Since sound waves do not propagate in vacuums such as space?

There is no sound.

Sound is a function of energy being transferred through the air, if in a vacuum then no energy is transferred.

Its like asking how do you make a splash when not in the water, you cant you need water to make a splash, and you need air to make a sound, without it nothing is happening.

Now what does happen?

Lest say 2 objects collide in space.

When they collide the energy of the collision will either be absorbed or transferred into a spark, broken pieces, or simply exchanged with each other. There is not medium like air to transfer to.

Well, ..., Space is not a perfect vacuum. The particle density varies but on average is ~10^3 particles per cm^3 (sometimes more sometimes less) versus the average density on earth of 10^9 particles per cm^3. As a result, some energy can propagate through the near vacuum of space. Moreover, by monitoring ultrasonic vibrations on a star (such as our Sun) we can use that ultrasonic vibration to peer through the star and see sunspots on the other side. This used to be a daily feature on www.spaceweather.com but NASA a since stopped using it. (See first link below)

Additionally, research has recently appeared indicating that sound waves from the big bang are detectable in the way the Galactic Super Clusters have been shaped. (See 2nd, 3rd, and 4th links below)

If you think about hitting a large cast iron bell in a vacuum, then the energy that would normally go into radiating the sound would instead manifest itself in some other way e.g. the bell would vibrate longer than it would in an atmosphere, where a lot of the energy 'leaks' as sound.

I'm not an expert per se, but I believe I know the answer.

Due to Newton Law's we know that whatever particles that are in motion would simply stay in motion. Whatever energy was moving said matter into the vacuum would continue onward. Kind of like air hockey, the puck has nothing to stop it so it just keeps going. But then of course if something enters it is no longer a vaccum. The astronaut and all that wonderful atmosphere stays near us because their are greater forces counter acting it.

You have to remember that energy is sort of a concept. It is tied deeply to the way matter interacts with it.