Universe Sandbox ² - Third Stage Saturn V

The new model for the third stage of the Saturn V rocket.

We’re still working hard to get Alpha 19 polished and ready to go. We hope to have it ready in the next few weeks.

Until then, you can read about what’s coming in Alpha 19 below and try out a preview version by manually opting in via Steam:

  1. Right-click on the game title in your Steam Library
  2. Click on ‘Properties’
  3. Select the ‘Betas’ tab
  4. Set the dropdown menu to ‘alpha19preview
  5. Close the Properties window
  6. Steam will now update Universe Sandbox ² to the preview version
  7. Once updated, launch Universe Sandbox ²


1. Roche Limit & Tidal Heating

In this simulation, the Moon is orbiting Earth within the Roche limit and is being torn apart by tidal forces.

In this simulation, the Moon is orbiting Earth within the Roche limit and is being torn apart by tidal forces.

When a small celestial body approaches a larger body at a distance inside its Roche limit, it begins to stretch and disintegrate due to tidal forces. Essentially, the gravitational force acting on the closer side of the smaller body is stronger than the force acting on the far side. Outside of the Roche limit, these tidal forces are still present and can heat bodies in close orbits.

In Universe Sandbox ² Alpha 19, you can see these effects when a satellite tightly orbits its primary body, or when a star gets too close to a massive black hole, or even if two identically-sized bodies are in a close binary orbit. First, the secondary body will heat up, then if it’s close enough, it will begin to disintegrate and lose mass by producing a stream of particles. Often times these particles will begin orbiting and form a nice glowing ring around the primary body.


2. Models for Saturn V 3rd Stage, New Horizons probe, & Police Box

Universe Sandbox ² - Updated New Horizons Model

We’ve put in improved models for the third stage of the Saturn V rocket, which was used in multiple lunar missions, and the New Horizons probe, which has famously given us a closer look at Pluto. We’ve also added in another very important spacecraft, the police box.  These new and improved models were made for Universe Sandbox ² by Toby Halter, who is continuing to make models for us. It’s not possible to pilot or control these spacecraft… but we’re talking about it.

To check these out, you can load up the following sims:
– Third Stage of the Apollo 12 in Orbit of Earth in 2003
– New Horizons Pluto Encounter in 2015

Or you can place them in any simulation: Add > Objects tab.


3. Improved Explosion Power

Universe Sandbox ² - Earth Moons Explode

We’ve improved both the visuals and the simulated effects for the explosion power.

As you can see in the screenshot above, using Explode on a body will send out a “shock wave” which will affect surrounding bodies as well, causing a chain of destruction. Realistic destruction, of course.


4. Simulation Quality Setting

You can now adjust a Simulation Quality setting in Home>Settings>General tab. This will adjust the maximum number of attracting and non-attracting bodies, which in turn will affect the number of particles/fragments produced and how long they last. Set it to “Auto” to determine the best settings for your hardware.

In the future we hope to have this setting adjust dynamically with what is happening in the simulation, in order to constantly find the best balance between performance and simulation experience.



We still have some bugs to sort through and some polish to add, so hold tight. We’ll let everyone know once Alpha 19 is available.

The laser, which is already part of the VR mode, is still being integrated with the additional surface detail feature. We expect these features to be ready for Alpha 20.

You can buy Universe Sandbox ² on our website or on the Steam Store.

Follow us on Twitter and Facebook for the latest Universe Sandbox ² news.