What was God's purpose in creating the world, creating us, and creating the space that the world exists in? There is no doubt that God created everything we see around us, and even the things we cannot see, he created them all. Colossians 1:16 says, "For everything, absolutely everything, above and below, visible and invisible...everything got started in him and finds its purpose in him." God also created human beings in his image, and sent us out into all the world making disciples of all nations. But God also has another purpose for humans, as can be seen in Revelation 4:11b which says, "You created everything, and it is for your pleasure that they exist and were created!" God takes pleasure in us, and he takes pleasure in his creation. On the seventh day, he surveyed all that he had created and said "it is good." If God says his creation is good, and takes pleasure in it, then it is the truth.
It is our (human beings) interaction with that creation that is called the cultural mandate.
The cultural mandate is God's call for us in Genesis 1:28, to "Be fruitful and multiply, and fill the earth and subdue it." The early writers of the Bible never conceived that some time in the future human beings would have the capabilities to explore space in any way or form. In the same sense, the early writers did not even imagine the existence of living entities smaller than a speck of dust on the molecular level. Therefore, the study of God's creation is like looking through a scope. This scope can be a telescope or a microscope but either way, as humankind has developed so has technology and with it the capabilities to study creation on many vast new levels.