Every kids love coloring pages and you can give them with space coloring pages if they want it. You can download it in the website. There are many websites provide you about this coloring pages. Just make sure your kids love the themes.
You can download it and that means you have no worry about payment. There are websites provide you about free coloring pages, especially for space coloring pages.
This becomes great choice since there are many cartoons talk about space, your kids may love space coloring pages too. They will accept it as gift from you. Then, find them more.