Habitable Exoplanet Imager Optical- Mechanical Design and Analysis Printing: Jonathan Gaskins – University of North Carolina at Charlotte This poster is 48” wide by 36” high. Mentor: H. Philip Stahl– ST-10 It’s designed to be printed on a large ABSTRACT METHODS RESULTS Customizing the Content: The placeholders in this The Habitable Exoplanet Imager (HabEx) is a space • Utilized PATRAN for finite element modeling and formatted for you. telescope currently in development whose mission preprocessing includes finding and spectroscopically characterizing placeholders to add text, or click • Modeled and meshed JPL Spacecraft BUS exoplanets. Effective high-contrast imaging requires • Integrated various design modifications into full an icon to add a table, chart, tight stability requirements of the mirrors to prevent finite element model (FEM) issues such as line of sight and wavefront errors. SmartArt graphic, picture or PATRAN and NASTRAN were used to model updates in multimedia file. the design of the HabEx telescope and find how those updates affected stability. Most of the structural T modifications increased first mode frequencies and 1% Structural Damping LOS Displacement Values improved line of sight errors. These studies will be from text, just click the Bullets used to help define the baseline HabEx telescope button on the Home tab. design. If you need more placeholders for titles, JPL Spacecraft BUS Mesh make a copy of what you need and Concept for Baseline HabEx Design drag it into place. PowerPoint’s Smart Guides will help you align it 0.05% Structural Damping LOS Displacement Values with everything else. First peaks of X,Y, and Z displacements are at 32.3 Hz. BACKGROUND The X displacement values for 1% and 0.05% damping Want to use your own pictures respectively are 6.4𝜇𝑚 and 15𝜇𝑚. Displacement values for Y respectively are 9.3𝜇𝑚 and 41𝜇𝑚. instead of ours? No problem! Just Science Behind HabEx Technical Requirements Displacement for Z respectively are 1.7𝜇𝑚 and 7.5 𝜇𝑚. right • Exoplanets are difficult to directly image due to FIRST MODE FREQUENCY OF PRIMARY their home star’s glare which can be billions of Mount Location vs First Mode Frequency MIRROR ASSEMBLY VS TUBE DIAMTER Change Picture. Maintain the times brighter than the planet’s reflected light 70 60 )z 65 H 50 ( yc 60 )ZH proportion of pictures as you resize • Blocking the light from the star is possible with a ne ( Q 40 uq 55 ER e F coronagraph rF e 50 EDO 30 by dragging a corner. do M M 45 T 20 t SR sr 40 IF • The coronagraph has tight stability tolerances for iF 10 35 40 50 60 70 80 90 100 110 0 the optical surfaces 0 0.05 0.1 0.15 0.2 0.25 0.3 Mount Location (%) TUBE DIAMTER (METERS) • Technical challenges involve creating a telescope which is stiff enough to prevent deflections of the Full Finite Element Model, Wireframe (left) primary mirror in the realm of nanometers and Shaded (right) • Utilized NASTRAN to perform dynamic and modal analyses • Using a prepared MATLAB script, performed line of sight and jitter calculations • Used a prepared Excel Workbook for applying First mode of optical tower assembly at 28 Hz (left), First isolation filters to data mode of primary mirror assembly 33Hz (middle) Second • Finite element model of the full assembly was mode of primary mirror assembly at 34Hz (right) constantly changing throughout the analysis process CONCLUSIONS • A more rigid Spacecraft BUS leads to improved OBJECTIVES RESULTS optical stability by an order of magnitude for some first peaks • Changing from 1% to 0.05% structural damping does • Integrate JPL Spacecraft BUS • Found that the “rigid” representation of the not increase displacements and rotations by large Spacecraft BUS created better LOS and jitter • Explore differences in “rigid” and flexible Spacecraft orders of magnitude behaviors BUS • Tilt in the primary mirror dynamic surface figure • Changing from 1% damping to 0.05% damping • Find jitter and line of sight differences in changing error needs to be removed changed displacements rotations by a factor of from 1% to 0.05% linear structural damping • A new MATLAB code needs to be run for the around 14 in the worst cases for the first few peaks • Find how to calculate primary mirror dynamic microthruster disturbance data • Created a NASTRAN SOL 111 file (modal frequency surface figure error • Support structure levels off at a first modal response) which tracked the primary mirror nodes to • Find how to make primary mirror assembly stiffer. frequency of ~50Hz for tubes 20cm (8in) in diameter. find the dynamic surface figure error Tube diameter of the support structure should be The stiffness of the structure may not improve with • Explored mounting locations of the primary mirror explored to see if larger stiffer tubes create higher larger tube diameters due to the members of the and found an optimal mounting location for the first mode frequencies of the primary mirror structure approaching their maximum stiffness current support structure design at 65% mount assembly. Mount locations should be explored. AKNOWLEDGMENTS location. Mount location is referred to as percentage radial Thanks to my mentor Phil Stahl for helping me become part of distance from the edge (edge mounting is 100%) • Created a new FEM to be used in the future for this optics community and giving me help where needed. calculating microthruster disturbances • Find the dynamic response to reaction wheel Thanks to Jay Garcia in the Advanced Concepts Office for disturbances versus micro-thruster disturbances teaching me about structural analysis and engineering everyday.