Devon Island is also astonishing by virtue of the resilience of the life that can be found there. Life in polar deserts usually persists at the edge of what is possible. Liquid water is rare - as are essential nutrients. Our studies of microbial life at Haughton Crater, led by HMP chief biologist Charles Cockell of the British Antarctic Survey, are revealing stories of survival and adaptation with potential implications for our search for life on Mars and elsewhere.
For example, in spite of the high ultraviolet (UV) radiation environment prevailing during the summer with its 24 hours of unrelenting sunlight, microorganisms are able to avoid radiation damage by remaining shielded. Many do so by simply colonizing sheltered areas underneath rocks or in soils. Other organisms, such as algal mats living at the bottom of open shallow ponds and puddles, have evolved natural sunscreens.
Just as humans don a spacesuit so as to survive in an otherwise lethal environment, these microbial colonies coat themselves with a gelatinous pigment-rich UV-screening compound that is secreted to form a protective biofilm. Long after the microorganisms themselves have died, the biofilms they produced can remain intact. This could serve as the basis for one of the ways we might search for past life on Mars. Through high-resolution remote sensing, instruments could search for the telltale signatures of resistant biological compounds which putative microorganisms might have evolved to survive in the planetÕs harsh UV-drenched near-surface environment.
Impact Events: They're Not Always Bad News
The HMP team has also found that the inside of Haughton Crater's battered rocks can serve as a host location for colonization by cyanobacteria. The existence of so-called "endolithic" microbial communities (microbes living inside rocks) is not new. Such colonies were first identified more than 20 years ago by Imre Friedmann in sandstone rocks found in Antarctica's Dry Valleys. Until now, these endolithic colonies had only been found in more porous and translucent sedimentary rocks - not in crystalline rocks, which are typically very compact and opaque. At Haughton Crater, however, crystalline rocks have been so heavily fractured and rendered porous by the impact that they are now home to thriving colonies of cyanobacteria.
The usual tone of any description of large impact events and their effect upon life is 'bad news'. This may not always be the case. Large catastrophic impact events certainly threatened highly evolved and narrowly adapted species such as dinosaurs and mammals - organisms that relied upon complex and vulnerable food chains below them. Curiously, however, large impacts could also have offered microbial life shelter and warmth when they needed it the most, that is, on early Earth and possibly early Mars. They can also create habitable zones - albeit transient ones - in otherwise hostile (cold) locations.
In addition (as mentioned in "Hitchhiking on a Meteorite: Is there Mars Life on Earth?" in this issue), large impacts are capable of launching rocks from one planet to another. Thus, not only do impacts serve as Nature's interplanetary launch mechanism, they might also create suitable rock vessels for the successful transfer of microbial life from one world to another. Ironically perhaps, impacts and the emergence and survival of microbial life might be intimately connected, indeed perhaps inextricably tied.
During our first season on Devon Island in August, 1997, it became clear that the Haughton Crater site offered a unique opportunity to learn more about not only Mars and the Earth, but also about how actual humans will explore Mars and other planetary destinations in the future.
In addition to presenting us with a polar desert setting, Devon Island is also rugged, vast (20 times the area of the Antarctic Dry Valleys), diverse in terrain types, unpopulated, radio-quiet, tree and power line-free (important for aircraft operations), remote, isolated, and still poorly mapped. All of our activities on the island have to be carried out with attention to potential life or death consequences. Small mistakes can become big problems quickly. The isolation and remoteness of the site render medical help difficult to access. This will also be the case, to a greater degree even, for humans on Mars.
Adding to the intrinsic value of the site is the fact that we are engaged on Devon Island in actual field work, not simulations thereof. We are engaged in the very process of field exploration in a setting that's operationally relevant to Mars, in a place that we genuinely want to understand. Here, we can test out new robotic systems, learn valuable lessons about how humans will one day explore Mars, and eventually train the astronauts who will make the journey.
While quite a bit of thinking has already gone into the question of how to get humans to Mars and back, much less thought and virtually no dedicated field studies have addressed what Mars travelers will do once they get there.
These are but a few questions that might seem straightforward to answer but actually are not given the large number of conceivable mission scenarios and the fast pace of technology progress.
Lessons can be drawn from the Apollo missions, but only in a limited way. Humans on the Moon had very little total surface time. EVAs were few and were scripted in detail. Little deviation was possible. Also, being located only 1.5 light-seconds away, Mission Control had almost instantaneous situational awareness and followed and supported the explorers essentially "live".
On Mars, the situation will be very different. Extended sojourns are envisaged while the time barrier associated with the much greater Earth-Mars distance (4 to 20 light-minutes each way) will preclude any true live interaction with Earth. Mars explorers will be to a large extent on their own. Mission Control becomes something fuzzier, "Mission Support", with lesser ability to control things directly because of the delayed situational awareness, but with a role still likely to be critically important to enable mission success.
On Devon Island we are faced with an opportunity to investigate how field exploration is done, how it can be optimized for field safety and science yield, what effects specific constraints associated with Mars exploration might have (limited EVA time, need to remain within walk back distance to survival shelter and supplies at all times, etc.), and how new technologies and strategies can help enhance exploration.
Over the years, a number of exploration research activities have taken place under the auspices of the HMP. A regular partner in these efforts has been the Robotics Institute of Carnegie Mellon University (CMU). In 1998 and 1999 the HMP worked with Omead Amidi and his team on the performance of autonomous and teleoperated helicopters in support of field research activities. In 1999 we also worked with Dimi Apostolopoulos and his group on field studies to define the requirements of future robotic roving assistants for human explorers. Most recently, in 2001, CMU researchers led by David Wettergreen and Red Whittaker conducted the highly successful field trials of the sun-synchronous (sun-tracking) "Hyperion" rover at Haughton Crater.
These efforts in robotics development have an immediate application for the design of more capable autonomous systems that will soon find their way on new robotic spacecraft bound for Mars or other destinations in space. But as robots improve in sophistication, their ability to interface with humans in complex ways is also making strides. A tight partnership between humans and robots may in the end emerge as the most powerful exploration system we can develop, one that would see not robots exploring Mars in place of humans or vice versa, but one in which humans and robots explore in tandem.
At the heart of all robotic systems designed for planetary exploration, and indeed at the core of all human exploration activities, will be a need for substantial capabilities in communications, computing, and networking.
In 1999, a communications network set up on the HMP by Rick Alena from NASA Ames Research Center and Stephen Braham, Director of the PolyLAB SpaceSystems Group at Simon Fraser University allowed initial field tests of wireless high-bandwidth communication systems in support of robotic and human exploration. Once established, the network was used to support embryonic interactions with the Exploration Planning and Operations Center (ExPOC), a newly-created mission control center at NASA Johnson Space Center designed to serve as a simulation testbed for future advanced human space exploration missions.
For a period of two weeks that summer, field activities reports and science findings were downlinked daily while future science requests, troubleshooting tips, weather forecasts, and news were uplinked in exchange. In all these exchanges, one-way time delays of up to 20 minutes were introduced to simulate the time barrier that would exist between the Earth and Mars during an actual Mars missions. The experiment was a success and led to a higher fidelity simulation in 2000. Among the key lessons learned was that unless comprehensive automated procedures are in place, the need to convey adequate situational awareness to Mission Support back on Earth will place a heavy time burden on any crew on Mars. While this was suspected going in, the HMP simulation allowed actual and quantitative operational experience to be gained.
In subsequent years, Steve Braham, now the HMP's Chief Field Engineer, has continued to expand the sophistication of the communications, networking and in-situ computing infrastructure on Devon Island so as to test out a wide array of protocols and hardware. All of this is done with a key focus on supporting future complex robotic and human exploration activities on Mars and the coordination of all of these events with Earth.
Related to this research are studies performed by Bill Clancey, director of the Human-Centered Computing research group at NASA ARC. Clancey's research has focused on the specific interactions and information exchanges between humans engaged in exploration (with one another in the field and with their peers back at Mission Support), their tools (computers, robotic assistants, rovers, rock hammers), and their living space (habitats, tents, furniture). The information collected, akin to data gathered by ethnographers, is analyzed by Bill and his team and then fed into computer simulation models designed to eventually help plan and optimize future human exploration missions.
Perhaps one of the most far-reaching findings emerging from our HMP exploration studies is the confirmation of the key role that ATVs (all-terrain vehicles or "quads") could play as personal mobility systems in support of the surface exploration of Mars (or the Moon). The use of individual motorized vehicles is not new per se. Personal astronaut motorcycles were designed and tested during the Apollo program, but never made it to the Moon. Still, the idea of having spacesuited explorers drive individual ATVs had never gone far beyond the concept stage.
Our use of ATVs on Devon Island, sponsored by Kawasaki Motors USA, combined with the prior experience of some of our team members with snowmobiles in Arctic and Antarctic field research, is allowing operational benefits of such mobility systems to be evaluated. ATVs offer a high degree of flexibility and reliability, through redundancy in particular, in field exploration activities.
Any ATV-like vehicle taken to Mars will need to be optimized for safety, power consumption, performance on different terrain types (dunes, rock fields, salt flats), and ride comfort. They will also need to be robust, equipped with redundant systems, and most of all, easy to repair. Range of use also needs to be understood. Our studies suggest that ATVs are best used for activities within a few miles or so from a local base (a shirt-sleeve haven such as the base habitat or a pressurized rover). Beyond that distance, exploration is safely and effectively conducted likely only by pressurized rover. The best mix of short and long range capabilities will probably be provided by a trailer (with several ATVs aboard) towed behind a pressurized rover. When necessary, astronauts would go EVA from the pressurized rover and conduct local explorations using the ATVs.
The spacesuit that will be used on the Martian surface will be one of the most complex pieces of hardware that will need to be developed in order to enable effective human Mars exploration. A spacesuit should be viewed as a wearable spacecraft. Compared to spacesuits in use today, the Mars surface suit will need to operate for much longer periods of time, be easily and repeatedly cleaned and repaired, comfortable to wear for many hours at a time on difficult terrain, and be capable of supporting its wearer in a wide variety of conditions. The suit will also have to support information systems that will allow astronauts on Mars to communicate and handle data effectively.
It is important to note that current EVA suits in use on the International Space Station and Space Shuttle can only be used for a matter of tens of hours before requiring a complete overhaul. Apollo Lunar suits were rendered almost useless by lunar dust after only a few excursions onto the lunar surface. Moreover, they were bulky and tiresome to use. While a few days of hardship inside a stiff suit can be adapted to, exploration activities over the course of several months on Mars would suffer greatly if a poorly designed suit were to be used repeatedly.
Current estimates of the target felt weight on Mars of a future Mars suit are in the 50-70 pound (~25-35 kg) range, i.e., the spacesuitÕs actual mass might be 130-185 pounds [~65-95 kg]. While this weight may seem high, these numbers should be compared to the mass of the current Space Shuttle/ISS EMU spacesuit system: over 300 pounds [150 kg]. Because of its use in zero g, Shuttle and ISS astronauts are still able to wear their suit relatively comfortably, but such a suit would be inadequate on Mars. Its felt weight would be 115 lbs, an impractical burden to bear, not to mention the fact that the EMU suit was not designed for walking to begin with.
As such, doing work on the design requirements for Mars surface suits now, even at moderate pace, may provide an important headstart. NASA JSC is currently leading an advanced spacesuit development effort that will help pave the way for a future Mars suit. Realizing the importance of advancing suit system development now as well, the aerospace company Hamilton-Sundstrand has also been devoting some internal R&D resources to develop a concept spacesuit for advanced planetary exploration.
One highlight of the field tests performed to date is the establishment of multiple-relayed wireless links and the remote control of field computers on geology-driven simulated EVAs. Control was established over distances in excess of 2 km. Use of integrated information systems in support of EVAs will be critical for ensuring the safety and productivity of future human exploration activities on Mars - and indeed at any other location in the solar system.
A recently added element to the HMP is the Flashline Mars Arctic Research Station (FMARS). The project has its genesis back in 1998 when I suggested to Robert Zubrin (who was then in process of forming the Mars Society) that this new organization should look at contributing a simulated Mars habitat to our ongoing efforts on Devon Island as its first project. The premise was that such a habitat would provide a more constrained framework for carrying out some of our studies of how humans will live and work on Mars, and at the same time serve as a visible and tangible symbol of the societyÕs stated goal - help send humans to Mars.
Through the efforts of many, the Flashline Mars Arctic Research Station (named after an early major sponsor) was eventually established near the HMP Base Camp on the rim of Haughton Crater in July, 2000. During the 2001 field season, a rotation of six crews, each comprising between 5 and 7 people, lived and worked out of the "Hab" for 5 to 10 days at a time, allowing a first wave of valuable operational experiences to be logged.
For the simulated EVAs performed out of the Hab, Mars Society volunteers had produced simulated spacesuits. While these suits were of low fidelity in many respects (they weighed only 25 pounds [12 kg], were not pressurized, and did not restrict motion significantly), they were nevertheless good to have for three reasons. First, the suits took 25-35 minutes to put on, requiring that a checklist be followed and the buddy system be used. Thus, their use imposed an operational burden that was not unrealistic for an actual suit that might be used on Mars. Second, the suits restricted the wearer's vision in a relatively realistic manner. Thirdly, the suits, by virtue of their good looks, served as an effective and important tool for public outreach.
While public outreach continues to be an important aspect of the FMARS activity, HMP science and exploration programs were also brought into the mix in support of FMARS research. During the shifts I participated in (I served as crew commander on 4 of last summer's 6 crews), we performed field work with specific operational constraints and procedures defined in consultation in particular with the Exploration Office at NASA JSC.
The underlying assumptions for these simulated EVAs included simulated pure oxygen prebreathing time prior to egress so as to simulate specific cabin pressure and air composition conditions. We also limited the duration of our EVAs so as to adhere to plausible life support system operation times. These time limits were usually 2-3 hours on a backpack which would be used while walking, and 2-3 additional hours assumed to be carried on the ATV and used while riding the vehicle. For simulation of safety margins, 30 minutes of "don't use it" time were added to both suits and ATVs for all EVAs. We also made use of (imaginary) pre-positioned caches of supplies (including auxiliary oxygen) in the execution of extended traverses.
Field traverse planning, science implementation, and in-hab data analysis were carried out in consultation with an experimental "Science Operations Center" established at NASA Ames Research Center by Michael Sims, Kelly Snook, and Carol Stoker. Jeffrey Moersch of the University of Tennessee, Melissa Lane of the University of Arizona, and James Rice of Arizona State University served as the Earth-based science team.
One lesson emerging from the field traverse simulations performed to date is a quantitative assessment of the duration of EVA cycles in support of exploration activities. Extended exploration EVAs on Mars will require that substantial amounts of crew time and Mission Support resources be spent on the careful planning (including possibly reconnaissance robot deployments and the pre-establishment of caches), implementation (the actual EVA), post-EVA data analysis, and communications with Earth. While pre-mission crew training, robotic reconnaissance and caching, and the development of effective EVA planning tools will clearly help streamline EVAs, extended exploration traverses on Mars will, in a true sense, remain expeditions within an expedition, mobilizing each time a substantial fraction of the crew.
EVAs will indeed require significant coordination between both the EVA and IVA crews (IVA or Intravehicular Activity crewmembers are those individuals remaining inside the Hab) in order to implement safe and productive EVAs. Given our preliminary experience on Devon Island, one might expect that extended exploring EVAs out to several kilometers from base camp on the surface of Mars will occur with a frequency of no more than once per week or so. As such, perhaps only 50-60 extended EVAs might be expected to occur over the course of an 18 month stay on Mars. Given this assumption, EVA time will remain a precious commodity, one that needs to be afforded significant preparation time.
Upcoming seasons will see the addition of new research elements to the NASA HMP. One of these will be the "Arthur Clarke Mars Greenhouse", a 12 x 24 feet long experimental facility recently donated to the SETI Institute for the HMP by SpaceRef Interactive Inc. Slated for initial deployment in 2002, this greenhouse will allow HMP researchers to carry out a variety of astrobiology and space biology experiments in the field, and also test out advanced life support system technologies for future Mars exploration. On another front, a specially modified Humvee, sponsored to the SETI Institute for the HMP by AM General, may also begin service on Devon Island in 2002 as a long-range field exploration roving lab. Through its use in support of actual field research, the rover will be used to help define over time the requirements for long-range pressurized rovers to be deployed by humans on future Mars missions.
As a planetary scientist, I am a strong supporter of the human exploration of Mars, which I view as the most effective means of learning more about this and other planets and the possibilities of life. But there are many other reasons why humans should go - many of which may be unrelated to science. In the end, rather than science alone, it is likely to be the broader factor of national interest that will drive a nation - or a group of nations - to undertake a human mission to Mars. Going to Mars now would serve our national interest in an ideal way as it would be a powerful investment in our future on Earth, regardless of what we are to find on Mars.
But why Mars? Why not the Moon, asteroids, or Pluto, or a technology program with universal applicability but no specific focus? It is here that the specific scientific potential and complexity, and the undeniable public appeal of Mars kick in: a) Mars might have once harbored life and might still ; it is a world promising new knowledge and potential revolutions in the life sciences and many other disciplines ; b) Mars is a planet bearing clear similarities to the Earth and is more directly able to help us understand and manage our own planet ; c) Mars is a planet actually accessible to human exploration and its exploration would be much better done by humans on site rather than remotely from Earth ; d) Mars represents a goal that would provide a clear and well-defined focus for the nationÕs space program, the latter being a capability that needs to be sustained anyway as a matter of national interest in its own right.
If our micro-scale experience on the NASA HMP analog project has been any indication, going to Mars, if initiated through a government effort, would likely draw in significant participation from the private sector. It would also provide an ideal opportunity for international cooperation, building on the ISS experience and binding allied and friendly nations in a positive, forward-looking enterprise that would help promote world peace, education, human knowledge, and a more secure global future. And did I mention that going to Mars will also be exciting?
Dr Pascal Lee is a planetary scientist at the SETI Institute and is based at NASA Ames Research Center in Moffett Field, California. He is Project Lead and Principal Investigator for the NASA Haughton-Mars Project on Devon Island, Nunavut, Canada.
For more information on the NASA HMP, visit www.marsonearth.org.