P089-03
The Comet Astrobiology Exploration SAmple Return (CAESAR) Mission
Thursday, 17 December 2020: 05:36
Virtual
Alexander G Hayes Jr1, Keiko Nakamura-Messenger2, Steven W Squyres3, Daniel Patrick Glavin4, David F Michell5, Martin B Houghton5, Donya Douglas-Bradshaw5, Dante S Lauretta6, Kazuhiko Yamada7, Yoshihiro Furukawa8, Yuki Kimura9, Don Wegel5, James E Parker5, Michael J Mumma10, Stefanie N Milam10, Perry Gerakines10, Jonathan I Lunine11, Julie Mitchell12, Lisa Pace2, Christopher D K Herd13, Stephen Gorevan14, Hume Peabody5, Jason P Dworkin4, Ann Nguyen2, Simon J Clemett15, Thomas J Zega16, Erwan M Mazarico10, David D Rowlands10, Shahid Aslam10, Nicolas Gorius17, Justin Spring18, Kris Zacny18, Phillip Chu19, Carsten Güttler20, Holger Sierks20, Jean-Baptiste Vincent21, Nilda Oklay22, Humberto Campins23, Yanga R Fernandez23, Joseph Makowski24, Elizabeth Morse24, Jason M Soderblom25, Dennis Bodewits26, Samuel Birch27, Michael S.P. Kelley28, Bjorn Davidsson29, Anton V Kulchitsky30, Randolph L Kirk31, Michael T Bland32, Laurie A Leshin33, Karin Oberg34, Michael A Ravine35 and CAESAR Project Team, (1)Cornell University, Astronomy, Ithaca, NY, United States, (2)NASA Johnson Space Center, Houston, United States, (3)Cornell Univ, Ithaca, NY, United States, (4)NASA Goddard Space Flight Center, Solar System Exploration Division, Greenbelt, MD, United States, (5)NASA Goddard Space Flight Center, Greenbelt, United States, (6)University of Arizona, Lunar and Planetary Laboratory, Tucson, AZ, United States, (7)JAXA Japan Aerospace Exploration Agency, Sagamihara, Japan, (8)Highlands Ranch, CO, United States, (9)Hokkaido Education University, Sapporo, Japan, (10)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (11)Cornell University, Department of Astronomy, Ithaca, NY, United States, (12)Arizona State University, Tempe, AZ, United States, (13)Univ Alberta, Edmonton, AB, Canada, (14)Honeybee Robotics New York, Brooklyn, NY, United States, (15)ESGC at NASA JSC, Houston, TX, United States, (16)University of Arizona, Tucson, AZ, United States, (17)Catholic University of America, Washington, DC, United States, (18)Honeybee Robotics, Pasadena, United States, (19)Honeybee Robotics New York, Brooklyn, United States, (20)Max-Planck Institute for Solar System Research, Goettingen, Germany, (21)DLR Institute of Planetary Research, Berlin, Germany, (22)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (23)University of Central Florida, Orlando, FL, United States, (24)Northrop Grumman Space Systems, Dulles, United States, (25)MIT, Cambridge, MA, United States, (26)Auburn University, Auburn, AL, United States, (27)University of California Berkeley, Berkeley, CA, United States, (28)University of Maryland College Park, Astronomy, College Park, MD, United States, (29)NASA Jet Propulsion Laboratory, Pasadena, United States, (30)University of Alaska Fairbanks, Fairbanks, NH, United States, (31)USGS Astrogeology Science Center, Flagstaff, AZ, United States, (32)Washington University, St. Louis, MO, United States, (33)Rensselaer Polytechnic Institute, Troy, NY, United States, (34)Harvard-Smithsonian Center for Astrophysics, Cambridge, United States, (35)Malin Space Science Systems, San Diego, CA, United States
Abstract:
The Comet Astrobiology Exploration Sample Return (CAESAR) mission will acquire and return to Earth for laboratory analysis a minimum of 80 grams of surface material from the nucleus of comet 67P/Churyumov-Gerasimenko (67P). CAESAR will characterize the surface region sampled, preserve the collected sample in a pristine state, and return evolved volatiles by capturing them in a separate gas reservoir. NASA Goddard Space Flight Center provides project management, systems engineering, safety and mission assurance, contamination control, mission operations, and many other important functions. Northrop Grumman Space Systems will build the spacecraft, based on Dawn mission heritage, which like CAESAR, uses solar electric propulsion. CAESAR was selected by for Phase A study in the New Frontiers 4 Competition and will be proposed to New Frontiers 5.
Collection of a sample from the surface of comet 67P is facilitated by a set of cameras that together provide images to support sample site selection, perform optical navigation, and document the sample before, during, and after collection. The sample is collected at the end of an arm during a 5-second touch-and-go (TAG) maneuver with the Sample Acquisition System (SAS) designed by Honeybee Robotics for the surface properties of comet 67P observed by the Rosetta mission. After sample collection, and while the sample is still cold (< -80°C), the TAG Arm inserts the sample container into the Sample Containment System (SCS) mounted inside the Sample Return Capsule (SRC). The SCS is sealed, preventing the sample from escaping into space. The sample is slowly warmed inside the SCS to enable sublimation of volatiles, which are collected in the Gas Containment System (GCS), a passively cooled gas reservoir. Separating the volatiles from the solid sample protects the solid sample from alteration. Once all sublimated H2O is transferred to the GCS, the GCS is sealed to capture the volatiles it contains, and the SCS is vented to space to maintain the solid sample under vacuum. The SCS vent is closed before Earth entry to prevent atmospheric contamination.
Detailed laboratory analyses of the sample from 67P will trace the history of volatile reservoirs, delineate the chemical pathways that led from simple interstellar species to complex molecules, constrain the evolution of the comet, and evaluate the role of comets in delivering water and prebiotic organics to the early Earth. CAESAR will achieve these goals by carrying out coordinated sample analyses that will link macroscopic properties of the comet with microscale mineralogy, chemistry, and isotopic studies of volatiles and solids. Most of the sample (≥75%) will be set aside for analyses by generations of scientists using continually advancing tools and methods, yielding an enduring scientific treasure that only sample return can provide. This presentation will review development conducted during NF4 Phase A and discuss the NF5 mission concept.
