Simulating Human Space Missions

The European Concordia Station in Antarctica hosted several ESA doctors and scientists during this past winter. Their aim is to gain an understanding of the physiological and psychological effects of long-term confinement and isolation of small human groups—a project promoted as important and necessary to prepare for the day when humans will journey to Mars and undertake other long-duration missions in space.

Articles describing these efforts could leave readers thinking that hazardous, isolated long-duration voyages were a new and unknown form of human activity. A typical narrative will emphasize how the crew is “trapped” in an alien and hostile environment and forced to “get along” with their crewmates while trying to remain alert, functioning and sane—imagining that no immediate help, or pre-arranged escape to safety, is possible. People working in a setting where the menacing threat of death is constantly present is very dramatic. But do we really know so little about human endurance in these situations that current Earth simulations are relevant research for future mission to the planets?

We already possess an extensive database on people who’ve been isolated in small groups for months at a time. People have undertaken long voyages of isolation with emotionally intense small-group dynamics for years—for example, at sea in the age of sail. Sometimes, these voyages ended poorly; lurid tales of mutiny, murder, madness and cannibalism fill the sensational literature of that era and indeed, extend into our own time. Although some exploratory trips were epic and truly heroic, the vast majority were conducted without serious dislocations to the crew and have expanded humanity’s knowledge and wealth manyfold.

Within this treasure trove of information about human survival and the health of small groups during long periods of isolation, a particularly useful data set comes from crew experiences on nuclear missile submarines, the “boomers” that make up one leg of our strategic nuclear “triad.” Boomer crews go out on patrol for periods of 70-90 days duration, a somewhat shorter time than the typical outbound Mars mission (which depending on the opportunity, would last more than twice as long) but longer than a human lunar expedition. A submarine crew is completely isolated during a patrol; they must function together effectively and are interdependent upon each other for survival. Many aspects of submarine life are similar in both concept and technology to space flight, including group isolation, life-support, and the need to function in an extreme environment under high-pressure circumstances. The experience base of nuclear subs extends back over 50 years and we are highly conversant with its requirements and pitfalls.

Yet, some aspects of long-duration spaceflight—critical areas intrinsic to the space environment, such as the hard radiation exposure of a trip to Mars—are not fully understood, and no matter how carefully planned, cannot be properly addressed with any simulation. Although the absence of gravity can be mitigated (via in-flight countermeasures) or eliminated (by spinning the spacecraft to create artificial gravity), hard radiation must be blocked. This requires a significant amount of mass for shielding, which introduces the obvious problem of accelerating the now heavier vehicle to the same escape velocity to go to Mars, and that added mass takes more energy for departure—requiring an interplanetary spacecraft that is bigger (and thus more expensive) to build and fly. Many nations are actively planning human missions to land and work on the Moon. The experience base of using local resources to withstand the hard radiation of the lunar surface will directly contribute to developing similar protection for future planetary missions.

Some space analog “simulations” put small groups into a remote and potentially hostile locale to conduct exploration and research. The NASA Haughton-Mars project established a base camp in the Canadian arctic near the 23-kilometer-diameter Haughton impact crater. This crater formed about 40 million years ago. It is a relatively intact, complex impact structure with a central uplift similar to the complex craters with central peaks seen on planetary surfaces. As such, it potentially has much to teach us about the impact process. It has been studied extensively by “non-space simulating” geologists, who have provided a host of data on the formation of large craters.

Have recent efforts to simulate the isolation of future Mars exploration here on Earth added to our knowledge? More specifically, what have these efforts taught us about exploring planetary surfaces that we didn’t know already from the experience of the Apollo missions (now almost 50 years in the past) and long-duration submarine patrols? Apollo astronauts—under strict training regimens for their Moon flights—conducted field simulations in order to learn geology and become proficient in how to use tools in the field (some tools were created to address range of motion limitations of their spacesuits). Most Apollo astronauts had the benefit of military experience and thus understood factors important for their survival, such as preparation, teamwork and working under pressure within a chain of command.

One could argue that the current generation of astronauts has no direct experience in planetary surface exploration and that these “analog” exercises bring that field experience home. But the people engaged in these exercises are not scheduled for flight (human flights to Mars are decades away) and thus, their personal experiences are irrelevant. It has been argued that by knowing help is not immediately available, participants have the incentive to quickly find the right solution to a problem—in other words, taking a significant risk with one’s life focuses the mind more readily than what is possible for the armchair explorer. One is reminded of Samuel Johnson’s comment about mortality, “Depend upon it, sir, when a man knows he is to be hanged in a fortnight, it concentrates his mind wonderfully.”

Many of these space mission “analogs” appear to be more about gratifying the needs and wishes of their participants than they are about paving the way for future human exploration of space. An analog activity should have relevance to some unknown or under-appreciated aspect of long-duration human spaceflight, such as closing the life-support loop or protecting the crew from hard cosmic radiation. One simulation that does have such value for future missions is the long-running Desert RATS program of the NASA Johnson Space Center. This effort comprises a series of field exercises designed to understand the needs and possibilities of using people and machines—working together—to conduct field geology. In a manner similar to how the Apollo crews were trained to conduct geology on the Moon, the program seeks to understand exactly what is required to achieve a specified level of understanding for future planetary surface missions: what kinds of data are needed, how much characterization of a field site is enough, and the optimum levels of sampling and documentation.

To make significant progress in preparing for future planetary exploration, we must understand what factors are still unknown, which need more study, and what has already been discovered (existing knowledge). Suiting up and walking across some quasi-alien landscape on Earth doesn’t prepare you for Mars. However, by conceiving and undertaking a methodical, systematic research program, while cognizant of existing data (coupled to defined program objectives), you can prepare to address the remaining unknowns.

Paul D. Spudis | READ MORE

Paul D. Spudis (1952-2018) was a senior staff scientist at the Lunar and Planetary Institute in Houston, Texas, and a prolific author on the subject of the moon. His books include The Value of the Moon: How to Explore, Live, and Prosper in Space Using the Moon's Resources.