Clement’s later novels included females because people had pointed out to him that his novels had no females in them. To be fair, his work is not ardently sexist; it was just often focused on a group of scientists going to an alien planet to study the aliens ... and at the time Clement was writing, "group of scientists" largely meant "group of male scientists". There are female characters in “Iceworld”, and also in “Needle”, but those are set on Earth (with the aliens visiting us), where a complete absence of female characters would be a bit glaring. I think 'Needle' would be an interesting book to make a film from ... and (spoiler alert) given that the aliens are just amorphous blobs that live inside the body of a human host, it wouldn't be that expensive to make. If it had been the point of the book, a space-mission with fewer than 40% female crew would have been a different story and, concomitantly, much longer if added to the voyage to Mesklin.
If you're into SF, read on.