Cady Coleman, in space, talking to her son in Space: The Longest Goodbye (Cady Coleman/Greenwich Entertainment)

Which do you think is scarier, the bottom of the ocean, or outer space? This is a common question these days on numerous online discussion boards, and the general consensus seems to be, the ocean. This is perhaps because it is closer to us and demonstrably full of strange things (creatures, ruptures in the Earth’s core) that we are still discovering. Space (planets, asteroids, and all) might seem like a bit of a blank slate in contrast. Yet the new documentary Space: The Longest Goodbye, while it does not address fear per se, takes as its subject the many difficulties of spending a long time in outer space. The National Aeronautics and Space Administration is planning on sending astronauts to Mars at some point in the next decade, and the expedition is expected to last three years. Those who are leaving must be prepared.

Dr. Al Holland, a NASA psychologist, guides us through this process and details the many psychological challenges that astronauts face. He is joined by various astronauts and their families, as well as experts who are developing ways to help the Mars-bound explorers cope with their journey. These interviews are skillfully set against footage of astronauts floating through the space station and news clips and still photographs. All of the above makes the difficulties of these endeavors quite clear: long-term isolation from one’s family, frustration with fellow crew members, too much time in one’s head, struggles adjusting back to life upon return.

If the introductory section feels a little obvious, the film picks up steam as soon as Holland begins analyzing the techniques he has used to help families deal with a loved one in space. This is, in large part, because these passages are exceptionally moving. Interviews with astronaut Cady Coleman and her son, Jaimy Simpson, as well as footage of their video chats, speak powerfully to the basic need for connection and how it can be attended to even while one’s mother floats in outer space, while containing all the challenges of any mother-son relationship. In one particularly poignant scene, she addresses Jaimy over the camera for being rude to his grandmother. They both know the reason: He misses his mother. Details like these are abundant in the interviews conducted and in Holland’s own testimony.

Real-time video communication will not be possible for those headed to Mars, and how best to serve these explorers remains an open-ended question. The latter-half explores the various answers that have been posed, and they reveal both the scrupulousness of those proposing solutions and the blunt reality that they are all preparing for something unknown. There are tests to see how well a crew can work together; VR technology to communicate with loved ones even with a time lapse; an AI companion named Cimon to keep crew members company; and even a scientist working to see if it is possible to make humans sleep for the duration of travel, as they have in so many sci-fi movies. I will say it was hard to imagine both VR and AI being anything but frustrating in space. Then again, isolation on a spaceship is something that comparatively few people have experienced. Each expert does an excellent job outlining the remedies their solutions are intended to address while remaining open about the fact that this expedition is high-risk and will contain many surprises.

What might be missing from the documentary, informative and moving though it is, is the allure of living in space, although one astronaut remarks that, when she’s in space, everything she’s doing is important. Nevertheless, toward the end, when Coleman says that, she further states that if she’d had the opportunity to extend her time in space by another six months, she’d do it no question, which comes as a bit of a shock. Where was this sentiment earlier? Though the shock may have been intentional, it still signals an area left unexplored. And might it be psychologically illuminating to get more of a sense of how astronauts are fighting to balance a sense of isolation with a genuine engagement with their work? The excitement of space is more or less assumed here, yet these are minor quibbles with a documentary that does much to inform the viewer of the unromantic aspects of the final frontier.