Review: recalling Sojourner

Monday, December 22, 2003

Sojourner: An Insider’s View of the Mars Pathfinder Mission
By Andrew Mishkin
Berkley Books, 2004
Hardcover, 334pp., illus.
ISBN 0-425-19199-0
US$21.95/C$33.00

Next month NASA’s twin Mars Exploration Rovers, dubbed Spirit and Opportunity, will, if all goes well, spend several weeks moving around their widely-separated landing sites, collecting data on the composition of the rocks and soils there. A successful mission could help scientists understand the early history of the Red Planet, including how much water it had and where that water went, and could generate momentum for future robotic and even human exploration of the planet. The Mars Exploration Rovers will also draw comparisons with another, although very different, rover mission: the Sojourner rover on Mars Pathfinder.

In Sojourner: An Insider’s View of the Mars Pathfinder Mission, JPL engineer Andrew Mishkin provides a behind-the-scenes look at the history of that famous rover. Much has already been written about the rover and the uphill fight to get it built and included on the Mars Pathfinder mission, but as the title suggests, Mishkin provides a new perspective: he was involved with the Microrover Flight Experiment (as it was originally, officially called) from the beginning, eventually leading the rover operations team. This gives the book a fresh, detailed insight into how Sojourner successfully evolved from concept to reality.

While the book is about the development of Sojourner, it starts with the prehistory of the project, dating back to early rover work at the Jet Propulsion Laboratory in the 1980s, in one case using a rover developed in the 1960s as part of the Surveyor lunar lander program but never flown. Much of this early work was looking at larger rovers that could be used on a proposed Martian sample return mission, but engineers also examined much smaller “microrovers” that could be integrated into lander missions. When the sample return mission plans fell apart in the early 1990s and an alterative concept, the Mars Environmental Survey (MESUR), a network of landers, gained support, it provided an opening for flying a microrover to Mars.

Those plans took shape as NASA endorsed plans for a mission to send a MESUR prototype, MESUR Pathfinder, to Mars, a mission that would include a microrover. (MESUR Pathfinder became Mars Pathfinder when NASA decided not to pursue the MESUR concept, which would have required up to 20 identical landers.) The book follows the development of the rover, including the technical challenges involved with building an ambitious spacecraft on a limited schedule and a $25-million budget, as well as internal politics within the project, and with the overall Mars Pathfinder project (which reluctantly accepted Sojourner, and at point looked at dropping the rover in favor of a smaller, tethered rover.) While the development of Sojourner is the heart of the book, the actual Pathfinder mission itself, from launch to the end of the mission, is also included as soon from the point of view of the Sojourner team, with a focus on the technical accomplishments versus the scientific results of the mission.

Sojourner goes into far greater detail about the development of the rover than any previous book, thanks to Mishkin’s position as a participant in the project. As with any book about a major event written by one of the participants, readers should be aware of the possibility that history may be rewritten in such a way to enhance the standing of the author and/or disparage other people or organizations. While only those select few who participated in the project know for certain the course of events, there are no obvious signs that Mishkin is rewriting history. He has few, if any, axes to grind in the book, and he has gone to considerable lengths to maintain some degree of accuracy: he notes in the preface that in those sections of the book where conversations are recreated, he has had at least one party of the original conversation review the text to ensure that the gist, if not the actual words, is correct.

If there is one down side to the book, it is that, at times, it can get too deep into technical details about the development and operation of Sojourner for the casual reader. There is occasionally an alphabet soup of acronyms, although Mishkin helpfully includes a glossary of acronyms in the back of the book. Overall, Sojourner is not just the most detailed description to date of the Sojourner rover project, but one of the better histories in recent years of any spaceflight project. As the Mars Exploration Rovers set down on the surface of the Red Planet in the next few weeks, Sojourner reminds us that they are following a trail of exploration blazed by another rover and a team of dedicated engineers.

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