To explore and understand our universe cannot diminish it- it only enriches our ability to appreciate it. I for one hope the future will regard Clive Staples Lewis as a dogmatic, small-minded fool.
For Lewis, science is not evil, but it can be used to dehumanize, especially when people focus solely on the scientific and throw out or de-emphasize all other aspects of human existence. Anyone who cannot see some measure of dehumanization in the modern world is blind. I see huge changes just during my life. When I was a child, we knew the names of at least 20 families within a block of our house, and had been in the home or had had in our home at least half of them. Now, most people have much less knowledge or contact with their neighbors, and that isolation is greater for those who benefit the most from the fruits of modern technology.
If Lewis had lived to see the moon landing, I think he would have admitted it was an awesome achievement. I certainly think it was. It was a defining moment in my childhood (I was 6 years old). However, if you compare the pre-modern conception of the moon with how we see it today, it has been reduced from a heavenly body to a large rock in space. This reduction is symptomatic of the reduction of our conception of our own humanity from spiritual beings loved by the creator of the universe to accidental products of random, blind, impersonal, physical interactions. The modern conception of man is a product of evolution that was probably a bad turn since we seem to be damaging the planet on which we arose.
If you think Lewis was dogmatic, I'm sure you must really think Tolkien was, since he was Roman Catholic, which is by definition dogmatic. (To be a faithful Catholic, you must believe the dogmas of the Church. Anglicans, which Lewis was, have no such requirements. In fact, I don't think the Church of England has anything they call a dogma, but I could be wrong.) I don't know if Tolkien said anything against space exploration, but he did have strong views against the headlong rush of scientific progress that had no regard on its effects on humanity or the environment. I think most people today can see that his environmental concerns were well founded, even if they don't see the deeper human impacts.