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."
George Will is denouncing a GOP that has been ailing for years, but quitting won’t help—an American political party can only be reformed from within.
This past weekend, George Will revealed that he had formally disaffiliated himself from the Republican Party, switching his Maryland voter registration to independent. On Fox News Sunday, the conservative pundit explained his decision: "After Trump went after the 'Mexican' judge from northern Indiana then [House Speaker] Paul Ryan endorsed him, I decided that in fact this was not my party anymore.” For 40 years, George Will defined and personified what it meant to be a thoughtful conservative. His intellect and authority inspired a generation of readers and viewers, myself very much among them.
His departure represents a powerful image of divorce between intellectual conservatism and the new Trump-led GOP. Above all, it raises a haunting question for the many other Republicans and conservatives repelled by the looming nomination of Donald Trump as the Republican candidate for president of the United States: What will you do?
Hillary Clinton wrote something for The Toast today. Are you sobbing yet?
Either you’ll immediately get why this is crazy, or you won’t: Hillary Clinton wrote a thing for The Toast today.
Are you weeping? Did your heart skip a beat? Maybe your reaction was, “What. Whaaaat. WHAT,” or “Aaaaaaahhhhhhh!!!” or “OH MY GOD,” or simply “this is too much goodbye I'm dead now.”
Perhaps your feelings can only be captured in GIF form, as was the case for someone commenting on Clinton’s post under the name Old_Girl:
Reader comments like the ones above are arguably the best part of Clinton’s post, because they highlight just how meaningful hearing directly from Clinton is to The Toast’s community of readers. The Toast is a small but beloved feminist website known for its quirky literary humor. It announced last month it couldn’t afford to continue operating. Friday is its last day of publication.
“This western-front business couldn’t be done again.”
On this first day of July, exactly 100 years ago, the peoples of the British Empire suffered the greatest military disaster in their history. A century later, “the Somme” remains the most harrowing place-name in the annals not only of Great Britain, but of the many former dependencies that shed their blood on that scenic river. The single regiment contributed to the First World War by the island of Newfoundland, not yet joined to Canada, suffered nearly 100 percent casualties that day: Of 801 engaged, only 68 came out alive and unwounded. Altogether, the British forces suffered more than 19,000 killed and more than 38,000 wounded: almost as many casualties in one day as Britain suffered in the entire disastrous battle for France in May and June 1940, including prisoners. The French army on the British right flank absorbed some 1,600 casualties more.
On Wednesday on CNN, Marco Rubio said the Islamic State, which Turkish officials believe carried out this week’s attack at Istanbul’s Ataturk airport, had two motivations. First, “they ultimately want them to be a part of the caliphate.” Sure, but “ultimately,” ISIS wants every place on earth to be part of its caliphate. That doesn’t explain why the organization struck Turkey now. Rubio’s second explanation was more convincing: “They’re looking to punish Turkey for allowing U.S. airstrikes to be conducted from an airbase within Turkey. … They’ve made that abundantly clear.”
Yes, they have. ISIS may eventually wish to conquer the entire world. But in the here and now, it generally attacks countries that are attacking it. The Georgetown University terrorism expert Daniel Byman has noted that until the U.S. and its allies began bombing the Islamic State in the summer of 2014, the group “focused first and foremost on its immediate theater of operations” in Iraq and Syria. A study by the Norwegian Defence Research Establishment detected only four ISIS-related plots in the West from January 2011 to May 2014. Then, between July 2014 and June 2015, the number spiked to 26.
It happened gradually—and until the U.S. figures out how to treat the problem, it will only get worse.
It’s 2020, four years from now. The campaign is under way to succeed the president, who is retiring after a single wretched term. Voters are angrier than ever—at politicians, at compromisers, at the establishment. Congress and the White House seem incapable of working together on anything, even when their interests align. With lawmaking at a standstill, the president’s use of executive orders and regulatory discretion has reached a level that Congress views as dictatorial—not that Congress can do anything about it, except file lawsuits that the divided Supreme Court, its three vacancies unfilled, has been unable to resolve.
On Capitol Hill, Speaker Paul Ryan resigned after proving unable to pass a budget, or much else. The House burned through two more speakers and one “acting” speaker, a job invented following four speakerless months. The Senate, meanwhile, is tied in knots by wannabe presidents and aspiring talk-show hosts, who use the chamber as a social-media platform to build their brands by obstructing—well, everything. The Defense Department is among hundreds of agencies that have not been reauthorized, the government has shut down three times, and, yes, it finally happened: The United States briefly defaulted on the national debt, precipitating a market collapse and an economic downturn. No one wanted that outcome, but no one was able to prevent it.
For centuries, philosophers and theologians have almost unanimously held that civilization as we know it depends on a widespread belief in free will—and that losing this belief could be calamitous. Our codes of ethics, for example, assume that we can freely choose between right and wrong. In the Christian tradition, this is known as “moral liberty”—the capacity to discern and pursue the good, instead of merely being compelled by appetites and desires. The great Enlightenment philosopher Immanuel Kant reaffirmed this link between freedom and goodness. If we are not free to choose, he argued, then it would make no sense to say we ought to choose the path of righteousness.
Today, the assumption of free will runs through every aspect of American politics, from welfare provision to criminal law. It permeates the popular culture and underpins the American dream—the belief that anyone can make something of themselves no matter what their start in life. As Barack Obama wrote in The Audacity of Hope, American “values are rooted in a basic optimism about life and a faith in free will.”
In a 60-page ruling, a U.S. district-court judge stopped enforcement of a law providing religious exemptions for LGBT discrimination.
Why doesn’t anyone care about Mississippi?
This spring, the state’s legislature passed H.B. 1523, an extensive law written to protect people who believe any of the following: that marriage is between a man and a woman; that sex should only happen in the context of marriage; and that the words “male” and “female” refer to “an individual’s immutable biological sex as objectively determined by anatomy and genetics at time of birth.” The law claim these protections are a form of religious freedom.
It provides that religious organizations can refuse to rent out their social halls for a same-sex wedding, for example, and that clergy can refuse to perform a same-sex marriage ceremony. These groups can also fire a single mother who gets pregnant, or, in the case of religious adoption agencies, decline to place a child with a same-sex couple. Doctors and psychologists can refuse to get involved with gender-reassignment procedures or take cases that would violate their religious beliefs. Schools and other public agencies can create “sex-specific standards” for dress code, bathrooms, and more. State employees can also refuse to sign same-sex-marriage licenses, and they can’t be fired for saying they believe homosexuality is wrong, for example.
Sharing platforms are meant to scale seamlessly throughout the world, but they’ve faced a different knotty set of rules in nearly every city they’ve colonized.
For years now, Airbnb, the popular home-sharing platform, has featured this line of copy at the end of a company mission statement that mostly pledges to promote a sense of adventure and discovery: “And with world-class customer service and a growing community of users, Airbnb is the easiest way for people to monetize their extra space and showcase it to an audience of millions."
It’s a business model condensed into a coda, casually set off with an “And.” The subtext is that the revenue-making potential of the platform is an afterthought, which implies that its appeal lies in its ease of use. Sign up and rent out your apartment or guest room. It’s easy.
Easy, that is, unless you live in Chicago, where regulations passed last week will require hosts to register with the city, impose a tax on each transaction to pay for the city’s homeless services, and limit the number of apartments that can be rented out in a particular building, depending on its size. Or in San Francisco, Airbnb’s hometown, where a law that went into effect in 2015 limits the total number of days an apartment can be rented out per year and similarly requires hosts to register with the city. (This week, the company, which coincidentally helped draft the 2014 law, decided to sue the city over it.) Months after San Francisco imposed those limits, Santa Monica passed regulations requiring hosts to get business licenses and restricted them from renting out entire properties.
They say religious discrimination against Christians is as big a problem as discrimination against other groups.
Many, many Christians believe they are subject to religious discrimination in the United States. A new report from the Public Religion Research Institute and Brookings offers evidence: Almost half of Americans say discrimination against Christians is as big of a problem as discrimination against other groups, including blacks and minorities. Three-quarters of Republicans and Trump supporters said this, and so did nearly eight out of 10 white evangelical Protestants. Of the latter group, six in 10 believe that although America once was a Christian nation, it is no longer—a huge jump from 2012.
Polling data can be split up in a million different ways. It’s possible to sort by ethnicity, age, political party, and more. The benefit of sorting by religion, though, is that it highlights people’s beliefs: the way their ideological and spiritual convictions shape their self-understanding. This survey suggests that race is not enough to explain the sense of loss some white Americans seem to feel about their country, although it’s part of the story; the same is true of age, education level, and political affiliation. People’s beliefs seem to have a distinctive bearing on how they view changes in American culture, politics, and law—and whether they feel threatened. No group is more likely to express this fear than conservative Christians.
The relationship therapist Esther Perel thinks so—and argues that it’s time to rethink matrimony and, with it, infidelity.
Think of the last wedding you attended. Did the couple’s vows to each other involve promises to be, for the rest of their lives, friends and family and companions and lovers and allies? Did the two people vow to keep exciting each other and soothing each other and listening to each other and challenging each other, to be co-adventurers and co-Netflixers and co-owners of things and possibly co-parents of things and, all in all, pretty much all things to each other?
If so, the couple is very modern. Marriage has spent most of its existence, in the West and elsewhere, as primarily an economic arrangement; as a result, it has also spent most of its existence much less laden with the emotional expectation that we tend to heap upon it today. The current romantic conception of marriage—evident in the culture not just in the guise of hopeful wedding vows, but also in the wedding industrial complex and in pretty much every Hollywood rom-com that defines its “happy ending” according to the satisfactions of long-term commitment—is the result of historical coincidence. It arose, the Belgian relationship therapist Esther Perel argues, from a collision of several forces that collided in the 19th and 20thcenturies: among them capitalism, latent Romanticism, and the political and cultural notion of the primacy of the individual.