Sunday, December 16, 2012

Glaciers on Mars

A summary of research on areoglaciology in Hellas basin


for Portland State University Glacier Field Study, Fall 2012


The Viking spacecraft which orbited Mars in the 1970s revealed several massifs on the eastern slopes of Hellas basin. These massifs are surrounded by lobate debris aprons morphologically suggestive of gelifluction, indicating the presence of some quantity of subsurface water ice (Squyres, 1979). Further observations by the Mars Global Surveyor revealed a knobby terrain atop these aprons consistent with significant thermokarstic processes associated with glaciers (Pierce & Crown, 2003). These features prompted inquiry into the possibility of atmospheric conditions by which moisture might have been directed to this region, and climate simulations for high-obliquity periods of Mars’s past indicated that atmospheric moisture from the southern pole may have precipitated in eastern Hellas during narrow time periods of oblique summers. The Mars Reconnaissance Orbiter’s Shallow Subsurface Radar was used to analyse these features, and the radar data collected suggests massive subsurface glaciers beneath a thin layer of debris. These observations in Hellas unveiled a significant portion of the martian cryosphere and indicated other probable locations where martian ground ice might be found (Holt et al., 2008).

Initial observations of the east Hellas massifs’ lobate debris aprons came from Viking orbiter data which began being taken in 1976. These features were hypothesized even at that time to be likely candidate sites for subsurface water deposits (Squyres, 1979). More detailed observations became available from the Mars Global Surveyor, which began its observations in 1999. The massifs of east Hellas were identified as geometrically similar to those mountainous formations known on Earth to form glacial cirques where snowfall might accumulate and compact. Knobby terrain and evidence of postemplacement debris flow on these aprons indicate an ongoing process of thermokarstic degradation (Pierce & Crown, 2003). Though not related to melt processes which form marshy terrain as in terrestrial thermokarst, the knobs atop these lobate debris aprons could be the result of wasting behavior associated with the loss of ice near the surface to sublimation due to fluctuations in local temperature and pressure. However, while the Viking and Mars Global Surveyor orbiter findings were both sufficient to morphologically suggest that Hellas contained subsurface water, morphology alone cannot verify or disprove the presence of subsurface water. Before more detailed physical observations were made, a model was devised to explain the possibility of high water ice concentrations that might have led to glaciation in Hellas basin.

As any great volume of trapped water ice on Mars is likely a result of past climate behavior, historical climate simulations became invaluable tools in assessing moisture distribution and concentration hypotheses. Mars’s current spin-axis obliquity of 25.1o (Mutch, 1976) does not indicate a clear climatic cause for moisture to have accumulated in Hellas. The water cycle of Mars as it is currently understood involves an annual water cycle wherein a great mass of water is sublimed from one hemispheric pole during its summer and precipitated on the other. The Laboratoire de Météorologie Dynamique’s martian global climate model was used to simulate the conditions of prior epochs in order to find a climatic model for accumulation of moisture in Hellas. When periods of 45o obliquity were simulated with an annual water cycle similar to the present one, it emerged that periods of ~90 days during southern summer would have experienced an interruption in northward travel of sublimed southern polar moisture by a “midlatitude westward summer vortex” in all southern mid-latitudes excepting the eastern portion of Hellas basin. This would have resulted in a “stationary planetary wave” involving transport, condensation, and precipitation over the region on an annual basis in past martian epochs: a robust model for the origin of the hypothetical subsurface water under this part of Hellas (Forget, 2006).

With climatic simulations supportive of past moisture precipitation in the Hellas basin, its morphological features were perceived with greater weight in assessing the region as a potential glacial site. Relative crater densities reveal the lobate debris aprons to be the youngest features of the region. The shape of the lobate debris aprons on the east Hellas massifs suggest the presence of some viscosity-lowering agent, and craters superposed atop these lobate debris aprons possess wide central peaks and moat-shaped borders, which indicate that they most likely formed in a substrate rich in water ice. On the basis of morphology and surface topology, it was estimated that between 10% and 50% of the interior composition of the lobate debris aprons could be comprised of water (Holt, 2008). These physical observations and their supporting climatic  models were still insufficient to verify or discount the presence of water, however. The physical properties of these features required more subtle analysis.

Thus, the Mars Reconnaissance Orbiter’s team recruited its shallow radar to scan for reflectors beneath the surface of these lobate debris aprons. Strong radar reflection signals would indicate a predominantly rocky composition beneath the lobate debris aprons, while less reflection could be interpreted to indicate a water-rich makeup. These scans did not produce the volume scattering patterns that would indicate a majority composition of reflective rocky material. In fact, those reflection signals which were produced appeared to originate either from well beneath the features, or from debris at their bases. The radar signal attenuated at a rate of about 10 decibels per kilometer, which is consistent with attenuation by water ice. The attenuation interpretation was checked by using the known velocity of electromagnetic waves through water ice to convert the time-delay radar data to a depth graph. The resultant depth model matched the time delay model very closely. All told, the radar data indicated that the material is homogeneous, of negligible rocky composition, and attenuates signal the way water does. This left little doubt that the vast majority of the material beneath these lobate debris aprons is in fact water ice (Holt, 2008).

The thickness of the superficial debris covering these subsurface glaciers could not be determined due to vertical resolution limitations on the radar. However, the unobservability on the basis of this limitation at least indicates that the surface covering is on the order of 10 meters or less (Holt, 2008). Such thin self-burying behavior on the part of glaciers is not unheard of in terrestrial analogs. Elliot Glacier on Mount Hood is partially buried by a process of plucking rocks from its accumulating end and bringing them via plastic ice flow to the surface near its bottom. If a glacier continues this plastic sedimentary conveyance for a sufficiently long time, its terminal moraine can eventually convey debris so as to merge with its headwall and be fully buried. Such processes may have also caused the lobate debris aprons surrounding the eastern Hellas massifs to bury these martian glaciers.

From this data, it was estimated that the aprons surrounding the massifs of the east Hellas basin contain approximately 28,000 cubic kilometers of relatively pure water ice, or about 1% of the total average water ice volume of the polar caps (Holt, 2008). It has been suggested that as much as ~90% of the total initial outgassed water of Mars is unaccounted for by surface ice or exospheric escape. The remaining explanation appears to be that most of the water outgassed by Mars during its planetary accretion and differentiation is frozen in a subsurface cryosphere. In addition to those areoglaciological features observed in eastern Hellas, similar observations and inferences from morphology have placed significant cryospheric ground ice beneath many regions of Mars: most prominently the northern provinces of Tharsis and Elysium. Many of these regions beyond Hellas exhibit thermokarstic pits, patterned terrain, seemingly aqueous crater morphologies, and debris flows associated with ground ice. It is possible that some of the water held beneath the surface in ice formations may exist in liquid form (Rossbacher, 1981).

The lobate debris aprons on the massifs of the eastern Hellas basin were revealed to 
be massive covered water glaciers of great purity. If other lobate debris aprons on Mars are interpreted to be similar in composition, it can be inferred that they represent the largest nonpolar water reservoirs on Mars. These and similar cryospheric features are crucial to a proper hydrological understanding of Mars, and may be the primary locations of concern regarding most martian water. These subsurface glaciers represent vital sites of interest to the continuing search for martian life. Should manned exploration or settlement of Mars take place, such thinly-buried, pure glacial deposits will prove invaluable to in-situ resource utilization and sustainable civilization.

Works Cited
Forget, F. et al. "Formation of Glaciers on Mars by Atmospheric Precipitation at High Obliquity." Science 311.5759 (2006): 368-71.
Holt, J. W. et al.. “Radar sounding evidence for buried glaciers in the southern mid-latitudes of Mars.” Science, 322 (2008) 1235-1238.
Mutch, Thomas A. The Geology of Mars. Princeton, NJ: Princeton University Press, 1976.
Pierce, T., and David A. Crown. "Morphologic and Topographic Analyses of Debris Aprons in the Eastern Hellas Region, Mars." Icarus 163.1 (2003): 46-65.
Rossbacher, L. "Ground Ice on Mars: Inventory, Distribution, and Resulting Landforms." Icarus 45.1 (1981): 39-59.
Squyres, Steven W. "The Distribution of Lobate Debris Aprons and Similar Flows on Mars." Journal of Geophysical Research, 84.B14 (1979): 8087.

Wednesday, October 10, 2012

Smoking in Space: Literature, Technology, and Physiology

In constructing a science fiction tale, authors often find it useful to employ gimmicks—constructs employing technical or physical impossibilities—as devices to propel the story into new settings and inject it with certain qualities. Such commonly understood gimmicks include superluminal flight, artificial gravity, and time travel (arguably a subset of faster-than-light travel.) One such gimmick may seem a minor detail, but has much room for technical discussion: the activity of smoking while on-board a spacecraft. It has occurred in many forms of science fiction media from early to recent. The current technical consensus on the matter rules the act as an impossibility. However, examination of the pertinent literature reveals that this may be a technical impossibility rather than a physical one, implying a potential future possibility for the practicality of smoking in space. Literary, technical, and physiological aspects of space smoking shall be considered.
The problems presented by smoking in space have understandably not been overcome or even attempted by present or prior generations of astronauts. Smoking is an inherently recreational act (excepting a sharp minority of medicinal cases) with what are typically considered neutral to negative physiological effects upon the participant, depending on the plant matter in question. It requires continuous combustion, which in turn draws on finite oxygen supplies, releases pollutants into a closed-air environment, and presents a fire risk. Given the current government-operated spacefaring regimes' collective emphases on mission safety and astronaut health, such questions were not likely to arise (at least to be taken with any seriousness.) However, as the 21st century has witnessed the birth of viable privatized spaceflight, the aspirations of private residence and pleasure travel in space seem near at hand. Private individuals, and not solely government employees, will begin entering space for their own purposes. Questions pertinent to the creature comforts of these future private spacefarers will inevitably arise. There has never been a better time to have a serious discussion about the prospect of smoking in space.
Robert Heinlein provided one of the earliest science fiction explorations of smoking in space in his 1939 short story Misfit, wherein a character affixes a “smoke filter” to his face prior to lighting his cigarette. No further description of the device is given, but Heinlein here presented the idea that the problem of smoking in a sealed spacecraft could be solved in some fashion via a specialized device. As it was used by the smoker and not other passengers, it is perhaps implicit that this device confined the smoke to the user's person and the apparatus. Containing the cigarette, the combustion, and the smoke in a face-affixed apparatus may be a viable—however unwieldy—solution, given the invention of such a device. It would need to be capable of sealing in the smoke produced as a byproduct, and then either filter or otherwise dispose of both the secondary smoke and the primary exhalation from the user. Efficient filtration of smoke may be a simpler technical matter in microgravity environments than it is under the influence of terrestrial gravity, for reasons discussed below.
The probability of dangerously rapid combustion of any hydrocarbon ignition upon a spacecraft was once a gravely prohibitive risk for smoking in space. Early spacecraft environment systems, such as those of the Apollo era, used low-pressure atmospheres composed predominantly of oxygen with some water vapor and carbon dioxide. Keeping atmospheric pressure low by leaving out common buffer gases like nitrogen and argon allowed for a lighter, more airtight spacecraft. However, the absence of buffer gases and high oxygen concentration created such a deadly fire hazard that all modern pressurized spacecraft use nitrogen-buffered atmospheres of approximately terrestrial pressure (Friedman, 1999.) Thus, the risk of runaway combustion reactions from cigarette ignition or smoking is negligible for modern spacecraft.
Barring the implementation of an unwieldy containment vessel for the combustion (or presuming its inefficiency in containment,) the pollutants in smoke must be addressed with respect to their effects on the environment. Smoking produces such pollutants as carbon monoxide, hydrogen sulfide, butadiene, benzene, and styrene (Huber, 1989 and Moir, 2008.) No direct observation of dried plant matter burning in a microgravity environment has been made, but analogs can be found in paper and candle smoke observed in smoke detector experiments on board the International Space Station. Smoke of the sort produced by paper, candles, and cigarettes is of a sooty nature. In the ISS experiment, soot particles condensed to more than twice their average terrestrial size due to an absence of the buoyancy effects that typically draw smoke particles quickly from their high-temperature formation zone (Urban, 2005).
The ISS presently uses lithium hydroxide canisters containing activated charcoal in the air revitalization subsystem of its Environmental Control and Life Support System for removing carbon dioxide and biogenic or trace contaminants (Dumoulin, 1988.) Were such filters increased in number relative to the habitat size (or concentrated in an airlock-segregated designated smoking area), they could filter cigarette smoke with a safe level of efficiency. Such filters would likely be used in such settings as the Zion torus space station from William Gibson's 1986 novel Neuromancer, an entire space colony of ganja-smoking Rastafarians. Such cannabis smoke, especially in the concentrations a colony of space Rastafarians would likely produce, would quickly become toxic under normal conditions. In terrestrial filtration schemes micropore density in the activated charcoal filter would need to be increased above that of typical filters in order to address the smallness of cigarette soot particles, but the size change that microgravity endows soot would likely negate this need.
It is worth noting that the carcinogenicity of tobacco smoke is a function of the heterogeneity of smoke particle deposition within the respiratory tract, which in turn is a function of particle size (Balásházy, 2003.) Whether this makes smoking in space safer or more dangerous may be the subject of future study, but that a difference should exist one way or the other makes this a potentially significant subject of scientific inquiry. Future smokers may find their lifestyle choice more or less deleterious to their health depending on the gravity of their setting.
Smoking in space presents a technical challenge for spacefaring pleasure-seekers, but it is far from an impossibility. Given adequate safety and health precautions, technological development, and perhaps a bit of preliminary clinical research, spacecraft can become a relatively safe environment for smoking. Future astronauts may not need to altogether shirk their earthly pleasures in order to set off for the stars.

Works Cited
Balásházy, I. (2003). Local particle deposition patterns may play a key role in the development of lung cancer. Journal of Applied Physiology, 94(5), 1719-1725. Retrieved from http://jap.physiology.org/content/94/5/1719.short
Dumoulin, J. National Aeronautics and Space Administration, (1988). NSTS 1988 news reference manual. Retrieved from Kennedy Space Center website: http://science.ksc.nasa.gov/shuttle/technology/sts-newsref/stsref-toc.html
Friedman, R. National Aeronautics and Space Administration, (1999). Fire safety in the low-gravity spacecraft environment. Glenn Research Center. Retrieved from: www.asi.org/adb/04/03/14/spacecraft-fire-safety.pdf
Gibson, W. (1986). Neuromancer. Ace Publishing.
Heinlein, R. (1939, November). Misfit. Astounding Science Fiction.
Huber, G. L. (1989). Physical, chemical, and biologic properties of tobacco, cigarette smoke, and other tobacco products. Seminars in Respiratory Medicine, 10(4), 297-332.
Moir, D. (2008). A comparison of mainstream and sidestream marijuana and tobacco cigarette smoke produced under two machine smoking conditions. Chemical Research in Toxicology, 21(2), 494-502. Retrieved from http://pubs.acs.org/doi/full/10.1021/tx700275p
Urban, D. (2005). Detection of smoke from microgravity fires. International Conference On Environmental Systems, doi: 10.4271/2005-01-2930



Tuesday, July 24, 2012

ADHD, Neurodiversity, and Social Utility


Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent, most discussed, and most controversial psychological diagnoses of our age.  The condition has been known by many names historically, such as attention deficit disorder or hyperkinesis.  Awareness of the correlated behavioral symptoms belonging to ADHD dates back to the late eighteenth century, when it was known simply as “mental restlessness.”  Until recently, the causes and exact nature of the condition have remained a puzzle to mental health professionals and educators.  Recent developments in evolutionary psychology have suggested a socially-driven evolutionary purpose for ADHD that was hitherto completely unexpected.  Present understandings of the condition characterize it as a psycho-behavioral disorder, and so any concept of a social utility associated with the condition will necessarily challenge the whole paradigm surrounding ADHD.
For one such as I, having received both childhood and adult diagnoses for ADHD, the implications of this sort of research necessarily extend beyond the scholarly, objective, and scientific.  An understanding of the social significance and potential benefit of ADHD is inexorable from my sense of place within society, and so this project could not be conducted without my facing as many personal questions and insights as I did academic ones.  These implications that make this sort of research all the more crucial, allowing those afflicted with the ADHD condition to find social roles that are informed by the evolutionary role it has historically played.
For some time, ADHD was believed to be a purely modern phenomenon: an aberrant symptom of particular individuals’ dissonance with structured, centralized, agricultural society.  Breakthroughs in genetics have shed doubt on this theory.  Evidence of statistically significant relationships between ADHD and the seven-repeat allele of the gene dopamine receptor D4, as well as other genes, suggest not only a genetic origin (or heterogeneous family of genetic origins), but a role of positive evolutionary significance.  What prior concepts have characterized as symptoms of disorder, such as dangerous behavior, unpredictability, and lack of focus, this research casts in a more neutral light as novelty-seeking, behavioral variability, and adaptability.
The evolutionary significance of ADHD can be summarized as the phenomenon in which “unpredictable behaviour by a minority optimizes results for the group,” as stated in the abstract of the primary basis of this research, “the Evolution of Hyperactivity, Impulsivity, and Cognitive Diversity” (Williams et al).  The social function of ADHD is to provide a society with a minority of members driven to exploration and risk.  Social experiments born of the study of evolutionary altruism have confirmed the measurable benefit that minority risk-taking confers upon the whole of the group.  These benefits are most pronounced in activities such as combat, exploration, and discovery and dissemination of new information.  The behavioral nature of these traits and ethno-geographic distribution of associated genes suggest that they evolved early in human history, facilitating and influencing hunter-gatherer societies and migrations for thousands of years before the advent of technological society, dispensing with theories of a modern origin of the disorder.
Further understanding of the distribution of the aforementioned gene DRD4-R7 lends a special credibility to its significance for social groups for which migration is vital.  The trait is much higher in prevalence among such groups.  In the Americas, for example, where populations have migrated the furthest distance of any such group, indigenous DNA contains DRD4-7R at rates more than double the global mean (48.3% for Americas, compared to 20.6% globally).  If one assumes that this gene is even partially responsible for geographic exploration and migration (as the data suggests), then a natural selection among continuously-migrating populations would result in just such a distribution of the gene among American natives.
Equipped with such an understanding, persons with such neurological differences such as I have are afforded the opportunity to consider our own roles in modern society in such a light.  Entrepreneurship, prospecting, and journalism are examples of fields where a tendency to take risks, push beyond established practices and paradigms, and utilize and disseminate new information are key.  Such callings are highly effective at making positive use of common ADHD traits that might otherwise present themselves as nuisances or obstacles in other fields.
Among these maverick social utilities offered to groups by such individuals, one stands above the rest as vital to the survival of the group: the impetus for migration.  The drive and ability to seek new locales with potentially greater resources and opportunities has doubtless accounted for the survival of human groups, as well as the human species as a whole.  It is likely that ADHD-related minority risk-taking has been the social mechanism for such movements throughout the course of history.  
Unfortunately, human expansion is quickly approaching its upward limit in the habitable areas of 21st century Earth, as well as the ability of its natural resources to support the exponentially-expanding human population.  Traditional opportunities for exploration and expansion are no longer afforded in a world without a frontier of its own.  The talents of thus inclined individuals ought then be applied to frontiers of an economic, ideological, or technological nature.  Otherwise, they may find themselves useful on the emerging frontier of outer space as it opens in coming years.
Due to the dual objective-subjective nature of this inquiry, my conclusion is similarly two-fold.  Based on the evidence of evolutionary selection for ADHD traits and the established utility of its behaviors for social groups, I conclude that their typification as indicative of “disorder” is a misnomer, warranting a total revision of the associated psychological paradigm and an effort on the part of society as a whole to understand and embrace the benefits and usefulness of such behavior.  As to the more personal implications of this inquiry, I have concluded that my own ADHD will serve me immensely well in my own chosen field of extraterrestrial settlement and space entrepreneurship.  A tendency to take risks, seek novelty, and function outside established social convention is both beneficial and necessary to the creation of further opportunities for human progress along the frontiers of place and thought.

Works Cited
Chang, F. M. "The World-wide Distribution of Allele Frequencies at the Human Dopamine D4 Receptor Locus." Human Genetics 98.1 (1996): 91-101. National Center for Biotechnology Information. Web.
Palmer, Erica D., and Stanley Finger. "An Early Description of ADHD (Inattentive Subtype): Dr Alexander Crichton and ‘Mental Restlessness’ (1798)." Child Psychology and Psychiatry Review 6.2 (2001): 66-73. Cambridge Journals Online. Web.
Williams, Jonathan, and Eric Taylor. "The Evolution of Hyperactivity, Impulsivity and Cognitive Diversity." Journal of the Royal Society 3.8 (2005): 399-413. The National Center for Biotechnology Information. Web.

Sunday, April 18, 2010

The Potential and Practicality of Human Settlement on Mars

[final paper for Astrobiology with Dr. Melinda Hutson, Portland State University, Fall 2009]

Introduction

For decades, Martian exploration has been an objective of humanity’s space programs. The motives for this undertaking vary from a desire to better know Earth’s stellar neighborhood, to seeking other spheres of life and evidence about life’s origins, to a desire for new frontiers for man to settle. Mars is Earth’s closest planetary neighbor other than Venus, and has the friendlier environment of the two by far (simply contrast a thin, cold atmosphere and a barren rock surface with a scalding-hot atmosphere thick with sulfuric acid and a semi-molten surface). Mars has been found to contain an abundance of all basic elements requisite to life, and is theorized to have even hosted life in the past. These desires and findings have led scientists to recently theorize and begin planning for eventual human settlements on Mars. In addition, some propose that terraformation be undertaken in order to make all of Mars hospitable to humans and other terrestrial lifeforms.

Astrobiology can be greatly furthered by manned Martian settlements. The direct methods made available by human researchers will allow for much more meticulous searches for evidence of life’s prior existence on Mars. Even if searches for Martian life prove completely unfruitful, there is much astrobiological insight yet to be gained. The ability to observe the behavior of terrestrial organisms in an extraterrestrial planetary environment will provide much deeper insight into the nature of life, its potential for diverse adaptation, and its extremes of tolerance. All this will enrich man’s understanding of life, as well as the potential for life on other worlds beyond Earth and Mars.

Another, more pressing motivating factor behind the establishment of human settlements on Mars is the expansion of human habitation. Many believe that by spreading humanity to settlements beyond the Earth—including not only Mars, but asteroid colonies and the colonization of other planets in this and other star systems—the species will increase its probability of survival. Some take the concept further still, as a manifest destiny to expand to the next frontier of human advancement.

Background

Martian exploration is a human mission now about half a century old. The first attempt at a Mars flyby observation was executed by the Soviet Union in October of 1960 with the secret launch of the craft Marsnik 1, which was unsuccessful. The first successful Martian flyby was executed in 1964 by the NASA probe Mariner 4, which provided humanity’s first proximally obtained photographs of the planet’s surface. Since then, many dozens successful missions have been executed for the exploration of Mars, including orbital flybys, landing craft, and surface-roving robots. Three Martian rover missions have been successfully executed since the 1990s. Each of these rovers has provided substantial amounts of information about the Martian environment, specifically with regard to the planet’s geology and geography.

These missions have greatly enhanced humanity’s understanding of Mars, but the potential for Martian knowledge has only barely been tapped. Manned research will provide direct observation and hands-on, versatile conditions far superior to any remote robot can provide. Lunar missions, both past and future, will have provided humanity with the requisite practice in the execution of manned extraterrestrial missions to enable the undertaking of the much more complex challenge of landing humans on Mars.

Manned spaceflight has been a reality since Soviet cosmonaut Yuri Gagarin undertook a successful orbit of the Earth in 1961. The spaceflight breakthrough most relevant to setting a precedent for Martian missions, however, was the 1969 NASA mission, Apollo 11, in which Neil Armstrong and Buzz Aldrin became the first two humans to land on the moon. Exploration of Earth’s moon provides an excellent analog for future Martian flights, providing samples of the conditions such as the effects of reduced gravity over extended periods on the human body, the psychological and physical effects of long-term crew confinement in a small vessel, and the effectiveness of astronaut life-support systems, and the dynamics of extraterrestrial surface rovers.

The Martian settlement agenda has been pushed heavily of late by organizations such as the Mars Society and popular thinkers like Stephen Hawking. The primary motivating factor behind these high-publicity promotions is human expansion, both as human survivability insurance as well as what is proposed as the next great step in the progress of humankind.

Current Information

Martian settlements, being a field of future speculation, have little in the way of tangible findings per se, but instead remains currently defined and embodied by scientifically speculative planning. The requisites and proposed methodologies are predominantly theoretical, with no direct precedent for sustainable extraterrestrial settlement. However, analog experiments, Martian environmental simulators, and the precedent of manned spaceflight have all been used to create viable models for future colonization.

With a history of 48 years, human spaceflight has been developed, studied, and refined quite extensively. Throughout this process, the science of human survivability in extraterrestrial environments has been developed as a facet. Humans are able to survive in outer space, sometimes for weeks at a time, with the help of life support technology developed for precisely such a purpose. In the future, such technologies can be applied to sustaining the life of colonists on an inhospitable Mars.

Manned lunar missions, planned to recommence within the next decade, will require the further development of much space travel technology, as well as surface negotiation robotics, such as the ATHLETE rover. The ATHLETE, scheduled for construction for the next set of lunar landings, doubles as a potential self-contained human habitat, and hence will prove useful for the negotiation of Mars by explorers in the later future. Another benefit from the course of lunar missions is the furtherance of knowledge they will bring regarding the psychological and physiological effects on astronauts of long-term small-space confinement, increased levels of solar radiation, and reduced gravity. As such, lunar missions will prove complimentary to Martian ones.

With current technologies, spaceflights to Mars take approximately six months, with no capacity for return flight. However, a now-discontinued rocketry endeavor, “Project Orion,” was developed by NASA that proposed an atomic-powered rocket, theoretically capable of performing a 125-day round trip to Mars with a 100 ton payload. Such advancement in space travel technology would be instrumental in the opening of a Martian frontier.
Environment simulators, such as the MESCH (Mars Environmental Simulation Chamber) constructed by Jensen, et al, provide numerous research opportunities for future potential Martian conditions. In the MESCH, a carousel of cylinders is exposed to synthesized Martian pressure, temperature, atmosphere, and radiation. Such simulators are typically used for microbial cultures, testing the ability of various organisms to potentially survive in the Martian climate. Experiments utilizing Mars environment simulators like the MESCH have revealed a great deal of knowledge regarding terrestrial organisms and Mars. One study revealed that some photosynthetic microorganisms could survive Martian pressure, radiation, and atmospheric composition, for instance. Such knowledge will be beneficial to future terraformation projects on Mars.

Discussion

Mounting interest and development in the field of extraterrestrial exploration and colonization is turning speculation about Martian living into a potential reality whose practicality is fast approaching. At present, both NASA and ESA (the European Space Agency) have manned Mars flights as future goals, but project their enactment at about 2050: almost as long from the now as from the beginning of spaceflight to the present day. However, with the synergistic application of various technological and scientific advancements, some speculate a much sooner achievement not only of manned trips to Mars, but of the establishment of human colonies, possibly even capable of self-sustainment.

In “Astrobiology and the Human Exploration of Mars,” Paul Davies presented an opinion that the current “over-safety concerns” have resulted in a “culture of stagnation,” and advocates that space programs “get back to the exploration spirit and willingness of taking risks that was so prevalent during the time of Columbus, Darwin, and Amundson….” He suggested that instead of waiting for a time when sufficient technologies were developed for safe two-way travel between Earth and Mars for astronauts, that one-way missions are much more feasible, and that explorers should be willing to travel out to Mars without expectation of return. This would mean either a consistent flow of resupplying missions, or the establishment of some sort of sustainable habitat on arrival, possibly requiring some level of Martian terraformation.

Terraformation has recently passed from the realm of science fiction into a relatively practical reality. The southern ice cap of Mars contains much carbon dioxide, and several methods have been proposed to melt the ice cap, which would result in both the reformation of oceans, as well as a warming greenhouse effect and increased atmospheric pressure. Potential methods to melt the polar ice include subsurface nuclear blasting, pummeling via piloted asteroids, or the construction of an aluminum orbital solar mirror. Added to this, the fact that some microorganisms have demonstrated the ability to survive in simulated Martian climates means that there is a heavy potential for constructing a sustainable ecosystem on Mars.

Further, if the atomic rocket technologies developed under Project Orion were to be implemented, the necessity of one-way Martian missions could eventually be superseded. Earth-Mars travel time could then decrease to as few as four weeks both ways. Resources and personnel could be transported to and from the Martian surface at rates much quicker than those projected using current rocket technology, and Martian samples could be returned to Earth for study, furthering astrobiological and astrogeological goals.

Though it is still considered a far-off goal by many of those involved, recent and current technological and scientific endeavors have created a potential for Martian colonization in the relatively near future. The proper synergy of developments in astrobiology, rocketry, robotics, and human environment construction may open the door to a new chapter of human advancement. Humanity may quite soon find itself to no longer be a solely Earth-bound civilization.

Resources:

Crawford, I. A. "The astrobiological case for renewed robotic and human exploration of the Moon." International Journal of Astrobiology 5 (2006): 191-97.
Farmer, Jack, and David Des Marais. "Session 29. The New Mars: Habitability of a Neighbor World." Astrobiology 8 (2008): 431-36.
Jensen, Lars L. "A Facility for Long-Term Mars Simulation Experiments: The Mars Environmental Simulation Chamber (MESCH)." Astrobiology 8 (2008): 537-58.
Levine, Joel, and James Garvin. "Session 5. Astrobiology and the Human Exploration of Mars." Astrobiology 8 (2008): 310-12.
Sakon, John J., and Robert L. Burnap. "An analysis of potential photosynthetic life on Mars." International Journal of Astrobiology 5 (2006): 171-80.
"Stephen Hawking calls for Moon and Mars colonies." New Scientist. 05 June 2009 <http://www.newscientist.com/article/dn13748?feedId=online-news_rss20>.
Wilcox, Brian H., Todd Litwin, Jeff Biesiadecki, Jaret Matthews, Matt Heverly, and Jack Morrison. "ATHLETE: A Cargo Handling and Manipulation Robot for the Moon." Journal of Field Robotics 24 (2007): 421-37.
Zubrin, Robert M., and Christopher P. McKay. "Technological Requirements for Terraforming Mars." Madasafish. 05 June 2009 <http://www.users.globalnet.co.uk/~mfogg/zubrin.htm>.