Dear Stormworkers,

In this weeks announcement post, we discuss some of the new systems, and explain what to expect in the upcoming Space DLC, with regard to the mechanics of orbit and travelling to the Moon.

Stormworks Space DLC releases on the 12th October.

https://store.steampowered.com/app/2383250/

As previously discussed, space in Stormworks will not be a true planetary body simulation. There are apparent limitations - the moon is in a fixed position directly above in the sky, and the world is a wrapping grid rather than a spherical wrapping one.

So, Stormworks: Space is just a new moon island high in the sky then? Well, no, and there are some cool new systems which model gravity, orbits, and planetary bodies which results in a simulation that appears to observe many of the rules and effects of physics found in planetary body simulations:

Gravity

Gravity in Stormworks: Space is derived from the distance to the earth and moon. The pull of gravity fades with distance with a physically accurate equation.

Elliptical Orbits

As the earth rotates, there is a centrifugal effect - objects would travel in a straight line except for the effect of gravity accelerating their path towards the centre of the earth, and thus curving their path. This acceleration due to gravity is constant. Motion in the horizontal plane is actually moving away from the centre of the earth very slightly, and as this horizontal motion increases, the acceleration away from the centre of the earth increases. This acts in the opposite direction to gravity.

The vertical acceleration due to horizontal motion is inversely proportional to the distance from the centre of the earth, so as you travel higher, there is less acceleration. This effect introduces elliptical orbits. To achieve a circular orbit, of constant altitude, you must have equal force due to gravity and horizontal velocity, and also have zero vertical velocity, at the same time.

Planetary Body Rotation

The earth rotates one revolution every day. As you launch from the surface, you launch with the horizontal velocity due to this rotation. This also means that to remain at a fixed position above the ground, you must also be travelling horizontally so that one revolution is also made every day. At around 300km above the surface of the earth, this velocity balances out the effect of gravity, achieving geostationary orbit.

Navigation

We are adding a new astronomy sensor that provides coordinates that better explain your location in space. The area between the earth and moon is mapped. Some navigation type sensors don't work in space such as GPS, which will stop working at a certain altitude, similar to the real world. The coordinate systems provided by the astronomy sensor are much more useful for understanding your position relative to the earth and moon.

As discussed, we are introducing world-wrapping at the same time as the Space DLC releases, meaning travelling across the edge of the map will wrap you back around on both the earth and the moon. This applies to quite a high altitude, but as you get deeper into space, the world will no longer wrap and you can travel infinitely.

We can't wait to share this new update! We look forward to your thoughts and feedback on these new systems.

Much love <3,

The Stormworks Developers