Curiosity is a $2.5 billion effort and the culmination of a successful decade of Martian exploration for NASA after the loss of two probes in 1999. The size of a small SUV and weighing 2,000 pounds, Curiosity is five times as big as its predecessors Spirit and Opportunity, which landed on Mars in 2004. Because Curiosity is so much heavier, NASA’s old airbag landing system wouldn’t work. Engineers had to come up with a new system, dubbed a “sky crane,” in which Curiosity was lowered to Mars’s surface by a winch held up by rockets, which had deployed after an enormous parachute first slowed the rover down.
Curiosity’s size not only gives it a greater range than the previous rovers had but also allows it to carry a small, mobile laboratory called SAM (Sample Analysis at Mars). SAM consists of a small drill that can penetrate rocks, allowing a more detailed analysis than ChemCam, though of a more limited number of samples. The elaborate nature of Curiosity’s instruments in part obviates the need for something geologists have been lobbying for ever since the Viking landers first visited Mars in 1975: a sample-return mission that would bring rocks from Mars back to Earth. Such a mission is the next logical step after Curiosity, but NASA’s backing for it has been erratic. The agency’s unsteady support for exploration generally is a major theme of Wiens’s story.
Wiens has spent the bulk of his career at the Department of Energy’s Los Alamos laboratory. He tells of arriving there and finding file cabinets that “looked like they had a bad case of acne.” (They had been scarred by laser tests.) Before coming to work on ChemCam, Wiens devoted himself to the Genesis space probe, which was meant to bring samples of the solar wind back to Earth, and did so. However, its parachute failed to open, and the craft crashed into the Utah desert. This crash is the emotional nadir of Wiens’s story, even though he and his colleagues were able to recover some data from the downed probe. “This was a disaster,” he writes. “Something terrible had happened.” Unfortunately he is unable to rise above cliche at this crucial juncture to convey to the reader the full force of the sadness and frustration he no doubt felt.
He is a good guide through the process of building a space probe, however. Wiens talks about jerry-rigging part of Genesis with a cooking pot bought at a hardware store. When he had to test Genesis’s ability to withstand micrometeoroid impacts, an expensive NASA test facility in Houston was booked, so he took his detector to a local shooting range and shot it up with a rifle. The detector he used in ChemCam was designed “for use in grocery-store bar-code scanners.”
Without vitriol, Wiens contrasts his team’s willingness to improvise with the hidebound mentality of NASA’s bureaucracy. There was often, he writes, a “catch-22 that prevents many new concepts from coming to fruition: Without having flown before, new instruments are too risky to be selected for flight.” NASA’s response to budget crunches was frequently to eliminate contingency funds or backup plans. The result was that when something did go wrong, it ended up being even more costly to fix. At times, Wiens found ways around these limitations, as when he glued together parts that should have been “fastened properly with screws or nuts and bolts.”
The scientific instruments on Curiosity account for only a small part of the mission cost — $75 million (though this number later rose somewhat). Wiens tells several stories about the agency’s reaction to budget squeezes: “Most of the large missions I had known ended up in financial trouble immediately. NASA’s usual response was to remove instruments from the payload. These removals, or descopes, could sometimes cripple the mission’s scientific return while yielding only a very small cost savings.”
Wiens talks about how the agency frequently partners with foreign governments, not because this makes technical sense, but because NASA bureaucrats can exploit the entanglement with foreigners to protect their own funding from political meddling. Such joint efforts are made still more complicated by a byzantine system of export controls that in principle are meant to prevent sensitive technologies from spreading outside the United States but in practice are just a frustrating barrier to getting work done.
His inside narration of how things go wrong at NASA is the great strength of this book. It is rich with details of how both the ChemCam team in particular and the Curiosity rover in general overcame engineering challenges such as faulty lenses and awkward temperature distributions.
But the narrow focus on Wiens’s personal experience makes the book less useful than Rod Pyle’s “Destination Mars,” which is the best recent overview of Mars missions, or Oliver Morton’s “Mapping Mars,” which, because it gets away from particular missions as a framing device and talks about the planet itself, remains (though it is a decade old) perhaps the best single volume about the Red Planet.
Wiens ends his book shortly after Curiosity lands on Mars. This is a problem because, although he has taken us through ChemCam’s design and told us what it can do, by the close of the book, it has yet to do anything. It is able to analyze Martian rocks to find out if they were part of a riverbed or formed by a volcano, and to tell us something about the planet’s history. But these missions are unaccomplished when the book ends.
The premature end of Wiens’s story is unfortunate because he is such a sympathetic narrator. But it may be symptomatic of how he somewhat buys into the NASA mentality in which missions are justified as ends in themselves, rather than on the basis of the scientific discoveries made. To persuade the public and Congress that a costly sample-return mission is worthwhile, Wiens and his colleagues will have to do a better job of tying together their engineering marvels — the precision navigation and elaborate sky cranes — with the science that results.
is a Bernard Schwartz fellow at the New America Foundation and the author of a forthoming e-book, “The Pioneer Detectives: Did a Faraway Space Probe Prove Einstein and Newton Wrong?”