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."
President-elect Donald Trump has committed a sharp breach of protocol—one that underscores just how weird some important protocols are.
Updated on December 2 at 7:49 p.m.
It’s hardly remembered now, having been overshadowed a few months later on September 11, but the George W. Bush administration’s first foreign-policy crisis came in the South China Sea. On April 1, 2001, a U.S. Navy surveillance plane collided with a Chinese jet near Hainan Island. The pilot of the Chinese jet was killed, and the American plane was forced to land and its crew was held hostage for 11 days, until a diplomatic agreement was worked out. Sino-American relations remained tense for some time.
Unlike Bush, Donald Trump didn’t need to wait to be inaugurated to set off a crisis in the relationship. He managed that on Friday, with a phone call to the president of Taiwan, Tsai Ing-wen. It’s a sharp breach with protocol, but it’s also just the sort that underscores how weird and incomprehensible some important protocols are.
A professor of cognitive science argues that the world is nothing like the one we experience through our senses.
As we go about our daily lives, we tend to assume that our perceptions—sights, sounds, textures, tastes—are an accurate portrayal of the real world. Sure, when we stop and think about it—or when we find ourselves fooled by a perceptual illusion—we realize with a jolt that what we perceive is never the world directly, but rather our brain’s best guess at what that world is like, a kind of internal simulation of an external reality. Still, we bank on the fact that our simulation is a reasonably decent one. If it wasn’t, wouldn’t evolution have weeded us out by now? The true reality might be forever beyond our reach, but surely our senses give us at least an inkling of what it’s really like.
A single dose of magic mushrooms can make people with severe anxiety and depression better for months, according to a landmark pair of new studies.
The doom hung like an anvil over her head. In 2012, a few years after Carol Vincent was diagnosed with non-Hodgkin lymphoma, she was waiting to see whether her cancer would progress enough to require chemotherapy or radiation. The disease had already done a number on her, inflating lymph nodes on her chin, collar bones, and groin. She battled her symptoms while running her own marketing business. To top it all off, she was going through menopause.
“Life is just pointless stress, and then you die,” she thought. “All I’m doing is sitting here waiting for all this shit to happen.”
When one day at an intersection she mulled whether it would be so bad to get hit by a car, she realized her mental health was almost as depleted as her physical state.
For nearly three decades, Fidel Castro devoted vast amounts of Cuba’s limited resources to the project of exporting his revolution to Africa, even as it stuttered at home. As leader of Cuba, Castro advocated a radical departure from the prevailing post-war liberal internationalism, premised more on the ideas of Frantz Fanon than those of Adam Smith. Decolonization seemed to offer a prime laboratory for that vision. Cuba volunteered doctors, nurses, military advisers, and troops to support what Castro and Che Guevara saw as progressive regimes—“sister countr[ies],” in Havana’s terminology—in Algeria, Eastern Congo-Kinshasa (today’s Democratic Republic of Congo), Congo-Brazzaville, Guinea-Bissau, and, later, Ethiopia.
A few weeks ago, I was trying to call Cuba. I got an error message—which, okay, international telephone codes are long and my fingers are clumsy—but the phone oddly started dialing again before I could hang up. A voice answered. It had a British accent and it was reading: “...the moon was shining brightly. The Martians had taken away the excavating-machine…”
Apparently, I had somehow called into an audiobook of The War of the Worlds. Suspicious of my clumsy fingers, I double-checked the number. It was correct (weird), but I tried the number again, figuring that at worst, I’d learn what happened after the Martians took away the excavating machine. This time, I got the initial error message and the call disconnected. No Martians.
This week, the U.S. president-elect spoke with the Pakistani prime minister and, according to the Pakistani government’s account of the conversation, delivered the following message: Everything is awesome. It was, arguably, the most surprising presidential phone call since George H.W. Bush got pranked by that pretend Iranian president.
Pakistan, Donald Trump reportedly told Nawaz Sharif, is a “fantastic” country full of “fantastic” people that he “would love” to visit as president. Sharif was described as “terrific.” Pakistanis “are one of the most intelligent people,” Trump allegedly added. “I am ready and willing to play any role that you want me to play to address and find solutions to the outstanding problems.”
The Daily Show host was measured, respectful, and challenging in his 26-minute conversation with TheBlaze pundit Tomi Lahren.
Tomi Lahren, the 24-year-old host of Tomi on the conservative cable network TheBlaze, feels like a pundit created by a computer algorithm, someone who primarily exists to say something provocative enough to jump to the top of a Facebook feed. She’s called the Black Lives Matter movement “the new KKK,” partly blamed the 2015 Chattanooga shootings on President Obama’s “Muslim sensitivity,” and declared Colin Kaepernick a “whiny, indulgent, attention-seeking cry-baby.” At a time when such charged political rhetoric feels increasingly like the norm, Lahren stands at one end of a widening gulf—which made her appearance on The Daily Show with Trevor Noah Wednesday night all the more fascinating.
In his first year at The Daily Show, Noah has struggled to distinguish himself in an outrage-driven late-night universe. He has sometimes seemed too flip about the failures of the country’s news media, something his predecessor Jon Stewart made a perennial target. Noah’s 26-minute conversation with Lahren, though, posted in its entirety online, set the kind of tone that Stewart frequently called for throughout his tenure. The segment never turned into a screaming match, but it also avoided platitudes and small-talk. Lahren was unapologetic about her online bombast and leaned into arguments that drew gasps and boos from Noah’s audience, but the host remained steadfastly evenhanded throughout. If Noah was looking for a specific episodethat would help him break out in his crowded field, he may have finally found it.
“A typical person is more than five times as likely to die in an extinction event as in a car crash,” says a new report.
Editor’s note: An earlier version of this story presented an economic modeling assumption—the .01 chance of human extinction per year—as a vetted scholarly estimate. Following a correction from the Global Priorities Project, the text below has been updated.
Nuclear war. Climate change. Pandemics that kill tens of millions.
These are the most viable threats to globally organized civilization. They’re the stuff of nightmares and blockbusters—but unlike sea monsters or zombie viruses, they’re real, part of the calculus that political leaders consider everyday. A new report from the U.K.-based Global Challenges Foundation urges us to take them seriously.
The nonprofit began its annual report on “global catastrophic risk” with a startling provocation: If figures often used to compute human extinction risk are correct, the average American is more than five times likelier to die during a human-extinction event than in a car crash.
"Dave, stop. Stop, will you? Stop, Dave. Will you stop, Dave?” So the supercomputer HAL pleads with the implacable astronaut Dave Bowman
in a famous and weirdly poignant scene toward the end of Stanley Kubrick’s
2001: A Space Odyssey. Bowman, having nearly been sent to a deep-space death by the malfunctioning machine, is calmly, coldly disconnecting the memory circuits that control its artificial “ brain. “Dave, my mind is going,” HAL says, forlornly. “I can feel it. I can feel it.”
I can feel it, too. Over the past few years I’ve had an uncomfortable sense that someone, or something, has been tinkering with my brain, remapping the neural circuitry, reprogramming the memory. My mind isn’t going—so far as I can tell—but it’s changing. I’m not thinking the way I used to think. I can feel it most strongly when I’m reading. Immersing myself in a book or a lengthy article used to be easy. My mind would get caught up in the narrative or the turns of the argument, and I’d spend hours strolling through long stretches of prose. That’s rarely the case anymore. Now my concentration often starts to drift after two or three pages. I get fidgety, lose the thread, begin looking for something else to do. I feel as if I’m always dragging my wayward brain back to the text. The deep reading that used to come naturally has become a struggle.
Critics say she failed to energize the Democratic base. But vote totals show her biggest shortcomings were in counties that opposed Barack Obama the most.
It now seems likely that Hillary Clinton will get fewer votes than Barack Obama did in 2012. More distressingly for Democrats, she fared worse in Democratic-leaning cities that anchor swing states, including Detroit, Cleveland, and Milwaukee. To critics on the left, that’s evidence of a campaign that dragged its feet, and a candidate who took her base for granted. Her defeat, in their minds, was an unforced error.
But the numbers show something different. There’s no question Clinton faltered in some Democratic cities, but the gaps between her haul and Obama’s in those locations were modest. The vast majority of her deficit came instead from counties that Obama lost in 2012: They didn’t like him, but they really hated her.