1St – University of Kansas

Total Page:16

File Type:pdf, Size:1020Kb

1St – University of Kansas Pluto Research Orbiter Studying Experimental Rocket Propulsion for Improving trans-Neptunian Exploration University of Kansas Team: AstroHawks Jordan Alonzo Frank Bonet III Jack Cozzi Taylor George Miranda Myer James Peters Nathaniel Routh Bradley Schroeder Joseph Vincent Luke Wehrkamp University of Kansas Team: Supervisor Dr. Mark Ewing May 10, 2018 Acknowledgements Firstly, the AstroHawks would like to express their gratitude to the people who were consulted and who provided invaluable help throughout the design process of PROSERPINE. University of Kansas • George Blake • Dr. Steve Hawley • Dr. Crag McLaughlin • Bailey Miller • Arno Prinsloo • Alex Sizemore • Sam Yang Industry • Michael Altenhofen (SpaceX) • Tiffany Finley (Southwest Research Institute) • Steve Mance (SpaceX) • Dr. Jerry Manwiler (Fundamental Technologies) • Adam Sexton (Ball Aerospace) • Dr. Kelsi Singer (Southwest Research Institute) Secondly, the AstroHawks would like to express their gratitude to the families, friends, and significant others who provided much-needed support throughout the design process of PROSERPINE. Thirdly, the AstroHawks would like to express their gratitude to Piper. Continuously brightening everyone’s day, your puppy-dog eyes, generous amounts of kisses, and contagious energy were fundamental to the success of PROSERPINE. Department of Aerospace Engineering i University of Kansas Team: AstroHawks Department of Aerospace Engineering ii Table of Contents 1. MISSION DESCRIPTION ................................................................................................................................. 1 2. EXECUTIVE SUMMARY ................................................................................................................................ 2 3. HISTORY ........................................................................................................................................................... 5 4. SCIENTIFIC OBJECTIVES AND INSTRUMENTS ........................................................................................ 8 4.1 Downselection ............................................................................................................................................. 8 4.2 Scientific Objectives .................................................................................................................................... 8 4.2.1 Terrain of Pluto ..................................................................................................................................... 8 4.2.2 Atmosphere of Pluto ........................................................................................................................... 10 4.2.3 Orbital Mechanics of Pluto-Charon System ....................................................................................... 11 4.2.4 Moons of Pluto ................................................................................................................................... 12 4.2.5 Planetary Flybys en Route to Pluto .................................................................................................... 13 4.3 Science Instruments ................................................................................................................................... 14 4.3.1 Europa Imaging System ...................................................................................................................... 14 4.3.2 Radar for Europa Assessment and Sounding: Ocean to Near-Surface ............................................... 14 4.3.3 Submillimeter Wave Array Spectrometer ........................................................................................... 15 4.3.4 Magnetometers ................................................................................................................................... 15 4.3.5 Solar Wind Ion Analyzer .................................................................................................................... 16 4.3.6 Mass Spectrometer for Planetary Exploration .................................................................................... 17 4.3.7 Ultraviolet Imaging Spectrometer/Spectrograph ................................................................................ 17 4.3.8 Europa Thermal Emission Imaging System ....................................................................................... 17 4.4 Summary .................................................................................................................................................... 18 5. TRAJECTORY ................................................................................................................................................. 19 5.1 Launch ....................................................................................................................................................... 19 5.2 Interplanetary Flight Path .......................................................................................................................... 21 5.2.1 Downselection .................................................................................................................................... 21 5.2.2 Simulation ........................................................................................................................................... 23 5.2.3 Results ................................................................................................................................................ 24 5.3 Deceleration ............................................................................................................................................... 25 5.4 Mission Operations .................................................................................................................................... 28 5.4.1 Circularization .................................................................................................................................... 28 5.4.2 Mapping .............................................................................................................................................. 28 5.4.3 Moon Rendezvous .............................................................................................................................. 28 5.4.4 End-of-Life ......................................................................................................................................... 29 5.4.5 Simulation and Results ....................................................................................................................... 29 6. PROPULSION SYSTEM ................................................................................................................................. 30 Department of Aerospace Engineering iii 6.1 Limiting Factors ......................................................................................................................................... 30 6.2 Possibilities ................................................................................................................................................ 30 6.2.1 Chemical Propulsion ........................................................................................................................... 30 6.2.2 Nuclear Thermal Propulsion ............................................................................................................... 31 6.2.3 Electric Propulsion ............................................................................................................................. 31 6.3 Downselection ........................................................................................................................................... 33 6.3.1 Criteria ................................................................................................................................................ 33 6.3.2 Results ................................................................................................................................................ 34 6.4 Configuration ............................................................................................................................................. 36 6.4.1 Xenon Storage .................................................................................................................................... 36 6.4.2 Ion Thruster ........................................................................................................................................ 37 6.4.3 Power System ..................................................................................................................................... 37 6.4.4 System Layout .................................................................................................................................... 37 7. POWER SYSTEM ............................................................................................................................................ 39 7.1 Power Budget ............................................................................................................................................ 39 7.2 Downselection ........................................................................................................................................... 41 7.3 Kilopower Reactor Using Stirling Technology (KRUSTY) ...................................................................... 41 7.4 Batteries ....................................................................................................................................................
Recommended publications
  • Mission to Jupiter
    This book attempts to convey the creativity, Project A History of the Galileo Jupiter: To Mission The Galileo mission to Jupiter explored leadership, and vision that were necessary for the an exciting new frontier, had a major impact mission’s success. It is a book about dedicated people on planetary science, and provided invaluable and their scientific and engineering achievements. lessons for the design of spacecraft. This The Galileo mission faced many significant problems. mission amassed so many scientific firsts and Some of the most brilliant accomplishments and key discoveries that it can truly be called one of “work-arounds” of the Galileo staff occurred the most impressive feats of exploration of the precisely when these challenges arose. Throughout 20th century. In the words of John Casani, the the mission, engineers and scientists found ways to original project manager of the mission, “Galileo keep the spacecraft operational from a distance of was a way of demonstrating . just what U.S. nearly half a billion miles, enabling one of the most technology was capable of doing.” An engineer impressive voyages of scientific discovery. on the Galileo team expressed more personal * * * * * sentiments when she said, “I had never been a Michael Meltzer is an environmental part of something with such great scope . To scientist who has been writing about science know that the whole world was watching and and technology for nearly 30 years. His books hoping with us that this would work. We were and articles have investigated topics that include doing something for all mankind.” designing solar houses, preventing pollution in When Galileo lifted off from Kennedy electroplating shops, catching salmon with sonar and Space Center on 18 October 1989, it began an radar, and developing a sensor for examining Space interplanetary voyage that took it to Venus, to Michael Meltzer Michael Shuttle engines.
    [Show full text]
  • Visit the National Academies Press Online, the Authoritative Source
    Assessment of the CRAF and Cassini Science Missions: Letter Report Committee on Planetary and Lunar Exploration, Space Science Board, Commission on Physical Sciences, Mathematics, and Resources, National Research Council ISBN: 0-309-12299-6, 7 pages, 8 1/2 x 11, (1988) This free PDF was downloaded from: http://www.nap.edu/catalog/12334.html Visit the National Academies Press online, the authoritative source for all books from the National Academy of Sciences, the National Academy of Engineering, the Institute of Medicine, and the National Research Council: • Download hundreds of free books in PDF • Read thousands of books online, free • Sign up to be notified when new books are published • Purchase printed books • Purchase PDFs • Explore with our innovative research tools Thank you for downloading this free PDF. If you have comments, questions or just want more information about the books published by the National Academies Press, you may contact our customer service department toll-free at 888-624-8373, visit us online, or send an email to [email protected]. This free book plus thousands more books are available at http://www.nap.edu. Copyright © National Academy of Sciences. Permission is granted for this material to be shared for noncommercial, educational purposes, provided that this notice appears on the reproduced materials, the Web address of the online, full authoritative version is retained, and copies are not altered. To disseminate otherwise or to republish requires written permission from the National Academies Press. Space Studies Board Jump to Search: Top NewsJump to Science in the Subscribe to our FREE e- Headlines newsletter! NATIONAL ACADEMY OF SCIENCES NATIONAL ACADEMY OF ENGINEERING INSTITUTE OF MEDICINE NATIONAL RESEARCH COUNCIL June 18, 2004 Current Operating Status Assessment of the CRAF and Cassini Science Missions: Letter Report http://www.nap.edu/catalog/12334.html On September 1, 1988, Dr.
    [Show full text]
  • Les Opéras De Lully Remaniés Par Rebel Et Francœur Entre 1744 Et 1767 : Héritage Ou Modernité ? Pascal Denécheau
    Les opéras de Lully remaniés par Rebel et Francœur entre 1744 et 1767 : héritage ou modernité ? Pascal Denécheau To cite this version: Pascal Denécheau. Les opéras de Lully remaniés par Rebel et Francœur entre 1744 et 1767 : héritage ou modernité ? : Deuxième séminaire de recherche de l’IRPMF : ”La notion d’héritage dans l’histoire de la musique”. 2007. halshs-00437641 HAL Id: halshs-00437641 https://halshs.archives-ouvertes.fr/halshs-00437641 Preprint submitted on 1 Dec 2009 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. P. Denécheau : « Les opéras de Lully remaniés par Rebel et Francœur : héritage ou modernité ? » Les opéras de Lully remaniés par Rebel et Francœur entre 1744 et 1767 : héritage ou modernité ? Une grande partie des œuvres lyriques composées au XVIIe siècle par Lully et ses prédécesseurs ne se sont maintenues au répertoire de l’Opéra de Paris jusqu’à la fin du siècle suivant qu’au prix d’importants remaniements : les scènes jugées trop longues ou sans lien avec l’action principale furent coupées, quelques passages réécrits, un accompagnement de l’orchestre ajouté là où la voix n’était auparavant soutenue que par le continuo.
    [Show full text]
  • Constellation Program Overview
    Constellation Program Overview October 2008 hris Culbert anager, Lunar Surface Systems Project Office ASA/Johnson Space Center Constellation Program EarthEarth DepartureDeparture OrionOrion -- StageStage CrewCrew ExplorationExploration VehicleVehicle AresAres VV -- HeavyHeavy LiftLift LaunchLaunch VehicleVehicle AltairAltair LunarLunar LanderLander AresAres II -- CrewCrew LaunchLaunch VehicleVehicle Lunar Capabilities Concept Review EstablishedEstablished Lunar Lunar Transportation Transportation EstablishEstablish Lunar Lunar Surface SurfaceArchitecturesArchitectures ArchitectureArchitecture Point Point of of Departure: Departure: StrategiesStrategies which: which: Satisfy NASA NGO’s to acceptable degree ProvidesProvides crew crew & & cargo cargo delivery delivery to to & & from from the the Satisfy NASA NGO’s to acceptable degree within acceptable schedule moonmoon within acceptable schedule Are consistent with capacity and capabilities ProvidesProvides capacity capacity and and ca capabilitiespabilities consistent consistent Are consistent with capacity and capabilities withwith candidate candidate surface surface architectures architectures ofof the the transportation transportation systems systems ProvidesProvides sufficient sufficient performance performance margins margins IncludeInclude set set of of options options fo for rvarious various prioritizations prioritizations of cost, schedule & risk RemainsRemains within within programmatic programmatic constraints constraints of cost, schedule & risk ResultsResults in in acceptable
    [Show full text]
  • An Impacting Descent Probe for Europa and the Other Galilean Moons of Jupiter
    An Impacting Descent Probe for Europa and the other Galilean Moons of Jupiter P. Wurz1,*, D. Lasi1, N. Thomas1, D. Piazza1, A. Galli1, M. Jutzi1, S. Barabash2, M. Wieser2, W. Magnes3, H. Lammer3, U. Auster4, L.I. Gurvits5,6, and W. Hajdas7 1) Physikalisches Institut, University of Bern, Bern, Switzerland, 2) Swedish Institute of Space Physics, Kiruna, Sweden, 3) Space Research Institute, Austrian Academy of Sciences, Graz, Austria, 4) Institut f. Geophysik u. Extraterrestrische Physik, Technische Universität, Braunschweig, Germany, 5) Joint Institute for VLBI ERIC, Dwingelo, The Netherlands, 6) Department of Astrodynamics and Space Missions, Delft University of Technology, The Netherlands 7) Paul Scherrer Institute, Villigen, Switzerland. *) Corresponding author, [email protected], Tel.: +41 31 631 44 26, FAX: +41 31 631 44 05 1 Abstract We present a study of an impacting descent probe that increases the science return of spacecraft orbiting or passing an atmosphere-less planetary bodies of the solar system, such as the Galilean moons of Jupiter. The descent probe is a carry-on small spacecraft (< 100 kg), to be deployed by the mother spacecraft, that brings itself onto a collisional trajectory with the targeted planetary body in a simple manner. A possible science payload includes instruments for surface imaging, characterisation of the neutral exosphere, and magnetic field and plasma measurement near the target body down to very low-altitudes (~1 km), during the probe’s fast (~km/s) descent to the surface until impact. The science goals and the concept of operation are discussed with particular reference to Europa, including options for flying through water plumes and after-impact retrieval of very-low altitude science data.
    [Show full text]
  • PDS Mission Interface for Europa Mission Status of Planning for Data Archiving
    PDS Mission Interface for Europa Mission Status of Planning for Data Archiving CARTOGRAPHY AND IMAGING SCIENCES (“Imaging”) NODE PDS Lead Node Lisa Gaddis (USGS, Astrogeology) August 2016 Overview Common goals PDS4 Archiving roles, responsibilities EM archiving deliverables Data and Archive Working Group (DAWG) Archiving assignments Archiving activities to date Archiving schedule Current archiving activities Where we are now August 2016 2 Common Goals The PDS and Europa Mission (EM) will work together to ensure that we Organize, document and format EM digital planetary data in a standardized manner Collect complete, well-documented, peer-reviewed planetary data into archives Make planetary data available and useful to the science community ○ Provide online data delivery tools & services Ensure the long-term preservation and usability of the data August 2016 3 PDS4 The new PDS, an integrated data system to improve access ○ Required for all missions (e.g., used by LADEE, MAVEN) A re-architected, modern, online data system ○ Data are organized into bundles Includes all data for a particular instrument (e.g., PDF/A documents) ○ Bundles have collections Grouped files with a similar origin (e.g., Document Collection) Improves efficiency of ingestion and distribution of data ○ Uses Extensible Markup Language (XML) and standard data format templates ○ Self-consistent information model & software system ○ Information for Data Providers https://pds.nasa.gov/pds4/about ○ PDS4 Concepts Document https://pds.nasa.gov/pds4/doc/concepts/Concepts_150909.pdf
    [Show full text]
  • + New Horizons
    Media Contacts NASA Headquarters Policy/Program Management Dwayne Brown New Horizons Nuclear Safety (202) 358-1726 [email protected] The Johns Hopkins University Mission Management Applied Physics Laboratory Spacecraft Operations Michael Buckley (240) 228-7536 or (443) 778-7536 [email protected] Southwest Research Institute Principal Investigator Institution Maria Martinez (210) 522-3305 [email protected] NASA Kennedy Space Center Launch Operations George Diller (321) 867-2468 [email protected] Lockheed Martin Space Systems Launch Vehicle Julie Andrews (321) 853-1567 [email protected] International Launch Services Launch Vehicle Fran Slimmer (571) 633-7462 [email protected] NEW HORIZONS Table of Contents Media Services Information ................................................................................................ 2 Quick Facts .............................................................................................................................. 3 Pluto at a Glance ...................................................................................................................... 5 Why Pluto and the Kuiper Belt? The Science of New Horizons ............................... 7 NASA’s New Frontiers Program ........................................................................................14 The Spacecraft ........................................................................................................................15 Science Payload ...............................................................................................................16
    [Show full text]
  • Mscthesis Joseangelgutier ... Humada.Pdf
    Targeting a Mars science orbit from Earth using Dual Chemical-Electric Propulsion and Ballistic Capture Jose Angel Gutierrez Ahumada Delft University of Technology TARGETING A MARS SCIENCE ORBIT FROM EARTH USING DUAL CHEMICAL-ELECTRIC PROPULSION AND BALLISTIC CAPTURE by Jose Angel Gutierrez Ahumada MSc Thesis in partial fulfillment of the requirements for the degree of Master of Science in Aerospace Engineering at the Delft University of Technology, to be defended publicly on Wednesday May 8, 2019. Supervisor: Dr. Francesco Topputo, TU Delft/Politecnico di Milano Dr. Ryan Russell, The University of Texas at Austin Thesis committee: Dr. Francesco Topputo, TU Delft/Politecnico di Milano Prof. dr. ir. Pieter N.A.M. Visser, TU Delft ir. Ron Noomen, TU Delft Dr. Angelo Cervone, TU Delft This thesis is confidential and cannot be made public until December 31, 2020. An electronic version of this thesis is available at http://repository.tudelft.nl/. Cover picture adapted from https://steemitimages.com/p/2gs...QbQvi EXECUTIVE SUMMARY Ballistic capture is a relatively novel concept in interplanetary mission design with the potential to make Mars and other targets in the Solar System more accessible. A complete end-to-end interplanetary mission from an Earth-bound orbit to a stable science orbit around Mars (in this case, an areostationary orbit) has been conducted using this concept. Sets of initial conditions leading to ballistic capture are generated for different epochs. The influence of the dynamical model on the capture is also explored briefly. Specific capture trajectories are then selected based on a study of their stabilization into an areostationary orbit.
    [Show full text]
  • Westminsterresearch the Astrobiology Primer V2.0 Domagal-Goldman, S.D., Wright, K.E., Adamala, K., De La Rubia Leigh, A., Bond
    WestminsterResearch http://www.westminster.ac.uk/westminsterresearch The Astrobiology Primer v2.0 Domagal-Goldman, S.D., Wright, K.E., Adamala, K., de la Rubia Leigh, A., Bond, J., Dartnell, L., Goldman, A.D., Lynch, K., Naud, M.-E., Paulino-Lima, I.G., Kelsi, S., Walter-Antonio, M., Abrevaya, X.C., Anderson, R., Arney, G., Atri, D., Azúa-Bustos, A., Bowman, J.S., Brazelton, W.J., Brennecka, G.A., Carns, R., Chopra, A., Colangelo-Lillis, J., Crockett, C.J., DeMarines, J., Frank, E.A., Frantz, C., de la Fuente, E., Galante, D., Glass, J., Gleeson, D., Glein, C.R., Goldblatt, C., Horak, R., Horodyskyj, L., Kaçar, B., Kereszturi, A., Knowles, E., Mayeur, P., McGlynn, S., Miguel, Y., Montgomery, M., Neish, C., Noack, L., Rugheimer, S., Stüeken, E.E., Tamez-Hidalgo, P., Walker, S.I. and Wong, T. This is a copy of the final version of an article published in Astrobiology. August 2016, 16(8): 561-653. doi:10.1089/ast.2015.1460. It is available from the publisher at: https://doi.org/10.1089/ast.2015.1460 © Shawn D. Domagal-Goldman and Katherine E. Wright, et al., 2016; Published by Mary Ann Liebert, Inc. This Open Access article is distributed under the terms of the Creative Commons Attribution Noncommercial License (http://creativecommons.org/licenses/by- nc/4.0/) which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited. The WestminsterResearch online digital archive at the University of Westminster aims to make the research output of the University available to a wider audience.
    [Show full text]
  • Silencing Nasa's Space Shuttle Crawler
    SILENCING NASA’S SPACE SHUTTLE CRAWLER TRANSPORTER R. MacDonalda, C. Faszerb, and R. Margasahayamc aNoise Solutions Inc., #310 605 – 1st Street SW, Calgary, Alberta, Canada T2P 3S9 bFaszer Farquharson & Associates, #304 605 – 1st Street SW, Calgary, Alberta, Canada T2P 3S9 cNASA, John F. Kennedy Space Center, Florida, United States of America 32899 [email protected]; [email protected]; [email protected] Abstract. The crawler transporter (CT) is the world’s second largest known tracked vehicle, weighing 6 million pounds with a length of 131 feet and a width of 113 feet. The Kennedy Space Center (KSC) has two CTs that were designed and built for the Apollo program in the 1960’s, maintained and retrofitted for use in the Space Shuttle program. As a key element of the Space Shuttle ground systems, the crawler transports the entire 12-million-pound stack comprising the orbiter, the mobile launch platform (MLP), the external tank (ET), and the solid rocket boosters (SRB) from the Vehicle Assembly Building (VAB) to the launch pad. This rollout, constituting a 3.5 to 5.0 mile journey at a top speed of 0.9 miles-per-hour, requires over 8 hours to reach either Launch Complex 39A or B. This activity is only a prelude to the spectacle of sound and fury of the Space Shuttle launch to orbit in less than 10 minutes and traveling at orbital velocities of Mach 24. This paper summarizes preliminary results from the Crawler Transporter Sound Attenuation Study, encompassing test and engineering analysis of significant sound sources to measure and record full frequency spectrum and intensity of the various noise sources and to analyze the potential for noise mitigation.
    [Show full text]
  • Space Sector Brochure
    SPACE SPACE REVOLUTIONIZING THE WAY TO SPACE SPACECRAFT TECHNOLOGIES PROPULSION Moog provides components and subsystems for cold gas, chemical, and electric Moog is a proven leader in components, subsystems, and systems propulsion and designs, develops, and manufactures complete chemical propulsion for spacecraft of all sizes, from smallsats to GEO spacecraft. systems, including tanks, to accelerate the spacecraft for orbit-insertion, station Moog has been successfully providing spacecraft controls, in- keeping, or attitude control. Moog makes thrusters from <1N to 500N to support the space propulsion, and major subsystems for science, military, propulsion requirements for small to large spacecraft. and commercial operations for more than 60 years. AVIONICS Moog is a proven provider of high performance and reliable space-rated avionics hardware and software for command and data handling, power distribution, payload processing, memory, GPS receivers, motor controllers, and onboard computing. POWER SYSTEMS Moog leverages its proven spacecraft avionics and high-power control systems to supply hardware for telemetry, as well as solar array and battery power management and switching. Applications include bus line power to valves, motors, torque rods, and other end effectors. Moog has developed products for Power Management and Distribution (PMAD) Systems, such as high power DC converters, switching, and power stabilization. MECHANISMS Moog has produced spacecraft motion control products for more than 50 years, dating back to the historic Apollo and Pioneer programs. Today, we offer rotary, linear, and specialized mechanisms for spacecraft motion control needs. Moog is a world-class manufacturer of solar array drives, propulsion positioning gimbals, electric propulsion gimbals, antenna positioner mechanisms, docking and release mechanisms, and specialty payload positioners.
    [Show full text]
  • Multi-Body Trajectory Design Strategies Based on Periapsis Poincaré Maps
    MULTI-BODY TRAJECTORY DESIGN STRATEGIES BASED ON PERIAPSIS POINCARÉ MAPS A Dissertation Submitted to the Faculty of Purdue University by Diane Elizabeth Craig Davis In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy August 2011 Purdue University West Lafayette, Indiana ii To my husband and children iii ACKNOWLEDGMENTS I would like to thank my advisor, Professor Kathleen Howell, for her support and guidance. She has been an invaluable source of knowledge and ideas throughout my studies at Purdue, and I have truly enjoyed our collaborations. She is an inspiration to me. I appreciate the insight and support from my committee members, Professor James Longuski, Professor Martin Corless, and Professor Daniel DeLaurentis. I would like to thank the members of my research group, past and present, for their friendship and collaboration, including Geoff Wawrzyniak, Chris Patterson, Lindsay Millard, Dan Grebow, Marty Ozimek, Lucia Irrgang, Masaki Kakoi, Raoul Rausch, Matt Vavrina, Todd Brown, Amanda Haapala, Cody Short, Mar Vaquero, Tom Pavlak, Wayne Schlei, Aurelie Heritier, Amanda Knutson, and Jeff Stuart. I thank my parents, David and Jeanne Craig, for their encouragement and love throughout my academic career. They have cheered me on through many years of studies. I am grateful for the love and encouragement of my husband, Jonathan. His never-ending patience and friendship have been a constant source of support. Finally, I owe thanks to the organizations that have provided the funding opportunities that have supported me through my studies, including the Clare Booth Luce Foundation, Zonta International, and Purdue University and the School of Aeronautics and Astronautics through the Graduate Assistance in Areas of National Need and the Purdue Forever Fellowships.
    [Show full text]