The conventional wisdom of space exploration suggests that robotic probes are both more scientifically efficient and cost effective. Not so, argues a professor of planetary science.
Astronaut Edwin E. Aldrin Jr., lunar module pilot, poses beside the deployed flag of the United States during the Apollo XI moon landing July 20, 1969. [Reuters]
When the Space Shuttle Atlantis rolled to a stop in July 2011, NASA bid farewell to the nation's symbol of manned spaceflight. The Obama administration has scrapped NASA's plan to return humans to the Moon by 2020, which was behind schedule because of technical and budgetary problems. As financial constraints threaten the possibility of future ventures into outer space, many in the astronomical community are advocating for the increased use of unmanned robotic
space, arguing that they will serve as more efficient explorers of planetary surfaces
than astronauts. The next giant leap, then, will be taken with robotic feet.
At the core of Crawford's argument is that human beings are much better at performing the type of geological fieldwork that makes planetary exploration scientifically valuable: they're faster and significantly more versatile than even the most advanced autonomous probes. "People who argue for robotic exploration argue for more artificial intelligence, the capacity for robots to make more complex decisions that somehow leads to increased efficiency," explains Crawford. "But one of the things that make them cheap is miniaturization.You can make robots more intelligent and efficient to a certain point, but they wont get smaller and therefore cheaper." With miniaturization, he explains, comes a depletion in the number of scientific instruments a probe can carry, the number of samples it can collect, and its ability to cover more ground. " [Mars rovers] Spirit and Opportunity are fantastic things on Mars, but the fact that they've traveled as far in eight years as the Apollo astronauts traveled in three days speaks volumes." At a certain point, the costs of developing 'smarter' (but not better equipped) autonomous rovers will exceed the meager gains in scientific collection and outstrip existing scientific budgets.
The advantages of human over robot explorers are recognized in the planetary sciences community: a 2005 report by the Commission on the Scientific Case for Human Space Exploration noted that "the expert evidence we have heard strongly suggests that the use of autonomous robots alone will very significantly limit what can be learned about our nearest potentially habitable planet." Steve Squyres, the Principal Investigator for the Mars Exploration Rovers Spirit and Opportunity, conceded in his book Roving Mars that "[t]he unfortunate truth is that most things our rovers can do in a perfect sol [a martian day] a human explorer could do in less than a minute." But Crawford also expresses concerns over the capacity of robots for "making serendipitous discoveries."
"We may be able to make robots smarter, but they'll never get tot he point where they can make on the spot decisions in the field, where they can recognize things for being important even if you don't expect them or anticipate them," argues Crawford. "You can't necessarily program a robot to recognize things out of the blue."
The other downside of a shift towards robotic exploration is the decline of samples, the real meat of the planetary sciences. Robotic expeditions have always been one-way trips: the probes go, land, take readings, and don't come back. But the collection and prolonged study of planetary samples are real drivers of scientific knowledge, which Crawford measures in terms of published scientific literature:
Several things are immediately apparent from Figure 2. Most obvious is the sheer
volume of Apollo's scientific legacy compared to the other missions illustrated. This
alone goes a long way to vindicate the points made above about human versus robotic
efficiency. The second point to note is that the next most productive set of missions
are the lunar sample return missions Lunas 16, 20 and 24, which highlights the
importance of sample return. Indeed, a large part of the reason why Apollo has
resulted in many more publications than the Luna missions is due to the much larger
quantity and diversity of the returned samples which, as we have seen, will always be
greater in the context of human missions. The third point to note is that, despite being
based on data obtained and samples collected over 40 years ago, and unlike the Luna,
Lunokhod, or Surveyor publications, which have clearly levelled off, the Apollo
publication rate is still rising. Indeed, it is actually rising as fast as, or faster than, the
publications rate derived from the Mars Exploration Rovers, despite the fact that data
derived from the latter are much more recent. No matter how far one extrapolates into
the future, it is clear that the volume of scientific activity generated by the MERs, or
other robotic exploration missions, will never approach that due to Apollo.
"We're still benefiting from the scientific legacy of those few soil samples brought by the Apollo mission, but we can only do this because we went to the Moon, got these samples, and came back," says Crawford. "If we sent a rover to Mars along with a return vehicle, that would enormously increase its scientific impact, but that's hasn't been implemented yet because its still incredibly expensive. If a mission goes to Mars, lands in one place, bring back half a kilogram of Mars rocks, it will be immensely valuable, but compared to Apollo, which not only visited six sites (and many hundred of sites with the help of the lunar rover) but came back with 382 kilograms of lunar material, it sort of pales in comparison."
While robotic probes find a permanent home on a planetary surface, sending manned expeditions inherently means planning for a return trip. Would a manned trip to Mars, replete with a sample-laden return vehicle, yield a similar explosion in scientific literature? Crawford thinks so. "A Martian expedition would be 5 or 10 times more expensive than Apollo in real terms, but not so much more expensive that it would negate the added benefit of being able to collect samples. They'll bring back a much larger quantity and diversity of samples than a robotic mission, and this is especially important with regards to Mars: there are reasons for wanting more lunar samples, but Mars is a much bigger and much more geologically diverse planet, with a much more complicated geology so much more inconceivably complicated history than the Moon, we won't get a full sense of its history or evolution just by scraping around on the surface with these smalls robot probes."
The scientific impact of these moon rocks is compelling: our whole
chronology of the solar system is built on the radiometric dating of the
Apollo samples. "The top scientific benefit is that it's been possible
to date areas of the lunar surface. We have this curve that plots crater density versus age, which we can use to get an estimated age of
virtually anywhere else in the Solar System," explains Crawford.
"The last major eruption of Olympus Mons [on Mars] was 400 million years
ago, and the only way we have this measurement is because of Apollo
So why, then, are scientists resigned to sending probes and rovers to the corners of the galaxy? Scientists, argues Crawford, tend to look at the enormous costs for Apollo, which nobody will ever be able to afford again, as an artificial baseline for gradual streamlining of space exploration. This is the wrong approach to take "There's lots of collective amnesia as to how efficient Apollo really was, which is really the only example of exploring the surface of another planet," explains Crawford. "An enormous amount was achieved in a very short total contact time with the lunar surface."
Planners feel the microscopic formations in Mars meteorite ALH84001, found in Antarctica, and the highly diverse samples of rocks believed to have been strewn about by ancient rivers seen at the Mars Pathfinder landing site, provide a strong motive for sending human exobiologists and geologists to the Red Planet. [Pat Rawlings/NASA]
But Crawford recognizes that, despite its benefits for scientific research, manned missions are subject to domestic forces and rarely undertaken for the sake of science alone. The United States was willing to shoulder the enormous costs of the Apollo mission because of the geopolitical and economic interests (namely, besting the Soviet Union), an argument advanced most recently by science communicator Neil DeGrasse Tyson.
"Science was the beneficiary of a human spaceflight mission that was undertaken for geopolitical purposes," explains Crawford. "The total costs is large, but the best way for scientists to look at it is not 'this is a science function.' They need to look at Apollo as the confluence of geopolitical, industrial, and social factors. You need all of these things to spend the money necessary."
Crawford's theory, then, is not necessarily targeted towards the general public: he recognizes the difficulty of justifying an expensive manned mission with no immediate economic benefit (although he notes notes that the 1987 NASA procurement of $8.6 billion generated a turnover of $17.8 billion and created 209,000 private sector jobs, according to an article in Nature), especially in the throes of an global economic downturn. His main argument, then is those scientists consigning themselves to a future of interstellar probes are shooting themselves in the foot. Ventures like the James Webb Space Telescope may hit the ceiling for government expenditures on purely scientific ventures, but researchers and scientists can -- and should -- try to make the case for manned spaceflight in other contexts, if only for the sake of maximizing the scientific gains made from planetary exploration.
"Humans bring a net benefit to space exploration that, in my opinion, outweighs the costs," says Crawford. "But people need to realize that the overall case for manned spaceflight is multifaceted, a totality woven out of these different strands, of which science is one. Industry, innovation, inspirational value -- all of these factors must be addressed before manned spaceflight can return."
In an interview, the U.S. secretary of state calls the Iran nuclear pact “as pro-Israel as it gets.” He also casts doubt on the charge that the Iranian regime seeks the destruction of the Jewish state.
When I met with Secretary of State John Kerry in his office this past Friday, it was apparent that he was in an exceedingly feisty mood, and it’s not easy to display feistiness when you’re trapped, as he was, in a recliner. Kerry, who broke his leg two months ago, will be rid of his crutches soon, which for him is not soon enough, because he’d prefer to do battle in Congress for the Iran nuclear agreement—quite obviously the crowning achievement, in his mind, of his long and distinguished career in public life—with two good legs.
Congress is the target of Kerry’s feistiness, as is his close friend and staunch adversary, the Israeli prime minister, Benjamin Netanyahu, who is leading the charge against congressional ratification of the deal. In the course of a lengthy and freewheeling interview—which you will find published in full, below—Kerry warned that if Congress rejects the Iran deal, it will confirm the anti-U.S. suspicions harbored by the Iranian supreme leader, Ayatollah Ali Khamenei, and eliminate any chance of a peaceful solution to the nuclear conundrum:
Why the obsession with our kids’ happiness may be dooming them to unhappy adulthoods. A therapist and mother reports.
If there’s one thing I learned in graduate school, it’s that the poet Philip Larkin was right. (“They fuck you up, your mum and dad, / They may not mean to, but they do.”) At the time, I was a new mom with an infant son, and I’d decided to go back to school for a degree in clinical psychology. With baby on the brain and term papers to write, I couldn’t ignore the barrage of research showing how easy it is to screw up your kids. Of course, everyone knows that growing up with “Mommy Dearest” produces a very different child from one raised by, say, a loving PTA president who has milk and homemade cookies waiting after school. But in that space between Joan Crawford and June Cleaver, where most of us fall, it seemed like a lot could go wrong in the kid-raising department.
What would the American culture wars look like if they were less about “values” and more about Jesus?
Evangelical Christianity has long had a stranglehold on how Americans imagine public faith. Vague invocations of “religion”—whether it’s “religion vs. science” or “religious freedom”—usually really mean “conservative, Protestant, evangelical Christianity,” and this assumption inevitably frames debates about American belief. For the other three-quarters of the population—Catholics, Jews, other Protestants, Muslims, Hindus, secular Americans, Buddhists, Wiccans, etc.—this can be infuriating. For some evangelicals, it’s a sign of success, a linguistic triumph of the culture wars.
But not for Russell Moore. In 2013, the 43-year-old theologian became the head of the Ethics and Religious Liberty Commission, the political nerve center of the Southern Baptist Convention. His predecessor, Richard Land, prayed with George W. Bush, played hardball with Democrats, and helped make evangelicals a quintessentially Republican voting bloc.
The winners of the 27th annual National Geographic Traveler Photo Contest have just been announced.
The winners of the 27th annual National Geographic Traveler Photo Contest have just been announced. Winning first prize, Anuar Patjane Floriuk of Tehuacán, Mexico, will receive an eight-day photo expedition for two to Costa Rica and the Panama Canal for a photograph of divers swimming near a humpback whale off the western coast of Mexico. Here, National Geographic has shared all of this year’s winners, gathered from four categories: Travel Portraits, Outdoor Scenes, Sense of Place, and Spontaneous Moments. Captions by the photographers.
Many psychiatrists believe that a new approach to diagnosing and treating depression—linking individual symptoms to their underlying mechanisms—is needed for research to move forward.
In his Aphorisms, Hippocrates defined melancholia, an early understanding of depression, as a state of “fears and despondencies, if they last a long time.” It was caused, he believed, by an excess of bile in the body (the word “melancholia” is ancient Greek for “black bile”).
Ever since then, doctors have struggled to create a more precise and accurate definition of the illness that still isn’t well understood. In the 1920s, the German psychiatrist Kurt Schneider argued that depression could be divided into two separate conditions, each requiring a different form of treatment: depression that resulted from changes in mood, which he called “endogenous depression,” and depression resulting from reactions to outside events, or “reactive depression.” His theory was challenged in 1926, when the British psychologist Edward Mapother argued in the British Medical Journal that there was no evidence for two distinct types of depression, and that the apparent differences between depression patients were just differences in the severity of the condition.
The jobs that are least vulnerable to automation tend to be held by women.
Many economists and technologists believe the world is on the brink of a new industrial revolution, in which advances in the field of artificial intelligence will obsolete human labor at an unforgiving pace. Two Oxford researchers recently analyzed the skills required for more than 700 different occupations to determine how many of them would be susceptible to automation in the near future, and the news was not good: They concluded that machines are likely to take over 47 percent of today’s jobs within a few decades.
This is a dire prediction, but one whose consequences will not fall upon society evenly. A close look at the data reveals a surprising pattern: The jobs performed primarily by women are relatively safe, while those typically performed by men are at risk.
Blame Prohibitionists, German immigrants, and factory workers who just wanted to drink during their lunch break.
Today’s discerning beer drinkers might be convinced that America’s watery, bland lagers are a recent corporate invention. But the existence of American beers that are, as one industry executive once put it, “less challenging,” has a much longer history. In fact, Thomas Jefferson, himself an accomplished homebrewer, complained that some of his country’s beers were “meagre and often vapid” nearly 200 years ago.
Jefferson never lived to see the worst of it. Starting in about the mid-1800s, American beer has been defined by its dullness. Why? The answer lies in a combination of religious objections to alcohol, hordes of German immigrants, and a bunch of miners who just wanted to drink during their lunch break, says Ranjit Dighe, a professor of economics at the State University of New York at Oswego.
Paul faced danger, Ani and Ray faced each other, and Frank faced some career decisions.
This is what happens when you devote two-thirds of a season to scene after scene after scene of Frank and Jordan’s Baby Problems, and Frank Shaking Guys Down, and Look How Fucked Up Ray and Ani Are, and Melancholy Singer in the Dive Bar Yet Again—and then you suddenly realize that with only a couple episodes left you haven’t offered even a rudimentary outline of the central plot.
Exceptional nonfiction stories from 2014 that are still worth encountering today
Each year, I keep a running list of exceptional nonfiction that I encounter as I publish The Best ofJournalism, an email newsletter that I send out once or twice a week. This is my annual attempt to bring some of those stories to a wider audience. I could not read or note every worthy article that was published last calendar year and I haven't included any paywalled articles or anything published at The Atlantic. But everything that follows is worthy of wider attention and engagement.
What if Joe Biden is going to run for the Democratic nomination after all?
Most Democrats seem ready for Hillary Clinton—or at least appear content with her candidacy. But what about the ones who who were bidin’ for Biden? There are new signs the vice president might consider running for president after all.
Biden has given little indication he was exploring a run: There’s no super PAC, no cultivation of a network of fundraisers or grassroots organizers, few visits to early-primary states. While his boss hasn’t endorsed Clinton—and says he won’t endorse in the primary—many members of the Obama administration have gone to work for Clinton, including some close to Biden.
But Biden also hasn’t given any clear indication that he isn’t running, and a column by Maureen Dowd in Saturday’s New York Times has set off new speculation. One reason Biden didn’t get into the race was that his son Beau was dying of cancer, and the vice president was focused on being with his son. But before he died in May, Dowd reported, Beau Biden tried to get his father to promise to run. Now Joe Biden is considering the idea.