Is there any movie based on Robert Heinlein's work? If so, is there more than one?
Starship Troopers was VERY loosely based on his book by the same title. That's the only one I know of. It's a terrible adaptation, as well.
There was also an animated miniseries made of Red Planet.
There's also Roughnecks: Starship Troopers Chronicles, and while not great is better than the Starship Troopers movie (though oddly enough, Wikipedia claims this show was based on both the original book & that awful movie).
It's got to be doubtful if it would ever get made, but there's a screenplay for Moon Is A Harsh Mistress here
The low budget StarQuest: Beyond The Rising Moon, reedited and upgraded as Outerworld is adapted from Friday, though only various parts, names, actions and the planet Halcyon were used. Shot entirely in a D.C. warehouse, and using miniatures, it has the look of cheap, but it's quite good, and addictive. I recommend it as an um-(sort of)Friday.
Not sure whether this counts, but there's a short video of "And He Built A Crooked House".
To the best of my knowledge (And I've been an SF and film buff for decades) the listings above are all the Heinlein stuff which as been adapted.
You could nominally add "The Trouble With Tribbles" as being inspired by it. David Gerrold was purportedly unaware of any connection until long after the fact, but even he acked that the resemblance between Tribbles and RAH's "Flatcats" from The Rolling Stones is awfully close. RAH was contacted before its production by Paramount's legal dept. and signed off on the usage as acceptable to him.
I'd also note the similarity between Star Trek's Operation: Annihilate! with RAH's "The Puppet Masters".
I do disagree with the complaints about Starship Troopers. It's not a particularly close adaptation (Verhoeven really did NOT understand the culture RAH was writing about, as shown by the obviously Nazi-esque uniforms for the Intel Officers) but it's not an awful movie itself, and the book is remarkably didactic and Verhoeven did a fairly good job of getting a lot of that subtle material into the movie with the "internet 'Want to know more?'" elements -- which at the time was perceived as the future of the internet (i.e., "push" content vs "pull" content -- As usual, the commercial interests Got It Wrong. One reason why government-directed technology never works, and central-planning schemes always go awry. It's impossible to reliably predict the direction a billion people will trend things)
In other words, if you look at it as "based on" ST rather than an actual adaptation, then it's not awful.
Stranger in a Strange Land
Has been picked up for a TV series for SyFy (source)
Not sure how well that's going to go, personally.
The controversial elements, and true driving forces of the novel, are religion and sex, which Heinlein’s publisher at the time wanted him to cut out. But as the author noted to his literary agent, if religion and sex were removed from the text, what remained would be the equivalent of a “non-alcoholic martini.”
I know this strictly isn't a movie but thought that Heinlein fans might have a passing interest.