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."
Demonizing processed food may be dooming many to obesity and disease. Could embracing the drive-thru make us all healthier?
Late last year, in a small health-food eatery called Cafe Sprouts in Oberlin, Ohio, I had what may well have been the most wholesome beverage of my life. The friendly server patiently guided me to an apple-blueberry-kale-carrot smoothie-juice combination, which she spent the next several minutes preparing, mostly by shepherding farm-fresh produce into machinery. The result was tasty, but at 300 calories (by my rough calculation) in a 16-ounce cup, it was more than my diet could regularly absorb without consequences, nor was I about to make a habit of $9 shakes, healthy or not.
Inspired by the experience nonetheless, I tried again two months later at L.A.’s Real Food Daily, a popular vegan restaurant near Hollywood. I was initially wary of a low-calorie juice made almost entirely from green vegetables, but the server assured me it was a popular treat. I like to brag that I can eat anything, and I scarf down all sorts of raw vegetables like candy, but I could stomach only about a third of this oddly foamy, bitter concoction. It smelled like lawn clippings and tasted like liquid celery. It goes for $7.95, and I waited 10 minutes for it.
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.
Some Republican candidates are promoting a policy change that would hurt workers by disguising it with a pleasant-sounding phrase.
Americans like their Social Security benefits quite a bit: They oppose cuts to them by a margin of two to one. Even Millennials, who won’t be seeing benefits anytime soon, feel protective of Social Security, according to a poll from the Pew Research Center.
One way to effectively cut Social Security benefits is to raise the age at which they kick in. And yet, when asked specifically about raising the retirement age, Americans are mixed.
Perhaps confusion arises because “raising the age of retirement” sounds like a nice jobs program for older Americans, or an end to forced retirement. I sympathize with that position: Anyone who wants to retire later and work into old age should have a job. But that’s not what raising the retirement age would entail—the fact is, raising the Social Security retirement age represents a reduction in benefits: Because the monthly payments a person receives grow bigger the later in life he or she retires, raising the age cutoff reduces the total amount of money paid out.
In continuing to tinker with the universe she built eight years after it ended, J.K. Rowling might be falling into the same trap as Star Wars’s George Lucas.
September 1st, 2015 marked a curious footnote in Harry Potter marginalia: According to the series’s elaborate timeline, rarely referenced in the books themselves, it was the day James S. Potter, Harry’s eldest son, started school at Hogwarts. It’s not an event directly written about in the books, nor one of particular importance, but their creator, J.K. Rowling, dutifully took to Twitter to announce what amounts to footnote details: that James was sorted into House Gryffindor, just like his father, to the disappointment of Teddy Lupin, Harry’s godson, apparently a Hufflepuff.
It’s not earth-shattering information that Harry’s kid would end up in the same house his father was in, and the Harry Potter series’s insistence on sorting all of its characters into four broad personality quadrants largely based on their family names has always struggled to stand up to scrutiny. Still, Rowling’s tweet prompted much garment-rending among the books’ devoted fans. Can a tweet really amount to a piece of canonical information for a book? There isn’t much harm in Rowling providing these little embellishments years after her books were published, but even idle tinkering can be a dangerous path to take, with the obvious example being the insistent tweaks wrought by George Lucas on his Star Wars series.
Heather Armstrong’s Dooce once drew millions of readers. Her blog’s semi-retirement speaks to the challenges of earning money as an individual blogger today.
The success story of Dooce.com was once blogger lore, told and re-told in playgroups and Meetups—anywhere hyper-verbal people with Wordpress accounts gathered. “It happened for that Dooce lady,” they would say. “It could happen for your blog, too.”
Dooce has its origin in the late 1990s, when a young lapsed Mormon named Heather Armstrong taught herself HTML code and moved to Los Angeles. She got a job in web design and began blogging about her life on her personal site, Dooce.com.
The site’s name evolved out of her friends’ AOL Instant-Messenger slang for dude, or its more incredulous cousin, "doooood!” About a year later, Armstrong was fired for writing about her co-workers on the site—an experience that, for a good portion of the ‘aughts, came known as “getting dooced.” She eloped with her now ex-husband, Jon, moved to Salt Lake City, and eventually started blogging full time again.
Encouraging a focus on white identity is a dangerous approach for a country in which white supremacy has been a toxic force.
Donald Trump and the disaffected white people who make up his base of support have got me thinking about race in America. “Trump presents a choice for the Republican Party about which path to follow––” Ben Domenech writes in an insightful piece at The Federalist, “a path toward a coalition that is broad, classically liberal, and consistent with the party’s history, or a path toward a coalition that is reduced to the narrow interests of identity politics for white people.”
When I was growing up in Republican Orange County during the Reagan and Bush Administrations, lots of white parents sat their kids in front of The Cosby Show, explained that black people are just like white people, and inveighed against judging anyone by the color of their skin rather than the content of their character. The approach didn’t convey the full reality of race as minorities experience it. But it represented a significant generational improvement in race relations.
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.
Burning Man is underway in the Nevada desert, the migrant crisis grew in both scale and impact, new Star Wars toys went on sale worldwide, China marked the 70thanniversary of the end of World War II, Alaska’s Mt. McKinley was renamed Denali, and much more.
Burning Man is underway in the Nevada desert, the migrant crisis grew in both scale and impact, new Star Wars toys went on sale worldwide, China marked the 70th anniversary of the end of World War II, Alaska’s Mt. McKinley was renamed Denali, a Kentucky county clerk was jailed for contempt of court while refusing to issue same-sex marriage licenses, and much more.
After a lackluster summer, the famous neurosurgeon is finally surging—but his reliance on the conservative grassroots might be a burden as much as a boon.
The Ben Carson surge that everyone was waiting for is finally here.
The conservative neurosurgeon has been a source of fascination for both the Republican grassroots and the media ever since he critiqued President Obama, who was seated only a few feet away, at the National Prayer Breakfast in 2013. He’s been a steady, if middling, presence in GOP primary polls for most of the year—always earning at least 5 percent, but rarely more than 10. Yet over the last two weeks, Carson has secured a second-place spot after Donald Trump, both nationally and in the crucial opening battleground of Iowa, where he is a favorite of the state’s sizable evangelical community. A Monmouth University poll released this week even showed him tied with Trump for the lead in Iowa, at 23 percent.