It’s a book written by Robert Heinlein – if you ignore his central individualist message in the book it’s an entertaining read. And I’d dearly love to see this one get made into a movie.
You see a mathematics professor develops a device to translate through six spatial coordinates. So X,Y,Z,t, tau, teh and another. The t of course is time. So not only space but time – two of my favorites.
But I suspect it’s the very title of the book that puts people off from creating a screenplay from it. They’d rather go with Starship Troopers, another Heinlein book.
Spewing Truth in the face of Lies 
I am presently reading (for the first time) stranger in a strange land.
Ah Stranger in a Strange Land is one of my absolute favorites. The Fosterites are scary as all hell too. I’d love to see a screenplay for this one, the still religious would blow their tops.
My opinion of it has changed over the years. When it first came out I read it and sat there for a long time wondering what the hell I’d just read and how I felt, frankly, cheated, like I was the victim of a con artist. I thought it was the worst thing he’d ever written. My opinion has moderated somewhat over the years. I still don’t like it, but I do now see the satire, the anagrams, the in jokes and other things going on it. Still, it would make one hell of a fun movie with modern special effects technology. I’d pay to go see it. The one I’d really like to see made into a movie is The Roads Must Roll. And maybe The Glory Road.