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."
Forget the Common Core, Finland’s youngsters are in charge of determining what happens in the classroom.
“The changes to kindergarten make me sick,” a veteran teacher in Arkansas recently admitted to me. “Think about what you did in first grade—that’s what my 5-year-old babies are expected to do.”
The difference between first grade and kindergarten may not seem like much, but what I remember about my first-grade experience in the mid-90s doesn’t match the kindergarten she described in her email: three and a half hours of daily literacy instruction, an hour and a half of daily math instruction, 20 minutes of daily “physical activity time” (officially banned from being called “recess”) and two 56-question standardized tests in literacy and math—on the fourth week of school.
That American friend—who teaches 20 students without an aide—has fought to integrate 30 minutes of “station time” into the literacy block, which includes “blocks, science, magnetic letters, play dough with letter stamps to practice words, books, and storytelling.” But the most controversial area of her classroom isn’t the blocks nor the stamps: Rather, it’s the “house station with dolls and toy food”—items her district tried to remove last year. The implication was clear: There’s no time for play in kindergarten anymore.
Meaning comes from the pursuit of more complex things than happiness
"It is the very pursuit of happiness that thwarts happiness."
In September 1942, Viktor Frankl, a prominent Jewish psychiatrist and neurologist in Vienna, was arrested and transported to a Nazi concentration camp with his wife and parents. Three years later, when his camp was liberated, most of his family, including his pregnant wife, had perished -- but he, prisoner number 119104, had lived. In his bestselling 1946 book, Man's Search for Meaning, which he wrote in nine days about his experiences in the camps, Frankl concluded that the difference between those who had lived and those who had died came down to one thing: Meaning, an insight he came to early in life. When he was a high school student, one of his science teachers declared to the class, "Life is nothing more than a combustion process, a process of oxidation." Frankl jumped out of his chair and responded, "Sir, if this is so, then what can be the meaning of life?"
Even in big cities like Tokyo, small children take the subway and run errands by themselves. The reason has a lot to do with group dynamics.
It’s a common sight on Japanese mass transit: Children troop through train cars, singly or in small groups, looking for seats.
They wear knee socks, polished patent-leather shoes, and plaid jumpers, with wide-brimmed hats fastened under the chin and train passes pinned to their backpacks. The kids are as young as 6 or 7, on their way to and from school, and there is nary a guardian in sight.
A popular television show called Hajimete no Otsukai, or My First Errand, features children as young as two or three being sent out to do a task for their family. As they tentatively make their way to the greengrocer or bakery, their progress is secretly filmed by a camera crew. The show has been running for more than 25 years.
A new study finds that people today who eat and exercise the same amount as people 20 years ago are still fatter.
There’s a meme aimed at Millennial catharsis called “Old Economy Steve.” It’s a series of pictures of a late-70s teenager, who presumably is now a middle-aged man, that mocks some of the messages Millennials say they hear from older generations—and shows why they’re deeply janky. Old Economy Steve graduates and gets a job right away. Old Economy Steve “worked his way through college” because tuition was $400. And so forth.
We can now add another one to that list: Old Economy Steve ate at McDonald’s almost every day, and he still somehow had a 32-inch waist.
A study published recently in the journal Obesity Research & Clinical Practice found that it’s harder for adults today to maintain the same weight as those 20 to 30 years ago did, even at the same levels of food intake and exercise.
What happens when a father, alarmed by his 13-year-old daughter's nightly workload, tries to do her homework for a week
Memorization, not rationalization. That is the advice of my 13-year-old daughter, Esmee, as I struggle to make sense of a paragraph of notes for an upcoming Earth Science test on minerals. “Minerals have crystal systems which are defined by the # of axis and the length of the axis that intersect the crystal faces.” That’s how the notes start, and they only get murkier after that. When I ask Esmee what this actually means, she gives me her homework credo.
Esmee is in the eighth grade at the NYC Lab Middle School for Collaborative Studies, a selective public school in the Chelsea neighborhood of Manhattan. My wife and I have noticed since she started there in February of last year that she has a lot of homework. We moved from Pacific Palisades, California, where Esmee also had a great deal of homework at Paul Revere Charter Middle School in Brentwood. I have found, at both schools, that whenever I bring up the homework issue with teachers or administrators, their response is that they are required by the state to cover a certain amount of material. There are standardized tests, and everyone—students, teachers, schools—is being evaluated on those tests. I’m not interested in the debates over teaching to the test or No Child Left Behind. What I am interested in is what my daughter is doing during those nightly hours between 8 o’clock and midnight, when she finally gets to bed. During the school week, she averages three to four hours of homework a night and six and a half hours of sleep.
For some parents, the deadline for a kid's financial independence has gotten an extension.
My 22-year-old daughter, Emma, waved goodbye to her college campus last spring and walked into a job this fall. Given the still-tepid state of the economy and all the stories—in the news and from friends—about recent graduates who can’t find work, you might well imagine that my husband and I are thrilled. And we are. Sort of.
Emma’s job is a good one, and she is lucky to have it. She is an editorial assistant at a well-respected magazine. But it is the kind of job that countless millennials are landing these days: part-time, low paying, with no benefits.
So, after we spentnearly a quarter of a million dollars on her college education, one thing has become clear: Our investment in our daughter’s future is far from over.
In the name of emotional well-being, college students are increasingly demanding protection from words and ideas they don’t like. Here’s why that’s disastrous for education—and mental health.
Something strange is happening at America’s colleges and universities. A movement is arising, undirected and driven largely by students, to scrub campuses clean of words, ideas, and subjects that might cause discomfort or give offense. Last December, Jeannie Suk wrote in an online article for The New Yorker about law students asking her fellow professors at Harvard not to teach rape law—or, in one case, even use the word violate (as in “that violates the law”) lest it cause students distress. In February, Laura Kipnis, a professor at Northwestern University, wrote an essay in The Chronicle of Higher Education describing a new campus politics of sexual paranoia—and was then subjected to a long investigation after students who were offended by the article and by a tweet she’d sent filed Title IX complaints against her. In June, a professor protecting himself with a pseudonym wrote an essay for Vox describing how gingerly he now has to teach. “I’m a Liberal Professor, and My Liberal Students Terrify Me,” the headline said. A number of popular comedians, including Chris Rock, have stopped performing on college campuses (see Caitlin Flanagan’s article in this month’s issue). Jerry Seinfeld and Bill Maher have publicly condemned the oversensitivity of college students, saying too many of them can’t take a joke.
Will Joe Biden get in? Will Rand Paul get out? Can Ben Carson and Bernie Sanders keep tallying huge fundraising reports?
Political reporters are like sharks: No one likes them, you don’t want to see them at the beach, and once they smell blood in the water, they start circling. Hence two big stories this week: the continuing Joe Biden campaign watch, and the mounting Rand Paul death watch.
Every day that Hillary Clinton continues to struggle to put her email scandal behind her and change the subject, the pitched speculation about a Joe Biden run for president seems to increase. Several times a week, there seem to be new reports about Biden edging toward a run. (How near can he get? Does his proximity to a run keep increasing, asymptotically?) This week, CNN said it would hold a chair for the vice president to compete in the first Democrat debate until as late as the day of the debate, October 13. No dice: On Thursday, CNN itself reported that Biden won’t decide before the debate, but in the second half of October. These are only the latest revisions to a timeline that keeps moving back.
Perfect has been the way to be for several generations of women. I don’t remember my grandmothers suffering from this syndrome: women who raised families during the Depression, who baked and gardened and read well; who were fundamentally happy, and felt no pressure to look like stick figures. But those Mad Men years took their toll.
Racing in from a long day at the office, an evening of cooking and homework ahead, my first instinct is to go to the fridge or the cupboard and pop a cork. It soothes the transition from day to night. Chopping, dicing, sipping wine: It’s a common modern ritual.
For years it was me at the cutting board, a glass of chilled white at my side. And for years this habit was harmless—or it seemed that way. My house wine was Santa Margherita, a pale straw-blond Italian pinot grigio. There was always a bottle in my fridge, and I’d often pour a second glass before dinner, with seeming impunity.