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44th Lunar and Conference (2013) 1915.pdf

INSIGHT: A DISCOVERY MISSION TO EXPLORE THE INTERIOR OF . W. B. Banerdt1, S. Smrekar1, K. Hurst1, P. Lognonné2, T. Spohn3, S Asmar1, D. Banfield4, L. Boschi5, U. Christensen6, V. Dehant7, W. Folkner1, D. Giardini8, W. Goetz6, M. Golombek1, M. Grott3, T. Hudson1, C. Johnson9, G. Kargl10, N. Kobayashi11, J. Maki1, D. Mimoun12, A. Mocquet13, P. Morgan14, M. Panning15, W. T. Pike16, J. Tromp17, T. van Zoest18, R. Weber19, M. Wieczorek2 and the InSight Team, 1Jet Propulsion Laboratory, California Institute of Technology (bruce.banerdt@jpl..gov), 2Institut de Physique du Globe, Paris 3DLR Institute for Planetology, Berlin, 4Cornell Univ., 5Univ. Pierre et Marie Curie, Paris, 6Max Inst. for Solar System Studies, Lindau, 7Royal Observatory of Belgium, Brussels, 8ETH, Zurich, 9Univ. British Columbia, Vancouver, and Space Science Institute, 10Austrian Academy of Sciences, Vienna, 11JAXA, Tokyo, 12ISAE, Toulouse, 13Univ. Nantes, 14Northern Arizona Univ., Flagstaff, 15Univ. Florida, Gainesville, 16Imperial College, London, 17Princeton Univ., 18DLR Institute for Space Systems, Bremen, 19Marshall Space Flight Center.

Introduction: InSight was recently selected as the [1] is a six-component (3 Short Period and 3 Very- twelfth mission of NASA’s . It Broad-Band sensors) seismometer with careful thermal seeks to illuminate the fundamental processes of control, shielding from martian wind and temperature terrestrial planet formation and evolution by variations, and a sensitivity comparable to the best performing the first comprehensive surface-based terrestrial instruments across a frequency range of 1 geophysical investigation of Mars. It will provide key mHz to 50 Hz. HP3 [2] (Heat Flow and Physical information on the composition and structure of an Properties Package) is an instrumented self-hammering -like planet that has gone through of the mole system that will penetrate as deep as 5 m below evolutionary stages of the Earth up to, but not the surface, trailing a string of temperature sensors to including, plate tectonics. The traces of this history are measure the planetary heat flux through thermal still contained in the basic structural parameters of the gradient and conductivity measurements. planet: the size, state and composition of the core, the A key aspect of the mission is the use of a robotic composition and layering of the mantle, the thickness arm and a set of cameras to deploy the seismometer and layering of the crust, and the thermal flux from the and heat flow instruments to the ground, enabling these interior. instruments of perform their precise geophysical Science Goals: The scientific goals of InSight are measurements. In addition, InSight carries a set of to understand the formation and evolution of terrestrial atmospheric sensors to monitor the ambient air planets through investigation of the interior structure pressure, temperature and wind in order to separate and processes of Mars and to determine its present environmental noise from seismic signals. level of tectonic activity and impact flux. These goals A third investigations uses the spacecraft X-band will be realized through a specific set of basic communication system. RISE [3] (Rotation and scientific objectives: Interior Structure Experiment) will provide precision 1. Determine crust thickness and structure. tracking measurements of the rotation of Mars. Minute 2. Determine mantle composition and structure. variations in the magnitude and direction of the 3. Determine size, composition, and physical state planetary rotation vector can be related to the structure of the core. and properties of the core. 4. Determine thermal state of the interior. Flight System: The InSight flight system is based 5. Measure the rate and distribution of internal on a near-copy of the proven spacecraft, seismic activity. updated with modern avionics from and GRAIL. 6. Measure the rate of meteorite impacts on the All science requirements fit within established Phoenix surface. capabilities, with the exception of a full Mars year of These objectives have been rigorously and operations. This additional requirement is being quantitatively tied to mission, instrument and analysis addressed with minor changes to the power and capabilities, ensuring that InSight will provide a major thermal subsystems. advances in our understanding of planetary formation Mission Design: InSight will launch within a 20- and evolution. day window beginning March 8, 2016. After a 6½ Instrumentation: InSight will delineate these month cruise in a Type-1 trajectory, it will land in parameters for Mars with a focused set of western on September 20, 2016. After investigations centered on seismology and supported a 60-sol deployment phase, during which the by precision tracking and heat flow measurements. It seismometer and heat flow probe are placed on the carries two scientific instruments (see Figure 1). SEIS ground, the mole penetrates to its final depth, and all 44th Lunar and Planetary Science Conference (2013) 1915.pdf

the instruments are commissioned, the will radial variations in density and strength) and heat flow settle into a passive, repetitious observation phase (which can be related to the state of the core, the lasting 700 sols. The nominal end-of-mission is viscosity of the mantle, the distribution of radiogenic September 18, 2018. elements, etc.). Data will be relayed to Earth through orbiters Summary and Conclusions: The InSight mission (InSight can use any of MRO, Odyssey, , fills a longstanding gap in the scientific exploration of or MAVEN). A low-rate X-band DTE channel is the system [10, 11] by performing an in-situ available for commanding and data return in case of investigation of the interior of an Earth-like planet emergency. other than our own. It will provide unique and critical Single-Station Approach: There is a widely held, information about the fundamental processes of but erroneous, belief that multiple landers making terrestrial planet formation and evolution. simultaneous measurements (a network) are required References: [1] Lognonné et al. (2000), Planet. to address the objectives for understanding terrestrial Space Sci., 48, 1289-1302. [2] Grott et al. (2007) JGR, planet interiors. However comprehensive measure- 112, doi: 10.1029/2007JE002905. [3] Dehant et al. ments from a single geophysical station can be (2010) Planet. Space Sci., doi:10.1016/j.pss.2010.03. effectively used to determine the first-order divisions 014. [4] Vinnik et al. (2001) GRL, 28, 3031–3034. [5] of a terrestrial planet interior (crust, mantle, core). Lognonné and Johnson (2007), Treat. Geophys., 10, Rather than relying on a multi-station network to 69-122. [6] Roult and Romanowicz (1984), Bull. provide this information, InSight utilizes sophisticated Seism. Soc. Amer., 74, 2221–2243. [7] Lognonné et al. analysis techniques that are standard in terrestrial (1998), Geophys. J. Int., 135, 388-406. [8] Van Hoolst seismology, specific to single-station measurements, et al. (2003), Icarus, 161, 281-96. [9] Tsai (2010), Fall such as first motion analysis, receiver functions [4], AGU abs# U41A-05. [10] Banerdt et al. (2010), The surface wave dispersion [5], multiple surface wavetrain Rationale for a Long-lived Geophysical Network analysis [6], normal modes [7], tidal deformation [8], Mission to Mars, http://www8.nationalacademies.org/ and deconvolution and cross-correlation techniques ssbsurvey/publicview.aspx. [11] Vision and Voyages [9]. These results will be combined with measurements for Planetary Science in the Decade 2013-2022, of rotational variations (which are sensitive to deep http://www.nap.edu.

Robotic Arm

Medium-Gain Antennas SEIS Wind/Thermal Shield 3 HP

` Figure 1. The InSight lander showing deployed instruments.