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."
Even when they’re adopted, the children of the wealthy grow up to be just as well-off as their parents.
Lately, it seems that every new study about social mobility further corrodes the story Americans tell themselves about meritocracy; each one provides more evidence that comfortable lives are reserved for the winners of what sociologists call the birth lottery. But, recently, there have been suggestions that the birth lottery’s outcomes can be manipulated even after the fluttering ping-pong balls of inequality have been drawn.
What appears to matter—a lot—is environment, and that’s something that can be controlled. For example, one study out of Harvard found that moving poor families into better neighborhoods greatly increased the chances that children would escape poverty when they grew up.
While it’s well documentedthat the children of the wealthy tend to grow up to be wealthy, researchers are still at work on how and why that happens. Perhaps they grow up to be rich because they genetically inherit certain skills and preferences, such as a tendency to tuck away money into savings. Or perhaps it’s mostly because wealthier parents invest more in their children’s education and help them get well-paid jobs. Is it more nature, or more nurture?
On “Back to Back Freestyle” and “Charged Up,” the rapper forgoes the high road in his beef with Meek Mill.
Once upon a time, Drake made a vow of silence. “Diss me, you'll never hear a reply for it,” he said on “Successful,” the 2009 song in which the Toronto rapper correctly predicted he’d soon be superwealthy. This week, Drake has broken his vow twice over, a fact about which he seems conflicted. “When I look back,” he says on the new track “Back to Back Freestyle,” “I might be mad that I gave this attention.”
“This” is the beef started by the 28-year-old Philadelphia rapper Meek Mill, who recently tweeted accusations that Drake doesn’t write his own material. Depending on who you talk to or how you look at it, this is either a big deal or no deal at all. On Instagram, Lupe Fiasco had a good take: “Ghostwriting, or borrowing lines, or taking suggestions from the room has always been in rap and will always be in rap. It is nothing to go crazy over or be offended about unless you are someone who postures him or herself on the importance of authenticity and tries to portray that quality to your fans or the public at large. Then we might have a problem.”
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.
Jim Gilmore joins the race, and the Republican field jockeys for spots in the August 6 debate in Cleveland.
After decades as the butt of countless jokes, it’s Cleveland’s turn to laugh: Seldom have so many powerful people been so desperate to get to the Forest City. There’s one week until the Republican Party’s first primary debate of the cycle on August 6, and now there’s a mad dash to get into the top 10 and qualify for the main event.
With former Virginia Governor Jim Gilmore filing papers to run for president on July 29, there are now 17 “major” candidates vying for the GOP nomination, though that’s an awfully imprecise descriptor. It takes in candidates with lengthy experience and a good chance at the White House, like Scott Walker and Jeb Bush; at least one person who is polling well but is manifestly unserious, namely Donald Trump; and people with long experience but no chance at the White House, like Gilmore. Yet it also excludes other people with long experience but no chance at the White House, such as former IRS Commissioner Mark Everson.
The Vermont senator’s revolutionary zeal has met its moment.
There’s no way this man could be president, right? Just look at him: rumpled and scowling, bald pate topped by an entropic nimbus of white hair. Just listen to him: ranting, in his gravelly Brooklyn accent, about socialism. Socialism!
And yet here we are: In the biggest surprise of the race for the Democratic presidential nomination, this thoroughly implausible man, Bernie Sanders, is a sensation.
He is drawing enormous crowds—11,000 in Phoenix, 8,000 in Dallas, 2,500 in Council Bluffs, Iowa—the largest turnout of any candidate from any party in the first-to-vote primary state. He has raised $15 million in mostly small donations, to Hillary Clinton’s $45 million—and unlike her, he did it without holding a single fundraiser. Shocking the political establishment, it is Sanders—not Martin O’Malley, the fresh-faced former two-term governor of Maryland; not Joe Biden, the sitting vice president—to whom discontented Democratic voters looking for an alternative to Clinton have turned.
Today's cities may be more diverse overall, but people of different races still don’t live near each other.
Nearly 50 years ago, after a string of race-related riots in cities across America, President Lyndon B. Johnson commissioned a panel of civic leaders to investigate the underlying causes of racial tension in the country.
The result was the Kerner Report, a document that castigated white society for fleeing to suburbs, where they excluded blacks from employment, housing, and educational opportunities. The report’s famous conclusion: “Our nation is moving toward two societies, one black, one white—separate and unequal.”
Much of America would like to believe the nation has changed since then. The election of a black President was said to usher in a “post-racial era.” Cheerios commercials nowfeature interracial couples. As both suburbs and cities grew more diverse, more than one academic study trumpeted theend of segregation in American neighborhoods.
Three decades after the FBI launched a revolutionary system to catch repeat offenders, it remains largely unused.
QUANTICO, Virginia—More than 30 years ago, the Federal Bureau of Investigation launched a revolutionary computer system in a bomb shelter two floors beneath the cafeteria of its national academy. Dubbed the Violent Criminal Apprehension Program, or ViCAP, it was a database designed to help catch the nation’s most violent offenders by linking together unsolved crimes. A serial rapist wielding a favorite knife in one attack might be identified when he used the same knife elsewhere. The system was rooted in the belief that some criminals’ methods were unique enough to serve as a kind of behavioral DNA—allowing identification based on how a person acted, rather than their genetic make-up.
Equally as important was the idea that local law-enforcement agencies needed a way to better communicate with each other. Savvy killers had attacked in different jurisdictions to exploit gaping holes in police cooperation. ViCAP’s “implementation could mean the prevention of countless murders and the prompt apprehension of violent criminals,” the late Senator Arlen Specter wrote in a letter to the Justice Department endorsing the program’s creation.
During the multi-country press tour for Mission Impossible: Rogue Nation, not even Jon Stewart has dared ask Tom Cruise about Scientology.
During the media blitz for Mission Impossible: Rogue Nation over the past two weeks, Tom Cruise has seemingly been everywhere. In London, he participated in a live interview at the British Film Institute with the presenter Alex Zane, the movie’s director, Christopher McQuarrie, and a handful of his fellow cast members. In New York, he faced off with Jimmy Fallon in a lip-sync battle on The Tonight Show and attended the Monday night premiere in Times Square. And, on Tuesday afternoon, the actor recorded an appearance on The Daily Show With Jon Stewart, where he discussed his exercise regimen, the importance of a healthy diet, and how he still has all his own hair at 53.
Stewart, who during his career has won two Peabody Awards for public service and the Orwell Award for “distinguished contribution to honesty and clarity in public language,” represented the most challenging interviewer Cruise has faced on the tour, during a challenging year for the actor. In April, HBO broadcast Alex Gibney’s documentary Going Clear, a film based on the book of the same title by Lawrence Wright exploring the Church of Scientology, of which Cruise is a high-profile member. The movie alleges, among other things, that the actor personally profited from slave labor (church members who were paid 40 cents an hour to outfit the star’s airplane hangar and motorcycle), and that his former girlfriend, the actress Nazanin Boniadi, was punished by the Church by being forced to do menial work after telling a friend about her relationship troubles with Cruise. For Cruise “not to address the allegations of abuse,” Gibney said in January, “seems to me palpably irresponsible.” But in The Daily Show interview, as with all of Cruise’s other appearances, Scientology wasn’t mentioned.
“If nobody respected the Taliban leadership anymore,” said one analyst, “then you have no one to talk to.”
Reports on Wednesday that reclusive Taliban leader Mullah Omar had died will be rightly hailed by some as the demise of an American nemesis. But the death of the one-eyed Afghan commander may also scuttle the most promising peace talks in Afghanistan in a decade.
Omar’s direct role in day-to-day Taliban operations had been declining for years, according to Western diplomats in Afghanistan. Even if he is alive, the former leader of Afghanistan is believed to be severely ill.
But the myth that surrounds Omar is a key element in determining whether peace talks can succeed. With the Islamic State and other jihadist groups vying for the loyalty of young Taliban fighters, it is unclear whether any leader except Omar can hold the movement together and then get its members to accept a peace settlement.
When a young person dies unexpectedly, his or her family could end up with the burden of paying off student loans. Can that be avoided?
What would happen to all of your debt if you died?
That’s a morbid question, but it’s a pretty important one, even for young adults. Back in 2012, ProPublica told the story of Francisco Reynoso, a gardener from Palmdale, California, whose son was killed in a car accident on the way home from a job interview. Reynoso, who made $21,000 a year, was held liable for paying off his son’s student-loan debt, which numbered in the six figures.
Reynoso’s story is, unfortunately, not a unique one. Millennials are the most educated generation yet, but with all those degrees has come a mountain of debt. On top of that, a shaky economy and changing views of work mean many young adults are working as freelancers or contractors, positions that often don’t come with the benefits that can help families cope with financial burdens should something bad happen.