 SUMMARY OF FIELD INVESTIGATIONS FROM THE MARS 160 ANALOG MISSION IN UTAH AND DEVON ISLAND  J.P. Knightly1, J.D.A. Clarke2, S. Rupert3, and A. Srivastava3. 1Arkansas Center for Space and Planetary Science, University of Arkansas, Fayetteville, AR 72701, (jknightl@uark.edu),  2Mars Society Australia, 43 Michell St, Monash, ACT 2904, Australia, 3Mars Society, 11111 West 8 Avenue Unit A, Lakewood, CO 80215 Introduction: The Mars 160 Twin Analog Mission (M160) was a two-phase simulated Mars mission that took  place  over  140 days  between 2016-2017 at  the Mars Society's two analog facilities - the Mars Desert Research Station (MDRS) near  Hanksville,  Utah and the Flashline Mars Arctic Research Station (FMARS) on  Devon  Island,  Canada.  M160  had  two  primary, overarching objectives: to assess the field science return between two similar research facilities in two different Mars analog environments and to assess the psychological impact of each facility's design and location on the crew. Here we provide a brief summary of the field  science activities  that  were carried out  between the two phases of the mission. Figure 1: Photograph of MDRS taken during the first phase of the M160 mission in 2016 (Photo: Yusuke Murakami.) About the Facilities:  MDRS is located along the San  Rafael  Swell  about  7  miles  northwest  of  Hanksville, UT by road. Sitting on red sandstone with maroon hills of bentonite as a backdrop, the facility is surrounded by geology that is both physically and visually analogous to the surface of Mars (Figure 1.) The facility is in a temperate climate and experiences four equal seasons throughout the year. It is easily accessed by a dirt road and flights into the airport in nearby Grand Junction, CO. Since the facility's construction in 2001, it  has  hosted  over  1,000  researchers  and  students  in over  180  simulated  Mars  missions  ranging  from  2 weeks to 3 months in duration. By comparison,  FMARS is located  on Devon Island almost halfway between the Arctic Circle and the North Pole and experiences a short, cold summer during  which  the  majority  of  missions  have  been  conducted. It  is  situated  in a periglacial  environment  on the  rim of  the  39  million-year-old  Haughton  Impact structure. It's geology and climate are ideal for running both  operational  and  field  science  simulations  under environmental  conditions  that  more  closely  replicate the conditions an actual mission to Mars would experience. Despite its remote location and accessible only by air, FMARS has hosted 14 crews since its construction in 2001 in missions ranging from 1 to 4 months in duration and is the proposed location for the year-long Mars Arctic 365 mission. Summary of Field Investigations: Astrobiology: Biological field studies at MDRS and FMARS  focused  on  identifying  biosignatures  in  the form of hypoliths and endoliths. These rock-dwelling organisms  are common on Earth [1]  and serve  as an analog for how present or fossilized life on Mars could adapt to the harsh environment of the planet's surface [2]. Shielded from radiation by living on the underside of  rocks,  hypolith  and  endolith  colonies  could  take hold in regions on Mars where the triple point of water has a chance of being reached in the modern era. In addition,  gypsum  deposits  at  MDRS  [3]  and  inside Haughton  Crater  near  FMARS [4] were  sampled for the detection of putative preserved organic compounds. The finding of gypsum veins on the Martian surface has corroborated the hydrological history of Mars [5], [6]. On the other hand, terrestrial evaporites have been found  to  preserve  the  biological  record,  mainly halophilic life, over a geologic time [1]. Therefore, it is plausible to hypothesize that evaporites might serve as microhabitats if life ever existed on Mars [3], [4]. At  FMARS,  the  areal  extent  and  diversity  of lichens and vesicular plants were documented as a part of ongoing efforts to understand the high arctic biome. The occurrence of several  species was  were noted to have their furthest inland extent on Devon Island, contributing important knowledge to this active biome. Field methods employed in the astrobiology study at MDRS and FMARS included documenting hypolith and endolith colonies using a series of quadrat surveys (Figure 2) and the sampling of ancient evaporites, with both activities conducted in coordination with specialists  "on Earth." Similar procedures would need to be developed and refined for future crewed missions. This study formed the basis for one of the primary comparative  operational  studies  of  M160.  Once  the  sample analysis  effort  from both  phases  of  the  mission  has concluded, a final  determination  can be made of the science return from this project at each site. Geology: Geological field work at MDRS took advantage of sedimentary outcrops to study prehistoric Figure 2:  M160 crew members conducting a quadrat survey while  wearing spacesuits  on Devon Island in  order to document  the  diversity  of  hypolith  and  endolith  colonies (Photo: Paul Knightly). fluvial landforms in the form of inverted and exhumed channels similar to features that have been observed on Mars [7]. At both MDRS and FMARS, fossilized stromatolites were  studied  for their  value as analogs  for how mesoscopic fossils could appear on Mars [8]. The  periglacial  environment  surrounding  FMARS and inside Haughton Crater provides a unique opportunity to study cold-weather processes that have been observed  on  Mars.  Water-ice  permafrost  in  periglacial patterned ground on Devon Island is visually and morphologically similar  to patterned ground observed on Mars that was confirmed by the Phoenix mission to be composed  of  water-ice  [9].  Patterned  ground  in  the vicinity of FMARS was studied to draw comparisons with results from the Temperature and Electrical Conductivity Probe (TECP) on Phoenix [10] through dataloggers deployed in the permafrost active layer. Additionally,  patterned  ground  was  studied  to  determine how it could be impacting the evolution of Haughton Crater and craters in the periglacial regions of Mars via trenching and anaglyph imaging [11]. Additional field work was undertaken to familiarize the crew with the unique geology of the Haughton Impact Crater with an emphasis on collecting samples of impact  breccia,  shattercones,  and  visiting  a  supersite identified by Osinski et al [12] that represents a collection of  the major  observable facies  inside the  crater. The longer traverses into Haughton Crater also faced constraints  due  to  time,  weather,  and  availability  of crew resources - important factors that will impact the manner in which field science activities are conducted on the first crewed missions to Mars. Discussion:  After nearly four years of preparation, Mars  160  concluded  field  activities  in  August  2017 when the crew departed from Devon Island. An early analysis of field samples and data collected in the field have highlighted both the differences of each facility as well as the strengths that each one contributes to the ongoing study of Mars analogs on Earth. The estimated two-year round-trip mission to the surface of Mars and back will be the longest mission in human spaceflight history.  However,  many  of  the  recent  long-duration Mars  mission  simulations  have  focused  primarily  on the psychological  impact  of crews in extended isolation without an intensive field science program for the crew. While understanding the impact of isolation by itself is important  to understanding crew dynamics,  a mission to Mars will be one of active exploration with perhaps as much as half of the mission being spent on the surface. Mars 160 was focused on implementing a strong field science program in order to better understand the role of field science in analog missions, with implications  ranging  from crew dynamics  and  selection up to the final design of the field science program on the first crewed mission to Mars. Future Work: The science return from MDRS and FMARS will continue to be analyzed over the near future. With nearly four years of work leading up to the conclusion of the field portion of the study, post-mission sample and data analysis has by comparison only just  started.  Additional  reports are expected to be issued over the coming years as findings from the field and  psychological  studies  become  available.  Future long-duration missions  will  be developed for  MDRS and FMARS using guidance from the results of Mars 160 to make the most efficient use of each facility. Acknowledgements: This research would not have been  possible  without  the  contribution  of  our  M160 crewmates - Annalea Beattie, Claude-Michel Laroche, Alex  Mangeot,  Yusuke  Murakami,  and  Anastasiya Stepanova. We are grateful to Robert Zubrin for organizational  and  financial  support  and  vision,  Paul Sokoloff in his role as co-PI and Arctic expert, Vincent Chevrier, Hanna Sizemore, and Matt Siegler for their expertise  in  Mars  periglacial  and  environmental  processes,  and  to  Chris  McKay,  Kathy  Bywaters,  and Charles Cockell for their input into biological matters. References: [1]  Lowenstein  T.K.  and  Schubert B.A. (2011)  GSA Today, 21, 4-9. [2] Warren-Rhodes K.A.  and  McKay C.P. et  al (2013)  JGR, 118, 14511460.  [3]  Young B.W. and Chan M.A.  (2017)  JGR, 122, 150-171. [4] Parnell J. and Lee P. et al (2004) International Journal of Astrobiology, 3, 3, 247-256. [5] Squyres S.W. and Arvidson R.E. Et al (2012) Science, 336, 6081, 570-576. [6] Nachon M. and Clegg S.M. et al (2014)  JGR, 119,  9,  1991-2016. [7]  Clarke  J.D.A and Stoker C.R. (2011) International Journal of Astrobiology,  10,  161-175.  [8]  McKay,  C.P.  and  Stoker C.R., (1989)  Reviews of Geophysics, 27, 189-214. [9] Mellon M.T. and Aridson R.E. et al (2009) JGR, 114. [10] Zent A.P. and Hecht M.H. et al (2010) JGR, 115. [11] Knightly J.P. and Murakami Y. et al (2017) AGU 2017 Fall  Meeting,  266391.  [12]  Osinski  G.  R.  and Lee P. et al (2010) Planetary and Space Sci., 58. 
