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."
19 Kids and Counting built its reputation on preaching family values, but the mass-media platforms that made the family famous might also be their undoing.
On Thursday, news broke that Josh Duggar, the oldest son of the Duggar family's 19 children, had, as a teenager, allegedly molested five underage girls. Four of them, allegedly, were his sisters.
The information came to light because, in 2006—two years before 17 Kids and Counting first aired on TLC, and thus two years before the Duggars became reality-TV celebrities—the family recorded an appearance on TheOprah Winfrey Show. Before the taping, an anonymous source sent an email to Harpo warning the production company Josh’s alleged molestation. Harpo forwarded the email to authorities, triggering a police investigation (the Oprah appearance never aired). The news was reported this week by In Touch Weekly—after the magazine filed a Freedom of Information Act request to see the police report on the case—and then confirmed by the Duggars in a statement posted on Facebook.
New research confirms what they say about nice guys.
Smile at the customer. Bake cookies for your colleagues. Sing your subordinates’ praises. Share credit. Listen. Empathize. Don’t drive the last dollar out of a deal. Leave the last doughnut for someone else.
Sneer at the customer. Keep your colleagues on edge. Claim credit. Speak first. Put your feet on the table. Withhold approval. Instill fear. Interrupt. Ask for more. And by all means, take that last doughnut. You deserve it.
Follow one of those paths, the success literature tells us, and you’ll go far. Follow the other, and you’ll die powerless and broke. The only question is, which is which?
Of all the issues that preoccupy the modern mind—Nature or nurture? Is there life in outer space? Why can’t America field a decent soccer team?—it’s hard to think of one that has attracted so much water-cooler philosophizing yet so little scientific inquiry. Does it pay to be nice? Or is there an advantage to being a jerk?
In an interview, the U.S. president ties his legacy to a pact with Tehran, argues ISIS is not winning, warns Saudi Arabia not to pursue a nuclear-weapons program, and anguishes about Israel.
On Tuesday afternoon, as President Obama was bringing an occasionally contentious but often illuminating hour-long conversation about the Middle East to an end, I brought up a persistent worry. “A majority of American Jews want to support the Iran deal,” I said, “but a lot of people are anxiety-ridden about this, as am I.” Like many Jews—and also, by the way, many non-Jews—I believe that it is prudent to keep nuclear weapons out of the hands of anti-Semitic regimes. Obama, who earlier in the discussion had explicitly labeled the supreme leader of Iran, Ayatollah Ali Khamenei, an anti-Semite, responded with an argument I had not heard him make before.
“Look, 20 years from now, I’m still going to be around, God willing. If Iran has a nuclear weapon, it’s my name on this,” he said, referring to the apparently almost-finished nuclear agreement between Iran and a group of world powers led by the United States. “I think it’s fair to say that in addition to our profound national-security interests, I have a personal interest in locking this down.”
The Islamic State is no mere collection of psychopaths. It is a religious group with carefully considered beliefs, among them that it is a key agent of the coming apocalypse. Here’s what that means for its strategy—and for how to stop it.
What is the Islamic State?
Where did it come from, and what are its intentions? The simplicity of these questions can be deceiving, and few Western leaders seem to know the answers. In December, The New York Times published confidential comments by Major General Michael K. Nagata, the Special Operations commander for the United States in the Middle East, admitting that he had hardly begun figuring out the Islamic State’s appeal. “We have not defeated the idea,” he said. “We do not even understand the idea.” In the past year, President Obama has referred to the Islamic State, variously, as “not Islamic” and as al-Qaeda’s “jayvee team,” statements that reflected confusion about the group, and may have contributed to significant strategic errors.
In any case, people have probably heard the phrase in reference to something gone awry at work or in life. In either setting, when the shit does hit the fan, people will tend to look to the most competent person in the room to take over.
And too bad for that person. A new paper by a team of researchers from Duke University, University of Georgia, and University of Colorado looks at not only how extremely competent people are treated by their co-workers and peers, but how those people feel when, at crucial moments, everyone turns to them. They find that responsible employees are not terribly pleased about this dynamic either.
Why agriculture may someday take place in towers, not fields
A couple of Octobers ago, I found myself standing on a 5,000-acre cotton crop in the outskirts of Lubbock, Texas, shoulder-to-shoulder with a third-generation cotton farmer. He swept his arm across the flat, brown horizon of his field, which was at that moment being plowed by an industrial-sized picker—a toothy machine as tall as a house and operated by one man. The picker’s yields were being dropped into a giant pod to be delivered late that night to the local gin. And far beneath our feet, the Ogallala aquifer dwindled away at its frighteningly swift pace. When asked about this, the farmer spoke of reverse osmosis—the process of desalinating water—which he seemed to put his faith in, and which kept him unafraid of famine and permanent drought.
The former secretary of state jettisons sweeping rhetoric, and focuses on specific policies.
Hillary Clinton has been an official candidate for president for five weeks, and she still hasn’t done the thing most candidates do on day one: given a speech laying out her vision for America. Nor is she planning on doing so anytime soon. Politicoreports that Hillary’s “why I’m running for president,” speech, initially scheduled for May, has now been delayed until June, or even later.
There’s a reason for that: The speech is unlikely to be very good. Soaring rhetoric and grand themes have never been Hillary’s strengths. That’s one reason so many liberals found her so much less inspirational than Barack Obama in 2008. And it’s a problem with deep roots. In his biography, A Woman in Charge, Carl Bernstein describes Hillary, then in law school, struggling to articulate her generation’s perspective in an address to the League of Women Voters. “If she was speaking about a clearly defined subject,” Bernstein writes, “her thoughts would be well organized, finely articulated, and delivered in almost perfect outline form. But before the League audience, she again and again lapsed into sweeping abstractions.”
A scholar’s analysis of American culture presumes too much.
Last week, Gawkerinterviewed Robin DiAngelo, a professor of multicultural education at Westfield State University. She discussed aspects of her thinking on whiteness, which are set forth at length in her book, What Does it Mean to be White? I’ve ordered the book.
Meanwhile, her remarks on police brutality piqued my interest. Some of what Professor DiAngelo said is grounded in solid empirical evidence: blacks and Hispanics are disproportionately victimized by misbehaving police officers; there are neighborhoods where police help maintain racial and class boundaries. And if our culture, which she calls “the water we swim in,” contained fewer parts racism per million, I suspect that police brutality would be less common.
Science says lasting relationships come down to—you guessed it—kindness and generosity.
Every day in June, the most popular wedding month of the year, about 13,000 American couples will say “I do,” committing to a lifelong relationship that will be full of friendship, joy, and love that will carry them forward to their final days on this earth.
Except, of course, it doesn’t work out that way for most people. The majority of marriages fail, either ending in divorce and separation or devolving into bitterness and dysfunction. Of all the people who get married, only three in ten remain in healthy, happy marriages, as psychologist Ty Tashiro points out in his book The Science of Happily Ever After, which was published earlier this year.
Social scientists first started studying marriages by observing them in action in the 1970s in response to a crisis: Married couples were divorcing at unprecedented rates. Worried about the impact these divorces would have on the children of the broken marriages, psychologists decided to cast their scientific net on couples, bringing them into the lab to observe them and determine what the ingredients of a healthy, lasting relationship were. Was each unhappy family unhappy in its own way, as Tolstoy claimed, or did the miserable marriages all share something toxic in common?