Updated: Sep 17, 2022
Video from C.S. Lewis Institute
"Dr. David C. Downing, co-director of the Marion E. Wade Center at Wheaton College, leads this discussion on The Space Trilogy by C.S. Lewis. This video is from A Book Observed, a C.S. Lewis book club, presented by the C.S. Lewis Institute. The book club presents discussion and teachings on a number of books by Lewis. The C.S. Lewis Institute (CSLI) is a nonprofit organization designed to develop disciples who will articulate, defend, share, and live their faith in Christ in personal and public life. If you would like more info about the Institute, visit our website at www.cslewisinstitute.org/events_page Info on the C.S. Lewis Fellows Program can be found at www.cslewisinstitute.org/Fellows_Program " from video introduction.
For all of you who have never read The Space Trilogy by C.S. Lewis perhaps its time!
I read these many years ago, maybe in the 1980's but have not made my way back until now. Retired so some time to go back in my reading. There is a lot out there now about theses books so I present some of it to you now. The book by Dr. David Downing is an excellent book to have in your library: The Most Reluctant Convert: C. S. Lewis' Journey to Faith (link). - Andy
Trilogy History & Description
In 2014 The Space Trilogy was 75 years old. Today that makes it 82 years old! This post from the C.S. Lewis Website in 2014 gives us an excellent summation of all three novels.
"To mark the 75th anniversary of C. S. Lewis’s classic Space Trilogy, featuring the adventures of Dr. Ransom on Mars, Venus and Earth, a special omnibus ebook has been released. This ebook includes an exclusive Foreword compiled from letters by J.R.R. Tolkien, who inspired Lewis to write the first volume and on whom the main character of Ransom was largely based. The Space Trilogy is a remarkable work of fantasy, demonstrating the powerful imagination of C.S. Lewis. Readers and fans can revisit all three books in the trilogy:
OUT OF THE SILENT PLANET Dr. Ransom, a Cambridge academic, is abducted and taken on a spaceship to the red planet of Malacandra, which he knows as Mars. His captors are plotting to plunder the planet’s treasures and offer Ransom as a sacrifice to the creatures who live there…
PERELANDRA Having escaped from Mars, Dr. Ransom is called to the paradise planet of Perelandra, or Venus. When his old enemy also arrives and is taken over by the forces of evil, Ransom finds himself in a desperate struggle to save the innocence of this Eden-like world…
THAT HIDEOUS STRENGTH Investigating the truth about her prophetic dreams, Jane Studdock encounters the fabled Dr. Ransom, who is in great pain after his travels. A sinister society run by his old adversaries intends to harness the ancient powers of a resurrected Merlin in their ambition to subjugate the people of Earth…
The Space Trilogy (LINK)
It All Began with a Challenge!
"Hoping to prove successful in combining a love of things old with mythology and with a desire to uphold the dignity of the human person in a world rent asunder by warring ideologies, J.R.R. Tolkien and C.S. Lewis challenged each other to create deep works of the imagination. After a “toss up,” the two men agreed that Lewis’ stories would deal with space travel while Tolkien’s would deal with time travel.
“Tollers,” C.S. Lewis declared, using one of the many names—nicked as well as given—of his good friend, John Ronald Reuel Tolkien. “There is too little of what we really like in stories. I am afraid we shall have to try and write some ourselves.” 
Though Tolkien did not record the exact date of this conversation, it almost certainly happened sometime in the mid-1930s, and, as Christopher Tolkien has argued, probably in 1936. Tolkien had already written but had not published The Hobbit, and he would soon write, if he had not already, his most famous academic essays on Beowulf and on faerie stories. He also held one of the most prestigious chairs in all of the University of Oxford, the Merton Chair at Merton College. Lewis, however, held the much less prestigious position of “Fellow” at Magdalen College, Oxford, but his writing career was at nearly the same stage as Tolkien’s. By the mid 1930s, he had written his first significant piece of scholarship, “A Note on Comus,” as well as Allegory of Love, but after his conversation on Christianity in September and October of 1931, he had also begun to write Christian apologetics in a variety of forms. The first significant such book was his Pilgrim’s Regress, after which, “he never looked back, but appeared to my dazzled eyes to go on for the rest of his life writing more and more successful books at shorter and shorter intervals.” He also, importantly, began to challenge prominent, well-established intellectuals and debate with scholars well beyond his circle of friends and intimates, such as classicist and rising star, E.M.W. Tillyard..." from the article: The Challenge: How C.S. Lewis’ Space Trilogy Came Into Being