay open.
• Docked and attached stacks respond as one body, and every impact conserves momentum.
• Hulls dent, crush and tear where they hit, sized by the crash energy.
• Structures break apart live in the simulation with NVIDIA Blast, on the CPU (no special graphics card needed). Pieces that come off fly away as debris.
• Crashes into buildings and into the ground do the same damage.
• The streamed 3D buildings are solid too, with the shape they are drawn with: ships crash into them and can land on their roofs.
• Damage and debris are saved with the scenario and play back in flight recordings.
• A ship that absorbs more than 1 kJ per kg is destroyed: it loses thrust, and the player loses its controls (keys, joystick, cockpit switches); its MFDs can still be switched with the Shift keys.
• High-speed crashes don't freeze the game, even when a breakup makes dozens of pieces.
• Autopilots can ask the add-on whether a path is clear (Developer Manual, Clearance queries).

Turn it on in the Launchpad's Modules tab (Collision). Settings are in Config/Collision.cfg.

glTF ships and a Blender round trip, animations included

A Delta Glider exported from Blender as a .glb, with PBR materials, next to the stock Delta Glider (GL-01).

The stock Delta-glider, exported from Orbiter and opened in Blender: its animations come along as Blender actions, posed here with the nosecone, ladder, top hatch, radiator and gear open.

Ships no longer have to be converted to Orbiter's .msh format, and any ship can go to Blender and come back:

• To Blender, animations included: the GltfExport add-on (Tools/GltfExport) writes any vessel, stock or add-on, as one .glb: meshes, materials, textures, and every animation as a Blender action with its hinges and keyframes.
• Back into Orbiter: edit it in Blender (export with Include > Custom Properties ticked) and drop the .glb in the vessel's mesh folder, for example Meshes\DG. Orbiter uses it in place of the .msh meshes it was made from, outside and cockpit, keeping the part, material and texture numbers the vessel's program uses. What you left alone stays exactly as before; what you changed (shapes, new parts, hinges, keyframes, colours, painted images) comes from the file, animations included. Remove the file to go back.
• New ships straight from Blender: export glTF Binary (.glb, +Y Up on) or .gltf, put it in a folder under Meshes and name it in the vessel's cfg, for example MeshName = MyShip\myship.glb. A .glb carries its textures inside, so there is no converter, no texture folder and no material file to write. In Blender the nose points along +Y and the top along +Z.
• Every glTF PBR material feature: base colour and alpha (opaque, cut-out, transparent), metallic and roughness, normal maps, emission with strength, ambient occlusion, IOR and specular, transmission and volume (tinted glass), clearcoat (car paint), sheen (fabric), anisotropy (brushed metal) and iridescence (thin-film colours).
• Lit by the simulation: the sun with shadows, the ship's own lights, and reflections of its surroundings.
• Glass seen through glass: a HUD behind the canopy, a visor inside a helmet, or another ship's windows behind your own show through, tinted by the glass in front.
• Old models unchanged: .msh meshes look exactly as before. They can get PBR materials too, through PBR lines in their Config/GC material file.
• Collisions: with the collision add-on, glTF ships collide on their real shape.

Not supported yet: skeletons, morph targets, a second UV set, texture transforms, Draco or KTX2 compression, and animations in a .glb named directly in a cfg (a vessel's program makes its animations; the round trip above keeps them).

Try it with the Delta-glider > DG and DG-S and DGTest scenario, and Graphics > PBR material bench, which shows every material on its own sphere.

Graphics effects

Re-entry plasma and hull heating; valley fog in the Alps; shadows and sea reflections; Atlantis' plume.

New in the Vulkan client, each a switch in Modules/VulkanClient/VulkanClient.cfg (on by default, fog off):

• Shadows (SceneShadows): sun shadows of ships, buildings and terrain out to about 40 km from the camera.
• Reflections (SSR): water and glossy hulls reflect the scene around them.
• Bounce light (SSGI): sunlit ground and hulls light up what is next to them.
• Plumes and smoke (VolPlumes): lit volumetric exhaust with shock diamonds, ground clouds and smoke.
• Re-entry (VolPlumes): a plasma sheath shaped by the hull, and a hull that heats up and glows from the nose and leading edges, then cools slowly. Works for any ship, no add-on changes needed.
• Fog (HeightFog): fog that fills valleys and lies over the sea, by time of day and season.
• Night look (NightLook): cities lit by street lamps that light the ground, building windows that come on at dusk, and nights that stay dark.
• Orbiter's flame or the plume, per ship: ExhaustStyle = legacy or volumetric in a vessel's cfg, so an add-on keeps the exhaust its maker drew.

How they work: the Technical Reference (Vulkan effects). For add-on makers: the Developer Manual (Graphics content).

Multiplayer

Under construction – stay tuned.

License

Orbiter is now published as an Open Source project under the MIT License (see LICENSE file for details).

The graphics engine (OVP/VulkanClient, ported from D3D9Client) is dual licensed under GPL v3 and LGPL v3, see GPL and LGPL.

Installation

Hardware requirements needed by Orbiter:

	Minimum requirements	Recommended requirements
RAM:	500 MB	2 GB
CPU:	Dual Core
GPU:	Vulkan 1.3	Vulkan 1.3
Disk:	5 GB of free space	10 GB of free space (80 GB if you want hi-res textures)

The Vulkan driver also needs the extensions listed in COMPILE.md.

Download a build

Ready-to-run builds for 64-bit PCs are on the Releases page (Orbiter2027-Linux-x86_64-<version>.tar.xz). One download runs on Ubuntu 22.04 or newer (and Linux Mint, Pop!_OS, Zorin OS), Debian 12 or newer, Fedora 36 or newer, RHEL / AlmaLinux / Rocky Linux 9 or newer, openSUSE Tumbleweed, Arch Linux, Manjaro and SteamOS. Unpack it into a folder you own and start OpenOrbiter; it checks the few system libraries Orbiter uses and offers to install any that are missing. Qt and the other libraries that differ between distributions come with the download. How it is built: packaging/linux.

Build from source

Get the port repository from github

git clone -b Custom https://github.com/racerx2/orbiter2027-Linux.git

To configure and build you need CMake 3.28 or later, Ninja and GCC with C++20. See COMPILE.md for details on building Orbiter.

Planet textures

The Orbiter git repository does not include most of the planetary texture files required for running Orbiter. You need to install those separately. The easiest way to do so is by installing an Orbiter release. Optionally you can also install high-resolution versions of the textures from the Orbiter website. You should keep the Orbiter installation separate from your Orbiter git repository.

To configure Orbiter to use the texture installation, set the ORBITER_PLANET_TEXTURE_INSTALL_DIR entry in CMake. For example, if Orbiter was installed in ~/Orbiter, the CMake option should be set to ~/Orbiter/Textures.

This path can also be set using ORBITER_PLANET_TEXTURE_INSTALL_DIR environment variable

Alternatively, you can configure the texture directory after building Orbiter by setting the PlanetTexDir entry in Orbiter.cfg.

Earth imagery

Earth is not part of the texture download. While Orbiter runs, the tiles it draws stream in from free servers that need no account or key, and are kept in Textures/Earth like installed tiles. The sources are listed in Config/TileStream.cfg; with the shipped file the requests go to:

• tiles.maps.eox.at: surface imagery, EOX Sentinel-2 cloudless 2016, levels 1 to 16
• gibs.earthdata.nasa.gov: night lights (NASA Black Marble 2016), the OpenStreetMap water mask, and NASA Blue Marble standing in at levels 10 and below while EOX does not answer
• esa-worldcover.s3.eu-central-1.amazonaws.com: ESA WorldCover 2021, the 10 m water mask and the land classes for the ground detail, from level 12
• s3.amazonaws.com (elevation-tiles-prod): elevation, Terrain Tiles on AWS
• eoimages.gsfc.nasa.gov: clouds, the NASA Visible Earth cloud map (levels 1 to 7)
• tiles.openfreemap.org: 3D buildings out to the building range (20 km by default, 5 to 40 km in the VulkanClient's advanced setup) below 15 km altitude, nearest first; past about 4 km only those tall enough to show. They are set on the terrain with textured walls, roofs and lit windows at night; the textures are drawn by the build itself (Utils/bldgtex, into Textures/Bldg), and a building inside a base's own buildings is left out; from the same tiles, the roads, railways, airports and rivers painted on the ground

The runways and pads of the Earth surface bases are laid flat at the base's height. Elevation below sea level is raised to 0 m except in the FLOOR boxes of Config/TileStream.cfg (the Dead Sea, the Caspian Sea, Death Valley, the Qattara Depression and other large depressions); the Netherlands polders stay at 0 m.

An Orbiter 2016 Earth pack installed in Textures/Earth/Archive is still used for its imagery, masks and clouds. Its elevation, which includes trees and buildings, is replaced with streaming on: a tile takes the streamed heights once the stream has the elevation of its parent tile, and shows them the next time it is loaded. Nothing has to be deleted for this.

Orbiter.cfg keys:

• TileStream (default TRUE): stream Earth tiles
• TileStreamOffline (default FALSE): no requests, only tiles on disk
• TileStreamCacheMB (default 2048, 0 no limit): at the start of a session and every five minutes the tiles used longest ago go first; levels 8 and below are always kept
• TileStreamBuildings (default TRUE): stream 3D buildings
• TileStreamWays (default TRUE): stream roads, railways, airports and rivers

The Launchpad page Options > Planet streaming sets the first three, shows the cache size, clears the streamed tiles (only files the stream wrote, listed in Textures/Earth/TileStream) and downloads a region ahead of time around a base or a position, for flying offline. A region download is refused while Offline is ticked or while the tiles are being cleared.

The VulkanClient draws 3D trees from the streamed land cover where it shows forest or shrub, below 3 km above the ground. With the terrain horizon shadows, ambient occlusion, volumetric clouds and auto exposure they are the Ground graphics group of the VulkanClient Advanced Setup dialog; VulkanClient.cfg keys (defaults): HorizonShadows (1), SSAO (1), SSAOStrength (0.8), SSAORadius (1.5 m), VolClouds (1), VolCloudQuality (1, 0 low to 2 high), Trees (1), TreeRange (2500 m), TreeDensity (1), AutoExposure (1), AutoExpMinEV (-1.5), AutoExpMaxEV (2.5), CloudAtlas (1, cloud layer without tile seams).

The Effects group of the same dialog switches the look passes, each on its own; VulkanClient.cfg keys (defaults): LensFlare (1), LightShafts (1), TAA (1, temporal anti-aliasing), WaterFx (1, waves, glitter, sky reflection, foam), VolCloudShadows (1, shadows of the volumetric clouds), Filmic (0, filmic tone curve), Vignette (1), Sharpen (1), HeatHaze (1, shimmer behind engines), and in its third row SceneShadows (1, sun shadows of terrain, buildings, trees and vessels), SSR (1, reflections of the scene in water, runways and glossy hulls), VolPlumes (1, volumetric engine plumes, lit smoke, soft particle trails, re-entry plasma and hulls glowing from re-entry heating), SSGI (1, one bounce of light from nearby surfaces), SSGIStrength (1.0, 0 to 2), HeightFog (0, valley fog and haze layers), NightLook (1, street lamps, lit windows and a darker night exposure).

Privacy: each tile request tells the server which part of Earth is shown. Its only headers are Host, User-Agent: OrbiterLinux/<version>, Accept-Language: en, Accept-Encoding and Connection, and Range for a WorldCover read; no cookies are kept or sent. Offline mode makes no requests.

Earth credits

The same credits are on the Launchpad page Options > Planet streaming, from Config/TileStream.cfg, and in the user manual's Credits section.

• Imagery: EOxCloudless https://cloudless.eox.at by EOX IT Services GmbH (Contains modified Copernicus Sentinel data 2016 & 2017), CC BY 4.0
• Imagery where EOX does not answer: NASA Blue Marble: Next Generation (NASA Earth Observatory, Reto Stöckli), via NASA GIBS
• Night lights: NASA Black Marble 2016 (VIIRS), via NASA GIBS https://www.earthdata.nasa.gov/gibs, part of NASA's Earth Science Data and Information System (ESDIS)
• Water mask: © OpenStreetMap contributors, available under the Open Database License https://www.openstreetmap.org/copyright, via NASA GIBS
• Water and land cover: © ESA WorldCover project 2021 / Contains modified Copernicus Sentinel data (2021) processed by ESA WorldCover consortium, CC BY 4.0 https://esa-worldcover.org
• Clouds: NASA Visible Earth, Blue Marble clouds (NASA Goddard Space Flight Center, Reto Stöckli) https://visibleearth.nasa.gov
• Elevation: Terrain Tiles on AWS https://registry.opendata.aws/terrain-tiles: Mapzen
  • ArcticDEM terrain data DEM(s) were created from DigitalGlobe, Inc., imagery and funded under National Science Foundation awards 1043681, 1559691, and 1542736
  • Australia terrain data © Commonwealth of Australia (Geoscience Australia) 2017
  • Austria terrain data © offene Daten Österreichs – Digitales Geländemodell (DGM) Österreich
  • Canada terrain data contains information licensed under the Open Government Licence – Canada
  • Europe terrain data produced using Copernicus data and information funded by the European Union - EU-DEM layers
  • Global ETOPO1 terrain data U.S. National Oceanic and Atmospheric Administration
  • Mexico terrain data source: INEGI, Continental relief, 2016
  • New Zealand terrain data Copyright 2011 Crown copyright (c) Land Information New Zealand and the New Zealand Government (All rights reserved)
  • Norway terrain data © Kartverket
  • United Kingdom terrain data © Environment Agency copyright and/or database right 2015. All rights reserved
  • United States 3DEP (formerly NED) and global GMTED2010 and SRTM terrain data courtesy of the U.S. Geological Survey.
• Buildings, roads, railways, airports and rivers: © OpenMapTiles https://openmaptiles.org © OpenStreetMap contributors, available under the Open Database License https://www.openstreetmap.org/copyright, served by OpenFreeMap https://openfreemap.org

Mars imagery

Mars streams the same way, from USGS Astrogeology (public domain): the MDIM 2.1 colour mosaic, the CTX controlled equatorial mosaics (Robbins et al. 2023) and MOLA elevation. The tiles are kept in Textures/Mars; the old Mars pack is no longer offered. Every streamed body's cache and credits are on the Launchpad page Options > Planet streaming.

Help

Help files are located in the Doc subfolder (if you built them with -DORBITER_MAKE_DOC=ON). Orbiter User Manual (Linux).pdf is the main Orbiter user manual.

The in-game help system can be opened via the "Help" button on the Orbiter Launchpad dialog, or with Alt-F1 while running Orbiter.

Remaining questions can be posted on my Discord.