by The Design
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
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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