Learning new words through Topic studies

This term we have been learning about space. I have made a very deliberate effort to choose texts and transcripts that have language which is cutting edge for the students ( neither too hard nor too easy). This means they come across lots of new words and phrases when reading listening or viewing texts. It has now become a regular practice for them to notice these new words and write them down for future references.
So each child has their own vocabulary book in which they write down all the new words learnt during reading or researching time. They use words from the vocabulary book when writing their stories. Till now we have had more than 100+ plus word in our book.
I have to make sure I provide more and more opportunities where students can use these words as many times as possible so they become a part of their everyday use.