Building a Solar System Spaceship Propulsion Simulator in a Weekend

Some projects start as small curiosities and unexpectedly evolve into something far larger than planned. This one began with a simple idea: What if anyone could choose a propulsion method, pick a planet, and actually visualize how long it would take to fly across the Solar System? What followed was a marathon weekend of coding that resulted in a fully interactive 3D space-travel simulator powered by Next.js, Three.js, hi-resolution planetary textures, and real positional data derived from NASA sources.

Multiple propulsion methods can be selected, from real world, to hypothetical.

Follow your spaceship as it travels to the destination planet, speed up time at will.

Selective detailed info on celestial bodies from planets, dwarf planets, and moons.

With the help of an AI coding assistant handling structure, physics explanations, and code generation across multiple files, the project came together with surprising speed. But the true centerpiece of the experience is the simulator itself: a dynamic, accurate, and beautifully rendered Solar System where users can experiment with propulsion systems ranging from chemical rockets to hypothetical warp drives.

A Living, Moving Solar System Built with Real Data

The simulator creates a version of the Solar System that feels alive. Every planet and moon follows its proper orbital period, axial tilt, and rotation speed. The initial positions of major celestial bodies are built from NASA ephemeris data, which ensures that the system does not begin in a fictionalized alignment. Instead, the planets start exactly where they belong, sweeping along the correct orbital paths as time advances.

The 3D environment uses hi-resolution textures mapped onto planets and moons through Three.js. Earth shows recognizable continents. Jupiter’s storms swirl with depth. Saturn’s rings tilt gracefully. Even smaller moons and dwarf planets carry crisp surface features. Combined with physically based lighting and shadowing, the entire Solar System feels like a place you’re visiting rather than a diagram you’re studying.

Time acceleration adds a sense of motion: seasons flash by, moons spin through their cycles, and planets shift positions in ways that directly affect travel plans. Watching orbits play out makes the Solar System feel big, dynamic, and always changing.

A Propulsion Playground

The interactive heart of the app lies in its propulsion panel. Here, users choose the engine that will carry their spacecraft across the Solar System. Each propulsion type is modeled with its own travel time, acceleration, and theoretical top speed. These differences dramatically change the feel of every mission.

To make this concrete, the simulator includes:

Chemical Rockets, the workhorse of human spaceflight, accelerating at 30 m/s² and topping out near 17 km/s. They remain powerful, but when you attempt to travel beyond Mars, their limitations become obvious.
Ion Drives, the opposite in temperament, barely push with 0.09 mm/s² of thrust yet reach astonishing speeds over time thanks to their extreme efficiency.
Solar Sails, which rely on sunlight pressure rather than fuel, gaining speed slowly but with no propellant constraints.
Nuclear Thermal Rockets, heating hydrogen with a fission reactor to achieve twice the efficiency of chemical propulsion, offering meaningful cuts to travel times.
Antimatter-Catalyzed Propulsion, the theoretical powerhouse, achieving enormous velocities thanks to matter-antimatter annihilation. This turns what would normally be months into days.
Photonic Propulsion, a pure light-drive concept reaching near-light speed.
And finally, a purely theoretical Alcubierre Warp Drive, included not for realism but for conceptual fun, shrinking interplanetary trips down to instant jumps.

Each propulsion type displays its expected travel time under current planetary alignment. Chemical engines might require three months, while antimatter systems compress the trip into days, and photonic propulsion reaches near-relativistic speeds. Watching those numbers update as planets move adds a strategic element: the system becomes a sandbox for understanding how alignment, acceleration, and distance all interplay.

Choosing a Destination and Launch Window

After selecting propulsion, users choose a departure world and a destination. The app supports missions between planets, moons, dwarf planets, and even asteroid regions. Because everything moves continuously, each trip is unique. A mission from Earth to Saturn may be ideal in one moment and wildly inefficient in another. Shifting the in-app date changes the alignment of the Solar System, and with it the travel time.

This shifting geometry teaches an important lesson: interplanetary travel is not simply a matter of distance, but timing.

Flip and Burn: A Deep-Space Maneuver Brought to Life

One of the simulator’s most satisfying features is its flip-and-burn system. In deep space, constant-thrust spacecraft do not simply accelerate all the way to a planet. Instead, they accelerate for the first half of the journey, rotate 180 degrees, and decelerate for the remaining distance. Without this flip, they would fly past their target at impossible speeds.

The simulator executes this maneuver visually and mathematically. Halfway through the trip, the spacecraft rotates smoothly, engine trails reverse direction, and the speed curve begins dropping. The moment feels cinematic: a subtle dance between momentum and control.

This detail elevates the simulator beyond a simple distance calculator. It becomes a visualization of real mission behavior.

Immersive Camera Perspectives

Three separate camera modes tie the experience together. A wide orbital camera shows the spacecraft sweeping across the Solar System as planets drift along their paths. A chase camera sits behind the ship, letting the user watch engine trails flare against the emptiness of space. A cockpit-style camera offers a serene view of stars drifting past as the ship accelerates toward a distant world.

Each mode gives the journey a different personality. The orbital view explains the mission, the chase view dramatizes it, and the cockpit brings an element of quiet immersion.

How the Simulator Understands the Solar System

Behind the scenes, the simulator performs constant calculations to keep everything aligned and moving correctly. Every frame, the app updates each body's angular position based on its orbital period. Distances are measured between the spacecraft and the destination, which allows the propulsion models to compute velocity changes and estimate remaining travel time.

NASA positional data provided the initial phase angles, and the resulting movement feels grounded and realistic. Even though the scale of the Solar System is compressed to fit into an accessible browser experience, its behavior retains scientific fidelity.

This blend of hi-resolution textures, orbital data, Three.js rendering, and continuous physics updates gives the app its distinct feel. It is both a visual experience and a lightly educational one.

A Modern Development Workflow Behind It All

While the simulator stands proudly on its own, the development process deserves acknowledgment. Using an AI assistant capable of generating code, explaining algorithms, drafting file structures, and debugging complex physics allowed the project to move from concept to finished prototype in a single weekend. Plan mode, in particular, made it possible to outline each major system before a single component was written.

Next.js handled routing, performance optimization, and bundling. Three.js rendered the Solar System in real time. Hi-res textures added realism. NASA data anchored everything in reality. The AI assistant acted as a collaborator capable of jumping between roles: architect, debugger, orbital-mechanics explainer, and refactoring partner.

The result is a project that would have traditionally required a small team, but today can be built by a single creator with the right tools.