Concordia
The glider cockpit in a banked turn, round instruments below a windscreen filled by a lattice tower and the city curving overhead.

Three ways to fly Concordia

Concordia is a place to fly as well as to walk. A hang glider over the city, a two-seat rocket racer outside the hull and the 64 m Earth shuttle all fly on the same physics the station is built on, in your browser, with no install.

Start with the glider · 3D

What the tags mean

120 kgthe glider with its pilot, on a 16 m² wingDesign value Challenge this
2,300 m/sthe racer's whole fuel budget, start to stopDesign value Challenge this
155 tthe shuttle on a ferry flight, 33 s to turn roundDesign value Challenge this
157 m/sspeed of the rotor floor the glider flies overEstablished physics

Each vehicle is a different lesson in the same physics. The glider flies in air that turns with the floor, so which way you point changes how much you weigh. The racer has no air at all, so every corner is paid for in propellant. The shuttle has the racer's physics at 56 times the mass, so it handles like a ship and plans its stops kilometres ahead.

Hang glider: flying inside a spinning city

Chase view of the electric hang glider flying past a lattice tower over the first rotor, with parks, lakes and the curving city.
Chase view over Tsiolkovsky, the first rotor, 220 m up. The floor curves up ahead and overhead, and the glider follows that curve, held on it by its wing.

Take off from a street in the Arbor quarter, climb over the rooftops and fly the length of a city that curls up into the sky on both sides. The floor turns at 157 m/s, and the air turns with it, so flying with the spin makes you heavier and flying against it makes you lighter. Climb to 2,200 m, fly backward at 18.8 m/s and your wing needs no lift at all. Established physics

The hang glider on its take-off run down a tree-lined street, houses on both sides and the city rising beyond.
The take-off run down the street: hold Space for power and it lifts off by itself.
The hang glider 300 m over the rotor floor, parks, lakes and towers spreading ahead and curving up on both sides.
300 m up. From here the rotor is a 5 km tube with the city on its inside, and you feel 1.07 g.

What to try:

Fly the glider · 3DStart in the airHow flying in a rotor works

Rocket racer: a race on a fuel budget

Chase view of the cream two-seat rocket racer flying beside the station's lattice hull truss in black space, its flight display below.
The racer at 120 m/s alongside the hull truss. With no drag there is no top speed: the tanks decide how fast a crew can fly the course.

The racer is a 2.7 t two-seat rocket that launches off its own dock on top of the spaceport and races through gates of four drone beacons along the hull. There is no air to turn against and no road to grip, so a turn is a burn sideways. Every crew gets the same 2,300 m/s of velocity change, and the cockpit tape shows, live, how much of it the remaining gates and the final stop will cost. Established physics

The rocket racer lifting off its launch table at the spaceport, gate rings floating ahead in black space.
Launch: the racer pushes up off its table on its belly thrusters and lights the engine 28 m above the deck. The rings are the gates.
The view from the racer cockpit: a bronze canopy bow framing the station hull, with speed and the delta-v tape below.
From the cockpit, past the bronze canopy bow: speed, the delta-v tape and what you can afford to spend on going faster.
The rocket racer close beside the hull truss while a red flare it struck drifts away to the right.
The red flare at the right was struck with F. Nothing pushes it, so it flies on in a straight line while you turn away.

What to try:

Fly the racer · 3DWhy each turn costs fuel

Concordia shuttle: a 64 m ship by hand

Chase view of the long white Concordia shuttle flying past the station's domed end cap against a field of stars.
The Concordia shuttle at 250 m/s past the station's domed end. On four engines it pulls 0.42 g, and a full turn takes 33 s.

The shuttle is the vehicle that carries passengers to the transfer station in Earth orbit, flown here empty with full tanks. It uses the racer's physics at 155 t, so everything takes longer: 4.5 km to stop from 100 m/s, most of it spent turning round. The HUD marks where you would come to rest if you braked now, and that marker is how you fly it. Established physics

The Concordia shuttle on its sled on the launch rail along the grey station hull, beneath a lattice tower.
The launch rail: a sled on the 14.7 km guideway along the hull throws the shuttle out at 100, 250 or 540 m/s.
The Concordia shuttle in flight with its solar arrays unfolded, a satellite and more panels nearby against black space.
Arrays out. F unfolds the solar arrays and radiators once you are clear of the station.

Two ways out:

Fly from the dock · 3DLaunch from the railThe real trip to Earth

At the dock or the rail, press B to launch. From anywhere in Space mode, B opens the vehicle picker: 1 for the racer, 2 for the shuttle at the dock, 3 for the shuttle on the rail.

Controls

The racer and the shuttle share one layout. The glider flies like a small aircraft. Press ? in the simulation for every key in every mode.

Key Glider Racer and shuttle
Mouse look around point the nose
W / S nose up / down burn / brake
A / D turn slide left / right
Space / C power up / down; hold Space on the road to take off slide up / down
Q / E rudder roll
Arrows nose (up is up) and turn pitch and yaw
Shift airbrakes, wheel brake double the turn rate
X space brake: turn round and stop
F flare racer: flare; shuttle: arrays
R drop the ball hold to relaunch
T assisted / manual assisted / manual
Y cockpit / chase view cockpit / chase view
B board or stow launch, or open the picker

On a phone or tablet the simulation shows a thumb stick and buttons for each vehicle instead.

How each one works

A hang glider in flight above the rotor floor, with the city and lakes curving up ahead and overhead.

Flying in a spinning world

Why flying backward fast enough makes your weight disappear, and where a dropped ball really goes.

Close rear view of the cream racer: two long tank pods, a bubble canopy with two crew and the engine burning orange above the hull.

Racing where there is no air

What a corner costs, why the tanks set the top speed and how the racer is built.

An ivory shuttle parked on the launch track beside blue edge lights, floodlight masts and a bay sign on the station hull.

Getting there from L5

The launcher, the five-day fall to Earth orbit and the skyhook that the shuttle hands its passengers to.

  • Flying in a spinning world Inside a rotor, the inward force needed for circular motion produces apparent weight.
  • Racing where there is no air Out past the hull there is no air to lean on and no road to grip. The racer can go as fast as it likes, but every change of direction burns propellant it cannot get back.
  • Getting there from L5 Concordia floats in the Earth-Moon L5 region, 384,400 km from Earth.
  • The spaceport Everyone who arrives from Earth or the Moon comes through the spaceport at the forward end.