A better title for “Lost in Space” would be “Mired in Mediocrity.”

Updating the 1960s series for the Netflix age was a good idea, but the execution is lacking in this new chronicle of the Robinson family’s spacefaring adventures. Once the drama gets past its first three episodes — which take too long to lay out a very simple series of premises — much of the action plays out, inevitably, in a forest outside Vancouver. Lots of sci-fi shows have similarly familiar and utilitarian settings, and far less money than this 10-episode drama, so they focus on creating meaty, surprising relationships and supplying vivid adventures.

“Lost in Space” has trouble doing those kinds of things on a consistent basis, nor does it successfully dabble in the light comedy of the original. As was the case with 2011’s “Terra Nova,” a very similar sci-fi chronicle set in a strange new world, those behind this version of “Lost in Space” seem to think that a genre show aimed at families must be as anodyne and blandly aspirational as possible. By contrast, “Doctor Who,” which debuted not long before the original “Lost in Space,” has run for more than five decades by assuming that its audience of children and adults will settle for nothing less than brisk plotting, heartbreaking moral dilemmas, very scary scenarios and complex characters whose cleverness and versatility is rarely in question.

“Lost in Space,” on the other hand, has trouble building interest in its characters or their challenges, in part because many members of the Robinson family are predictable, annoying or both. Set 30 years in the future, the Robinsons join a group of colonizers heading for new homes far from Earth, but things go awry very early in the pilot, and everyone is forced to improvise on a planet the settlers never expected to land on.

Molly Parker brings her usual verve, skill and charisma to the role of matriarch Maureen Robinson, and Parker Posey does what she can with the show’s underwritten and one-dimensional Dr. Smith. Many other key performances on the show are either underwhelming or poorly served with treacly, contrived dialogue. Posey and Parker, by far the most interesting cast members, are rarely served well by the writing.

The array of characters begins to expand beyond the Robinson clan fairly early on, but, like the sneaky Dr. Smith, Don West starts out as a relatively irritating presence and doesn’t progress much from there. Attempts to delve into problems in the marriage between Maureen and John Robinson sputter, given that John is a standard issue TV father with nothing unique to recommend him.

After five episodes of frequently slack pacing, meandering character development and derivative adventures, the only truly intriguing character around is the Robot, who, unlike a number of other “Lost in Space” characters, rarely does anything dumb. He also isn’t saddled with any painful exposition; his only line is the iconic, “Danger, Will Robinson!” The design of the very tall robot gives him a somewhat fearsome, spiky body, but the intimidation factor is offset by the Robot’s face, which looks a little like a lit-up snow globe that’s been shaken vigorously. Elements of imagination and mystery are locked inside the Robot — whose past and agenda remain unknown — and it’s those qualities that the rest of the show could use more of.

Instead, viewers are often subjected to characters making rash or stupid decisions, mainly because the plot requires them to do so. This undercuts one of the show’s core ideas, which is that the Robinsons, whatever their personal flaws, are all brave, savvy and intelligent. The adults, teen daughters and young Will do occasionally come up with smart schemes or face things that are genuinely terrifying. But one has to slog through a lot of clunky, simplistic storytelling to get to those moments. The earnestness of “Lost in Space” is admirable, but the fact that it feels like a mish-mash of a dozen other shows is consistently frustrating.

It’s true that many sci-fi series, including various incarnations of “Star Trek,” have had rocky first seasons and underwhelming characters at the outset. But the space programs that eventually earned their places in the TV pantheon offered something compelling early on — wit, winning romances, thoughtful moral dilemmas, visual daring, etc. Perhaps by the end of their first season of adventures on a distant planet, the Robinsons and their fellow survivors will have built lives, homes and relationships worth latching on to. But with so many of TV classics available now for streaming, it’s easy to wonder how many viewers will stick around to see what fates await the explorers at the end of these 10 installments.