MarsLS is a software tool for analyzing statistical dispersion of spacecraft-landing sites and displaying the results of its analyses. Originally intended for the Mars Explorer Rover (MER) mission, MarsLS is also applicable to landing sites on Earth and non-MER sites on Mars. MarsLS is a collection of interdependent MATLAB scripts that utilize the MATLAB graphical-user- interface software environment to display landing-site data (see figure) on calibrated image-maps of the Martian or other terrain. The landing- site data comprise latitude/longitude pairs generated by Monte Carlo runs of other computer programs that simulate entry, descent, and landing. Using these data, MarsLS can compute a landing-site ellipse — a standard means of depicting the area within which the spacecraft can be expected to land with a given probability. MarsLS incorporates several features for the user's convenience, including capabilities for drawing lines and ellipses, overlaying kilometer or latitude/longitude grids, drawing and/or specifying lines and/or points, entering notes, defining and/or displaying polygons to indicate hazards or areas of interest, and evaluating hazardous and/or scientifically interesting areas. As part of such an evaluation, MarsLS can compute the probability of landing in a specified polygonal area.
This program was written by Geoffrey Wawrzyniak, Brian Kennedy, Philip Knocke, and John Michel of Caltech for NASA's Jet Propulsion Laboratory. For further information, access the Technical Support Package (TSP) free on-line at www.techbriefs.com/tsp under the Software category.
This software is available for commercial licensing. Please contact Karina Edmonds of the California Institute of Technology at (626) 395-2322. Refer to NPO-35239.
This Brief includes a Technical Support Package (TSP).
Tool for Statistical Analysis and Display of Landing Sites
(reference NPO-35239) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA, specifically focusing on the development and analysis of landing sites for Mars Exploration Rovers (MER). It outlines the methodologies and tools used to assess landing footprints, which are critical for ensuring the safety and success of missions to Mars.
Key elements discussed include the trajectory analysis tools employed during the MER missions. Two primary programs were utilized: the Program to Optimize Simulated Trajectories (POST) developed at NASA Langley Research Center and the Atmospheric-Entry Powered Landing (AEPL) program from the Jet Propulsion Laboratory. Both programs relied on a shared aerodynamics database and atmospheric models to simulate the spacecraft's descent and landing dynamics. The POST program, in particular, modeled the spacecraft's descent using both six degrees of freedom (6DOF) dynamics during hypersonic entry and three degrees of freedom (3DOF) dynamics from parachute deployment to landing.
The document emphasizes the importance of landing site selection, which involved a comprehensive assessment of various factors, including scientific merit, flight system limitations, and safety considerations. The selection process aimed to identify target landing points that would avoid hazardous areas while maximizing the potential for scientific discovery. The landing dispersion calculations were crucial in determining the accuracy of the spacecraft's entry state relative to Mars, which was influenced by navigation uncertainties and maneuver execution errors.
Additionally, the document highlights the operational aspects of the MER missions, detailing the sequence of events from launch to landing. This included trajectory correction maneuvers to ensure precise entry conditions, the deployment of a parachute at approximately 7.5 km altitude, and the use of airbags to cushion the lander's touchdown. The successful landing of the Opportunity rover in Meridiani Planum on January 25, 2004, is noted as a significant achievement of the mission.
Overall, the document serves as a comprehensive overview of the technical and operational considerations involved in the MER missions, showcasing the advanced analytical tools and methodologies that contributed to the successful exploration of Mars. It underscores NASA's commitment to leveraging innovative technologies for future space exploration endeavors.
