PHOTO COURTESY NETFLIX

It’s remarkable that filmmakers try to make sad space movies as often as they do.

The microgenre, which concerns lonely astronauts and explorers undergoing journeys of the soul while simultaneously stumbling around the cosmos, can lead to some very good results — such as Denis Villeneuve’s masterful “Arrival” and Christopher Nolan’s underrated “Interstellar.” It can also lead to forgettable, plodding misfires.

Which brings us to “Spaceman.”

Directed by “Chernobyl” helmer Johan Renck and based on a well-regarded novel by Jaroslav Kalfař, “Spaceman” stars Adam Sandler as Jakub, an astrophysicist on an impossibly long journey. A mysterious particle cloud has turned up in the vicinity of Jupiter, and Jakub is sent on a years-long journey to see what’s floating around up there.

Meanwhile, his wife (Carey Mulligan) is thinking of leaving him, increasingly embittered that Jakub agreed to float through the solar system during her pregnancy. Amid uncertainty both cosmic and domestic, Jakub starts to break down.

Then a giant, soft-spoken spider with a human mouth shows up.

Does that sound silly? Because it’s pretty silly. While some forgiving viewers may accept the presence of Hanuš, an ancient floating arachnid voiced by Paul Dano, more will likely chuckle at the beastie’s searching eyes and unsettling molars. Over the course of a very long hour, Hanuš helps Jakub unpack his feelings while teasing secrets from the beginning of time.

Curiously, the film does arrive at an effective conclusion — but only if you ignore the dull events that precede it. While Sandler, in his serviceable sad-sack mode, approaches the material earnestly, the pieces never come together.

Sad space movies are all indebted to a pair of masterpieces: Kubrick’s “2001: A Space Odyssey” and Tarkovsky’s “Solaris.” Those are pillars of filmmaking made by some of the most gifted (and, it must be said, reckless) directors in history — and what’s more, they are unconventional works that succeed in spite of their atypical structures. Attempting to imitate them is risky business; it can be done successfully, but it requires a combination of incredible luck and remarkable skill.

“Spaceman,” while not without merit, lacks both.

My Rating: 4/10

“Spaceman” begins streaming March 1 on Netflix.