Spatial Portal Alternatives

Celestia is an application for real-time 3D visualization of space, with a detailed model of the solar system, over 100,000 stars, more than 10,000 galaxies, and an extension mechanism for adding more objects.

Space Engine - a real-time 3D space simulator, procedural universe generator and visualiser. It lets you explore the universe in three dimensions, starting from planet Earth to the most distant galaxies.

Universe Sandbox is an interactive space simulator for Windows based PCs.

Unlike most astronomy software that just shows you what the sky looks like or where the planets are, Universe Sandbox is a powerful gravity simulator. You can add another star to our solar system and watch.

The Digital Universe Atlas incorporates data from dozens of organizations worldwide to create the most complete and accurate 3-D atlas of the Universe from the local solar neighbourhood out to the edge of the observable Universe.

Pioneer is a space adventure game set in the Milky Way galaxy at the turn of the 31st century. The game is open-ended, and you are free to explore the millions of star systems in the game. You can land on planets, slingshot past gas giants, and burn yourself to a crisp flying...

Cosmonium is a 3D astronomy and space exploration program. With Cosmonium you can navigate in our solar system and discover all the planets and their moons.

Orbiter is a realistic 3D real-time space flight simulator program.

Fed up with space games that insult your intelligence and violate every law of physics? Orbiter is a simulator that gives you an idea what space flight really feels like - today and in the not so distant future.

Mitaka is software for visualizing the known Universe with up-to-date observational data and theoretical models. Mitaka users can seamlessly navigate through space, from the Earth to the edges of the known Universe.

A game of missions, trade and space combat in the 31st century using the Pioneer Space Sim engine with many additions and improvements.

Gravity and space simulator that allows you to learn about the gravitational force and explore and learn about space. Change the value of the gravitational constant, increase the mass of Jupiter to see how doing so would affect the solar system and much, much more!

Space Simulator is a realistic space flight simulator for iOS and Android. It is an open-ended simulation where players can free roam Solar System or reenact historical NASA space program missions.

Reentry is a space flight simulator based on real life spacecrafts. You create a new astronaut, gain levels and experience for every move you make by completing missions in space.