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."
The Commission on Presidential Debates issued a cryptic statement acknowledging some audio issues Monday night.
After critics savaged his performance at Monday’s first presidential debate, Republican nominee Donald Trump alighted on several culprits: Hillary Clinton, the moderator, and especially his microphone.
The claim was met with some skepticism, but on Friday afternoon, the Commission on Presidential Debates seemed to confirm his claim, at least in part. The commission, which controls the debates, released a cryptic statement that reads in full:
Statement about first debate
Sep 30, 2016
Regarding the first debate, there were issues regarding Donald Trump's audio that affected the sound level in the debate hall.
We’ve called the commission to ask what that means, but have not heard back yet. Presumably, they are receiving dozens of such queries.
The Trump Foundation mostly takes in other people’s money, but it appears it doesn’t have legal permission to solicit donations.
The problem with telling people to follow the money is they just might take you up on it. Donald Trump’s campaign has adopted that mantra in reference to the Clinton Foundation, but it applies to him in uncomfortable ways, too.
First, there’s the fact that he won’t release his tax returns, making it hard to follow the money and raising questions about what might be hidden there. Second, there are his forays into Cuba, apparently in violation of the embargo. Third, there’s the latest scoop from The Washington Post’s David Fahrenthold, who finds that the Donald J. Trump Foundation was operating without a required license.
As Fahrenthold previously reported, the Trump Foundation is peculiar: Unlike many other similar charities, it’s stocked with other people’s money. Trump himself has given barely any money to it since the mid-2000s, although he did direct income from places like Comedy Central to the charity, possibly without paying taxes on it. Instead, he has raised money from other donors, which he has used to, among other things, settle legal cases against him, all while basking in the glow of his apparent charity.
Across the country, Republican-leaning papers are breaking with their own history to warn their readers about the GOP nominee.
There is a lot of truth to the stereotype that the American media is centered in New York City and Washington, D.C., staffed by Democrats, and hostile to Republicans. Like other professionals, journalists run the gamut from hugely talented individuals doing great work to hacks producing crap, but journalism is unusual in its dearth of ideological diversity.
Simply by living 3,000 miles from the East Coast, leaning more libertarian than progressive, and opposing President Obama’s reelection, I am an outlier in my field. And neither my upbringing among Republicans I respect deeply nor my many differences with leftism gives me insight into what daily life is like in the vast swaths of the country where I’ve never lived or the many jobs I’ve never worked. So I get why tens of millions of Americans don’t give a damn what distant network news anchors with seven-figure net worths think about this election, or that the New York Times, which always endorses the Democratic nominee, endorsed Hillary Clinton.
An etiquette update: Brevity is the highest virtue.
I recently cut the amount of time I spent on email by almost half, and I think a lot of people could do the same.
I’m sure my approach has made some people hate me, because I come off curt. But if everyone thought about email in the same way, what I’m suggesting wouldn’t be rude. Here are the basic guidelines that are working for me and, so, I propose for all of the world to adopt immediately:
Best? Cheers? Thanks?
None of the above. You can write your name if it feels too naked or abrupt not to have something down there. But it shouldn’t, and it wouldn’t if it were the norm.
Don’t waste time considering if “Dear,” or “Hey” or “[name]!” is appropriate. Just get right into it. Write the recipient’s name if you must. But most people already know their names. Like they already know your name.
Lawmakers overrode an Obama veto for the first time on Wednesday. A day later, they already had regrets.
The enactment on Wednesday of the Justice Against Sponsors of Terrorism Act should have been a triumphant moment for Republican leaders in Congress. They had succeeded, after years of trying, in overriding a presidential veto for the first time and forcing a bill into law over the strenuous objections of Barack Obama.
But the morning after brought no such celebration for HouseSpeaker Paul Ryan and Senate Majority Leader McConnell—only pangs of regret.
“It appears as if there may be some unintended ramifications,” McConnell lamented at a press conference barely 24 hours after all but one senator voted to reject the president’s veto of the legislation, which would allow victims of the September 11, 2001 terrorist attacks to sue Saudi Arabia in U.S. court. On the other side of the Capitol, Ryan said that he hoped there could be a “fix” to the very law he allowed to pass through the House—one that would protect U.S. soldiers abroad from legal retribution that the Obama administration had warned for months would follow as a result of the law.
With the death of Shimon Peres, Israel has lost its chief optimist. And the prime minister remains paralyzed by pessimism.
The Book of Proverbs teaches us that where there is no vision, the people perish. The people of Israel, now bereft of Shimon Peres, will not perish, because survival—or, at least, muddling through—is a Jewish specialty. But the death of Israel’s greatest visionary, a man who understood that it would never be morally or spiritually sufficient for the Jews to build for themselves the perfect ghetto and then wash their hands of the often-merciless world, means that Israel has lost its chief optimist.
Peres was, for so many years, a prophet without honor in his own country, but he was someone who, late in life, came to symbolize Israel’s big-hearted, free-thinking, inventive, and democratic promise. Peres came to this role in part because he had prescience, verbal acuity, a feel for poetry, and a restless curiosity, but also because, gradually but steadily, he became surrounded by small men. One of the distressing realities of Israel today is that, in so many fields—technology, medicine, agriculture, literature, music, cinema—the country is excelling. But to Israeli politics go the mediocrities.
They’re not transparent. They’re not independent. They’re not even turned on when they should be.
When they were introduced to the American public two years ago, police body-cameras seemed like they might help everyone. Police departments liked that body cams reduced the number of public complaints about officer behavior. Communities and protesters liked that they would introduce some transparency and accountability to an officer’s actions.
Today, research suggests that body cameras significantly reduce the number of public complaints about police. But recent events subvert the idea that the devices help or increase the power of regular people—that is, the policed. Instead of making officers more accountable and transparent to the public, body cameras may be making officers and departments more powerful than they were before.
Despite an array of calculating tools, comparing financial-aid packages is still an incredibly dense and circular process.
As almost any parent of a high-school senior knows, figuring out the true college price tag is confusing. While the full annual sticker price can be as much as $60,000 or $70,000 at a private college and more than $55,000 at an out-of-state public college, experts say that many students will end up paying considerably less. Sizable merit and need-based aid packages take the sting out of those big numbers.
Students, however, typically have to wait until the spring, when their acceptance letters arrive, to learn the amount of those awards, making it difficult for families to effectively plan a long-term budget and posing significant obstacles for first-generation students who may not be aware of all the financial options.
After Andrea Wulf won the Royal Society’s highest honor for her book The Invention of Nature, a writer at The Guardian attributed it to a new fondness for “female-friendly” biographies among prize juries.
Last week, the Royal Society held its ceremony to honor the best popular-science book of the year. I was there, having had the good fortune to be one of the finalists for my recent book, The Hunt for Vulcan. I didn’t expect to win—partly because of my baseline pessimism, partly because of the strength of the competition, and partly because I had set out to write a kind of miniature, a brief book on a quirky topic. Whatever the reason, I was right: I didn’t.
The event itself was good fun. Each of the authors read a passage from their work; the head judge for the prize, author Bill Bryson, led us in a brief question-and-answer session, in which we compared notes on what moved us to write about science. Then came the moment of truth. Venkatraman Ramakrishnan, the president of the Royal Society, approached the podium, opened the envelope, and announced that Andrea Wulf had won for The Invention of Nature.