Emily Lakdawalla Read online

  The Design and Engineering of

  CURIOSITY

  How the Mars Rover Performs Its Job

  Emily Lakdawalla

  The Design and Engineering of Curiosity

  How the Mars Rover Performs Its Job

  Emily Lakdawal a

  The Design

  and Engineering

  of Curiosity

  How the Mars Rover Performs Its Job

  Emily Lakdawalla

  The Planetary Society

  Pasadena, CA, USA

  SPRINGER-PRAXIS BOOKS IN SPACE EXPLORATION

  Springer Praxis Books

  ISBN

  978-3-319-68144-3 ISBN

  978-3-319-68146-7 (eBook)

  https://doi.org/10.1007/978-3-319-68146-7

  Library of Congress Control Number: 2017963344

  © Springer International Publishing AG, part of Springer Nature 2018

  This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way, and transmission or information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed.

  The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use.

  The publisher, the authors and the editors are safe to assume that the advice and information in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. The publisher remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

  Cover design: Jim Wilkie

  Project Editor: David M. Harland

  Printed on acid-free paper

  This Springer imprint is published by the registered company Springer International Publishing AG part of Springer Nature.

  The registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland

  Contents

  Dedication .................................................................................................................. viii Foreword .................................................................................................................... ix Acknowledgments ..................................................................................................... xi Preface ........................................................................................................................ xiii

  1 Mars Science Laboratory ................................................................................... 1

  1.1

  Introduction ................................................................................................. 1

  1.2 Designing a Bigger Lander (2000–2003) ................................................... 2

  1.3 Becoming Mars Science Laboratory (2003–2004) ..................................... 8

  1.4

  Preliminary Design (2005–2006) ................................................................ 16

  1.5 The Cost of Complexity (2007–2008) ........................................................ 24

  1.6

  A Two-Year Respite (2009–2010) .............................................................. 39

  1.7

  Final Preparations (2010–2011) .................................................................. 42

  1.8

  References ................................................................................................... 54

  2 Getting to Mars ................................................................................................... 57

  2.1

  Launch ......................................................................................................... 57

  2.2

  Cruise .......................................................................................................... 61

  2.3

  EDL: Entry, Descent, and Landing ............................................................. 66

  2.4

  Curiosity on Mars ....................................................................................... 101

  2.5 Epilogue: Views of the Cruise Hardware .................................................... 104

  2.6

  References ................................................................................................... 107

  3 Mars Operations ................................................................................................. 110

  3.1

  Introduction ................................................................................................. 110

  3.2

  Mars’ Calendar ............................................................................................ 110

  3.3 Strategic, Supratactical, and Tactical Planning ........................................... 114

  v

  vi Contents

  3.4

  Tactical Planning Process............................................................................ 115

  3.5

  Mission Summary ....................................................................................... 118

  3.6

  References ................................................................................................... 137

  4 How the Rover Works ......................................................................................... 138

  4.1

  Introduction ................................................................................................. 138

  4.2 Power System and MMRTG ....................................................................... 138

  4.3

  Avionics ...................................................................................................... 145

  4.4

  Thermal Control .......................................................................................... 148

  4.5 Telecommunication ..................................................................................... 154

  4.6

  Mobility System .......................................................................................... 162

  4.7

  Testbeds ....................................................................................................... 178

  4.8

  References ................................................................................................... 182

  5 SA/SPaH: Sample Acquisition, Processing, and Handling .............................. 185

  5.1

  Introduction ................................................................................................. 185

  5.2 Robotic Arm and Turret .............................................................................. 185

  5.3

  The Drill ...................................................................................................... 189

  5.4 CHIMRA: Collection and Handling for In Situ Martian

  Rock Analysis ..........................................................
................................... 196

  5.5

  DRT: Dust Removal Tool ............................................................................ 209

  5.6

  Organic Check Material .............................................................................. 211

  5.7

  Sample Playground ..................................................................................... 213

  5.8 Sam and CheMin Inlets and Wind Guards .................................................. 217

  5.9

  References ................................................................................................... 220

  6 The Mast, Engineering Cameras, Navigation, and Hazard Avoidance .......... 221

  6.1

  Introduction ................................................................................................. 221

  6.2

  Remote Sensing Mast ................................................................................. 221

  6.3 Engineering Cameras: Navcams and Hazcams ........................................... 224

  6.4 Using the Engineering Cameras .................................................................. 227

  6.5

  Rover Driving .............................................................................................. 230

  6.6

  References ................................................................................................... 233

  7 Curiosity’s Science Cameras .............................................................................. 234

  7.1

  Introduction ................................................................................................. 234

  7.2

  Mastcam ...................................................................................................... 234

  7.3

  MARDI: Mars Descent Imager ................................................................... 252

  7.4

  MAHLI: Mars Hand Lens Imager .............................................................. 256

  7.5

  References ................................................................................................... 273

  8 Curiosity’s Environmental Sensing Instruments ............................................. 275

  8.1

  Introduction ................................................................................................. 275

  8.2 RAD: Radiation Assessment Detector ........................................................ 275

  8.3

  DAN: Dynamic Albedo of Neutrons .......................................................... 280

  8.4

  REMS: Rover Environmental Monitoring Station ...................................... 285

  8.5

  References ................................................................................................... 292

  Contents vii

  9 Curiosity’s Chemistry Instruments ................................................................... 294

  9.1

  Introduction ................................................................................................. 294

  9.2 ChemCam ................................................................................................... 294

  9.3

  APXS: Alpha Particle X-Ray Spectrometer ............................................... 308

  9.4 CheMin: Chemistry and Mineralogy .......................................................... 318

  9.5

  SAM: Sample Analysis at Mars .................................................................. 327

  9.6

  References ................................................................................................... 346

  Epilogue: Back on Earth .......................................................................................... 349

  Appendix: Curiosity Activity Summary ................................................................. 352

  About the Author....................................................................................................... 392

  Index ........................................................................................................................... 393

  Dedication

  For Anahita, who challenged me to be

  “a writer who writes a book”

  Foreword

  On the night of August 5th, 2012, I was sitting in my room watching a video stream from

  JPL’s Mission Control as the Curiosity rover descended toward Mars. As I watched, I

  sketched a comic about the Curiosity landing on my drawing tablet.

  I’ve often anthropomorphized our space robots in my comics. In one sense, this is silly.

  A rover like Curiosity is a piece of hardware. It’s a collection of motors, computers, and

  sensors. It can’t think or feel. Maybe, someday, a robot will blur the line between “machine”

  and a “thing with feelings,” but Curiosity isn’t that. It’s just a big, complicated car.

  But in another sense, anthropomorphizing these robots feels natural. It’s not that there’s

  some magic in the circuits. It’s that every single piece of hardware on Curiosity is the

  physical manifestation of years of planning by real people, sending it out to act on their

  behalf in the universe. The hardware carries with it our hopes and fears.

  When Curiosity touched down on Mars, I felt so proud of our robot. I wasn’t really

  proud of the mechanical actuators for actuating right. I was proud because I knew that each actuator, each spring, each wire, each sensor, and each line of code was lovingly crafted

  by someone. I knew all those people were watching along with me, all thinking, “I hope I

  did a good job.” And they did!

  While I was sitting in front of my computer that night, Emily was in the JPL press

  room. She had a front row seat to the action, and, through her Twitter feed, helped interpret what was going on for those of us at home.

  Emily is a space enthusiast’s space enthusiast and an incredible font of knowledge. A

  few years ago, I started wondering whether the photos taken by the new Juno spacecraft

  would be better than any of the ones from previous missions. After spending a few hours

  struggling to figure out how to compare the cameras on various spacecraft, I asked Emily

  for help. A moment later, she replied with an incredible spreadsheet she’d created listing

  every camera that had been sent into the outer solar system along with technical specifica-

  tions for each. It was exactly what I was looking for. Later, when I decided to include a

  diagram of the Curiosity rover in one of my books, I made sure to run it by her first, to find out which parts I got wrong and which cool details I missed.

  ix

  x Foreword

  In this book, she describes how Curiosity works. She gives a window into the hopes,

  fears, and improbable what-if scenarios embedded in each technical decision. To tell the

  story, she draws on published papers, internal documents, photograph archives, and her

  own conversations with members of the Curiosity team over the course of the mission. For

  anyone curious about Curiosity – if you wonder “why was it lowered from a sky crane?”

  or “what's that weird thing sticking off the side?” – then this is the book for you.

  Randall Munroe

  Author of What If?, Thing Explainer, and xkcd

  Acknowledgments

  This book would not exist without the generous assistance of numerous members of the

  Mars Science Laboratory team and the wider space science co
mmunity. In particular,

  Ashwin Vasavada kept me updated in frequent telephone conversations, replied quickly to

  countless emails, and read every word of the first draft. Guy Webster and Veronica

  McGregor helped me access JPL and its scientists and engineers and steered the book

  through sometimes painful export-control review. John Grotzinger welcomed me into the

  mission’s science team, and Jim Erickson trusted me to talk with engineers.

  A huge number of people contributed to this book through interviews, email correspon-

  dence, and/or technical reviews of book sections, including Ryan Anderson, Ray Arvidson,

  Magdy Bareh, Paolo Bellutta, Mike Caplinger, Fred Calef, Allen Chen, Steven Collins,

  Nagin Cox, Joy Crisp, Mark Dahl, Lauren Edgar, Ken Edgett, Chad Edwards, Doug

  Ellison, Abigail Fraeman, Travis Gabriel, Matt Golombek, Javier Gomez-Elvira, Peter

  Grindrod, Cambria Hanson, Craig Hardgrove, Matt Heverly, Sarah Hörst, Louise Jandura,

  Jason Kastner, Stephen Kuhn, Danny Lam, Steve Lee, Mark Lemmon, Dan Limonadi,

  Maxim Litvak, Paul Mahaffy, Charles Malespin, Mike Malin, Rob Manning, Scott

  Maxwell, Sarah Milkovich, Andy Mishkin, Jeff Moersch, Glen Nagle, Keith Novak,

  Betina Pavri, the RAD team, Scot Rafkin, Rich Rainen, Elizabeth Rampe, Mike Ravine,

  Melissa Rice, Matt Robinson, Mariek Schmidt, Katie Stack, Dawn Sumner, Lucy

  Thompson, Vandi Verma, Noah Warner, David Woerner, Aileen Yingst, and Allison

  Zastrow. With such a long list I am sure I am missing some names. To those I have missed,

  please accept my apologies and gratitude for your help.

  Thanks to Phil Stooke for generously sharing content of his own book in progress,

  particularly his frequently updated maps of the rover traverse. (The book, International Atlas of Mars Exploration Volume 2, complements this one.) Thanks to Mike Brown for helping me gain access to the Caltech library, which made remote research possible.

  Thanks to Tom Stein for supporting my use of the Analyst’s Notebook and taking some of

  my suggestions on improving its user interface. Thanks to Ralph Lorenz for his valuable

  advice on book writing: “Write chaptesimals, and eventually they will accrete into

  chapters.”

  xi

  xii Acknowledgments