The collision ist fine in the viewport and when rendering individual images, but in the final render it is ignored, the particles just 'fall through'...
Have you enabled collision for the smoke spreader and the launch Pad?
Also, in the particles settings under cache, have you baked the particles, click Bake if not.
When rendering a single image you scrub through to the animation to the frame you want to render, so you are basically viewing the animation in the viewport, when rendering the complete animation you will need to have baked the particles to memory, because I think the collision only effects the particles in viewport not in rendering, so this is why we bake the position of the particles before rendering. Hope this helps.
Have a cookie and carry on. 👍