Safe for our kind, that is. You know, two-legged Earthian kind, not those nasty six-legged critters.
Brilliant physicist Dr. Stevens is off on a fact-finding mission, to save the honor of the brave pilots of the space-liner Arcturus from the desk-jockeys' imprecations of imprecision - the nastiest insult in his super-scientific world. He and the pilots are right, of course, but that's cold consolation when marauders from the depths of space hack up their ship and drag it off, in obvious violation of salvage laws.
Stevens and his beloved escape to an isolated moon of Jupiter, which happens to Earth-like right down to wildlife that's pretty tasty, when cooked up right. There, the fond couple struggle to rebuild all of Western technology from the ground up, and struggle to maintain the chastity of their impromptu engagement - lots of cold showers all around, I guess. They do a fair job of both, while events progress on just about every other bit of planetary real estate around. After much zooming around between worlds, the bad guys are all vanquished, the good guys and gals get properly hitched, and the space pilots protect their manly honor.
Parts of "Spacehounds" date back to the early 1930s, 75 years ago as of this writing. The goofy anachronisms are half the fun here, based on Smith's odd inability to imagine any technology much different from his own. The dated social commentary is amusing, too, for example in his mention of a dozen-plus of the space-liner's female passengers getting married before their rescuers arrived. They obviously didn't marry each other, but it somehow appears that women marry but men don't.
The date of writing is closer to Jules Verne than to today's science fiction, but a good bit harder to take seriously. Well, being serious isn't all that much fun anyway. If you want a happy bit of heroic space-silliness, Doc Smith is the man to bring it to you.
//wiredweird