I read Out of the Silent Planet, by Lewis. It's certainly of its time (1930's) and is an old solar system adventure. What it really is though, is Lewis using the background of planetary adventure to spin his brand of 'aren't we a deplorable species' concerns, along with clunky Christian philosophy. It may well have been fine when written, and of course Lewis writes very well, but its message is rather childishly presented in my opinion. Not sure I would recommend it particularly, unless you have an essay to write on early Christian SF. I like the cover very much though, and while it's not essential reading, it's neither long nor boring so for those interested, I suppose it's a C+ effort, no worse.