This big-screen Imax film by George Butler is technically a documentary–it’s about an historical event and has plenty of footage and interviews involving the people actually involved in it–but one in which a good deal of the most intriguing sequences are CGI simulations rather than the real thing. That’s pretty much inevitable given the subject–the NASA mission to land two robot rovers on Mars to search for evidence that might indicate whether life could once have existed on the Red Planet. Obviously neither Imax cameras–which are pretty large and unwieldy things–nor the human beings required to operate them could have accompanied the rovers to document their work. So instead authentic footage of the earthbound elements of the enterprise–the long and grueling years of design and testing, as well as the nerve-racking moments at mission control as operators waited to learn whether the probes had successfully landed and deployed after months of flight–and actual photographs of the planet sent back by the machines–are melded with animated sequences depicting how the rovers reached the Martian landscape, unwrapped their components and investigated the surface with their precision equipment.

The mixture of real and imaginative footage may cause some concern about the genuinely “documentary” character of “Roving Mars,” but that’s not likely to bother most viewers. To them it will be enough that the 40-minute film is not only well-made, but effectively celebrates what has to be considered one of the major scientific triumphs of recent years. As one of the small army of personnel led by engagingly enthusiastic Cornell professor Steve Squyres remarks, success of the project required a degree of precision equivalent to shooting a basketball from L.A. to New York City and having it swish through the net. Using interviews and footage of the group effort to get the program literally off the ground, Butler captures the difficulty the team faced and the exhilaration of their success.

When the spacecraft leaves the launch pad, of course, the movie switches to CGI mode to portray the stages of the actual flight to Mars, the descent into the Martian atmosphere, the highly-padded landing on the surface, and the operation of the rovers as they emerge from a cocoon-like state and gingerly roll about, collecting and analyzing rock samples. It helps here that the two devices are differentiated not only in terms of names–one is called Spirit and the other Opportunity–but in “personality” (rather like the little robot cameras that James Cameron employed so effectively in his Imax filming about investigating the wreckage of the Titanic). Obviously they don’t have the catchy personas of Disneyesque cartoon figures, but they become more than just machines rattling about, and the “dedication” anthropomorphically ascribed to them when they continue to operate beyond their expected shelf-life or (in one case) traverse considerable distances to locate the sorts of rocks their creators want them to assess, while not overstated, gives them an almost “human” touch.

The classiness of the film is enhanced by the fact that Paul Newman serves to introduce it and Philip Glass provides one of his insistently minimalist scores to complement the action. The result is a picture that probably isn’t as enthralling as its makers hoped, but is interesting enough to make for good, informative family entertainment.