How many planets are out there?

You guys have to see this.

I didn’t know there was such a thing as the Kepler Mission happening. The Kepler satellite is part of NASA Discovery Mission #10, which aims to collect systematic data on the prevalence and size of planets orbiting other stars in the Milky Way. Kepler is equipped with a powerful telescope that has a very wide range of vision, which is pointed constantly at a particular range of space for four years. In that time, Kepler can monitor the spectral signatures of 100,000 and measure the deviation in brightness to detect the transit of a planet around the star. With such a large sample, the handlers expect to find something on the order of 50 planets, if most are the size of earth and perhaps 640 if planets tend to be much larger. Put simply, Kepler doesn’t just look for planets; it’s looking for data on the prevalence of planets.

But even if planets are common, who such a big sample size? There are all sorts of really delicious details on the link above, but this one knocked my socks off—

For a planet to transit, as seen from our solar system, the orbit must be lined up edgewise to us. The probability for an orbit to be properly aligned is equal to the diameter of the star divided by the diameter of the orbit. This is 0.5% for a planet in an Earth-like orbit about a solar-like star. (For the giant planets discovered in four-day orbits, the alignment probability is more like 10%.) In order to detect many planets one can not just look at a few stars for transits or even a few hundred. One must look at thousands of stars, even if Earth-like planets are common. If they are rare, then one needs to look at many thousands to find even a few. Kepler looks at 100,000 stars so that if Earths are rare, a null or near null result would still be significant. If Earth-size planets are common then Kepler should detect hundreds of them.

The picture below, from here, shows how sensitive Kepler’s output is relative to ground-based detection systems. The dip is the drop in light intensity as a planet transits a distant star.

a.j.m.

Filed under: Science, Space , kepler

What a bargain.

You’ve probably seen some of the new pictures from the Hubble, following its repair and upgrade during Hubble Servicing Mission 4, executed by the space shuttle Atlantis. But do you know just how impressive the upgrades were? A: Really impressive. This is humanity’s view of the Omega Centauri starfield, from 2002 and again from 2009.

And, lest we forget—the Hubble cost just $1.5 billion. What a phenomenal bargain.

a.j.m.

Filed under: Space , htsab, hubble

Powersat update!

Two space posts in one day?!

The Japanese government has invested $21 billion to create a gigawatt-scale solar installation in geosynchronous orbit capable of powering nearly 300,000 homes in Tokyo, by 2030. A small demonstration satellite is due to be launched in 2015, one year before Solaren, Inc.’s 200 MW structure is due to come online to satisfy its contract with California’s Pacific Gas & Electric utility. It’s hard to imagine this kind of macro-engineering project succeeding without government support, and so it’s disheartening to see Japan moving to underwrite the research more aggressively than the United States—but, gosh, exhilarating all the same!

The major impediment to powersat development seems still to be the prohibitive cost of launching that many tons of solar panel into orbit by rocket. The extensive wikipedia page on space-based solar power points out that NASA undertook a study on building solar panels from the moon or an asteroid in 1979, but perhaps the development of a more sustainable option like a space elevator or, better yet, a lofstrom loop might be required for the long term. In any case, both are highly speculative and to my knowledge there is no good solution to the problem of launch costs.

a.j.m.

Filed under: Space , powersat

One-way space flight.

The New York Times ran an interesting op-ed a couple of days ago asking: why spend so much money and effort developing a Mars expedition capable of bringing astronauts home again from Mars? Of course it’s a controversial claim, but not a ridiculous one. It has become commonplace to point out that a huge portion of NASAs budget is consumed by the development, testing, and repair of systems that allow people to go into orbit—one certainly disproportionate to the scientific benefit gained from human space flight. So if the aim of exploring Mars is for scientific discovery then surely robots can perform those simple experiments better than human astronauts could. If, on the other hand, you are of the opinion that there is more to be gained from Mars than a couple of tests (a new world for humans, for instance), then why not send Mars its first inhabitants? All civilizations of the world have sent hundreds of thousands explorers, adventurers, and scientists on expeditions from which they could not have reasonably expected return. And of course, no-one would have to coerce an American astronaut to accept a one-way ticket to Mars: why should we think that dying in the service of one’s country, science, and mankind is any more cruel than for an astronaut to die on Earth? The article points out that older astronauts could be sent to Mars, and that their years there could be made reasonably comfortable, undoubtedly fascinating, and motivated by the gratitude of an entire planet above them. And if they performed their jobs well, they might have every reason to hope for company soon. So why not? Why should something like this be a political nonstarter?

a.j.m.

Filed under: Space

Cosmic regulation.

Geoff Forden, over at ACW this past week, has put up some intuitive and informative graphs of the debris cloud that resulted from the  Iridium/Cosmos collision earlier in the month. The event is particularly notable for being the only collision to date between two intact satellites, and the fallout has been severe.

But Forden brings up the interesting point: for a company like Iridium, which knowingly faces the prospect of another such collision—is it cost-effective to build satellites with the maneuvering capacities and fuel reserves to shift their trajectories to avoid such a collision? How many times? Any company, naturally, would have to factor in the cost of the satellite plus the increased cost to the rest of their satellite network from the resulting debris (which they would presumably bear disproportionately).

What Forden only implies is that the externalities from such a collision would be enormous: the danger to other satellite constellations—public and private—and to larger public ventures like the ISS from 202 pieces of debris like the ones that resulted from the February collision would dwarf any risk to the company itself. The social scientific rubric will be immediately evident: spacefaring companies face a tragedy of the commons on a cosmic scale. As we tell all of our intro IR students, the solution is straightforward: governmental regulation steps in to internalize the externalities that a free-market would allow to persist. In this case, a solution would necessarily have to be some kind of global consortium that imposes standards on all launched public and private satellites for tracking and maneuvering capabilities. Such a project would presumably be legislated in conjunction with the kind of ‘Rules of the Road’ agreement that Michael Krepon, co-founder of the Stimson Center,  has repeatedly and cogently called for.

Filed under: Space , commons, debris, rules of the road, satellites

Just that one little satellite.

How often do you know about and hope for a satellite before it’s going to be launched? If you’re not a NASA mission controller or a niche scientist, not that often.

The OCO, NASA’s Orbiting Carbon Observatory satellite failed to separate from its launch vehicle this morning and will not become operational. The satellite was carrying complex and revolutionary sensors to track global patterns of Carbon dioxide emission and absorption, which would have given us a vastly greater understanding of the effects of weather patterns and the ability of carbon sinks like forests and oceans to absorb carbon dioxide. The results would have been invaluable to all of mankind. 

The one goddamn satellite I wanted. The last line of the article is particularly brutal.

Update: Here’s a longer article.

Filed under: Energy, Space

Asymmetries of care under democracy.

A continuing project of this page has been to trace some of the persistent pathologies that inhere in republican governments in the day to day goings on of our world. We have considered variously the tendency toward temporal myopia, populism, failures of the marketplace of ideas. Another is the proclivity to distribute risk adversity unevenly.

Consider the wildly divergent value assigned to different lives in different contexts: a child on state-provided health care; a soldier in Iraq; a child kidnapped; a murder in a school shooting; the one of us for every 460 of us who dies from largely preventable heart disease every year; of the nearly a gang shooting in an inner city; and so on. Consider the uneven evaluation of risk of return to certain technocratic ventures: the doomed superconducting supercollider; ground-based midcourse missile defense; upgrades to the power grid to transmit wind power; crop research; ocean science; wave power; laser weapons.

Consider the price paid for the life of an astronaut: astronomical sums for the development and attempted perfection of a crew module and life support capacities aboard the shuttle; the two and a half year gap in spaceflight after Columbia and the attendant costs to pay Russia to make up the gap in our ISS commitments; the extensive inspection each shuttle receives on return from orbit; and cetera.

Of course, I am not advocating standardization of all of these situations—utilitarianism is not a standard by which to weigh lives; we do have asymmetrical duties to certain citizens—but by any reasonable standard, our apportionment of resources, attention, and care is vastly distorted and inexplicable by any general rule [1]. Probably, the closest fitting rule would be a positive correlation between our attention to a given life and the scarcity of that life’s situation—which, it should be immediately clear, is not an ethical quantity of any appreciable value. A major liberal project is to advocate for an adjustment in this distribution of care, to shift resources further toward the wider base of the pyramid. I’ve always thought it exactly right to say that this is the primary moral imperative of society, and one we currently neglect.

But consider, too, an adjustment from the other end of the distribution. Peter Diamandis, the founder of the Ansari X-Prize, argued to the TED conference this year that more risk has to be acceptable in spaceflight. By any standard, this has to be true: given that these citizens are voluntarily in the public employ, in full cognizance of the risk they accept, our ethical duties to them are probably, strictly speaking, weaker than the ones we have to the millions that labor under the poverty imposed by our society’s tremendous inequality every day.

Democracies appear to be petrified of failure in some instances (space) but completely callous in other areas (weapons procurement). I have argued just below that global perception is of paramount importance to a country’s security and welfare—but this heterogeneity in risk aversion suggests that this standard is not an absolute one: if we’re trying to look strong, we would distribute our caution more evenly. More to the point, the distribution of our care is wildly counterproductive: what sort of image does it convey when we are absurdly casual with federal defense funds while being draconian about poverty programs—that our politics can’t bear the loss of sixteen humanitarian peacekeepers in Somalia (or even one in Kosovo) but tends not to notice 15,000 homicides each year, 3.8% of households that are food insecure, or an infant mortality rate of 6.85 per 1,000, well behind most European countries.

–a.j. mount

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[1] according to communal duties, psychic pain, or any other conceivable explicable rule.

Generally speaking, this does not allow for irrationality and downright perversity even within this rule: the marginal cost of adding an ejection system to the space shuttle (like the Russians did on Buran) would have been far less than that spent on checking the delicate heat shield on the bottom of the shuttle. Armoring soldiers in Iraq is another good example. This is a matter for another essay.

Filed under: Space, Who We Are , ethics, hysteria, priorities, the broader debate

Our limits on nationalism.

From a legal perspective, humanity sees nationalism almost as a virus. Our nations, in which we take pride and lend us community and opportunity, are bounded on all sides: by other nations, and normative prohibitions against the subversion of or expansionist attack against other nations (as in the U.N. Charter); by international waters, underwritten by Grotian mare liberum; by the Antarctic Treaty System to the South, which prohibits countries from promulgating or recognizing claims of sovereignty on that continent; and by the reaches of space above us, which the Outer Space Treaty of 1967 protects from ownership, parochialism, aggression, and even deception. The story of exploration in the last centuries has been one of restraint; as we have discovered new frontiers, we have placed ever stricter limits on national claims to subvert them. We commit ourselves to the political freedom of the space around us, and expand the global commons ever wider.

Of course, the cause of much of this body of jurisprudence has been the unwillingness to tilt the tenuous balance of power that prevails among our various corners of land—but I think it also depends on some basic recognition that nationalism cannot be infinite. (If these are not the proximate causes, the acceptance and durability of these treaties is probably acknowledgement of their normative import.) Alex Wendt has detailed internal logics of conflict that produce ever increasing levels of political aggregation—in the form of technologies of violence, and autonomy claims—but it is also worth recognizing that to some extent we have thrown our body of law ahead of ourselves.

We should remind ourselves that in the long-term—which is the term that matters most—our limitations on our own capabilities (in arms, in personal rights, in space) are our greatest assets and should be respected and maintained as such. Man will go into space, in search of material, knowledge, space, and wonder; if we are able to develop normative constraints now that cause us to leave our nations behind when we go will be maybe the greatest progressive achievement in the history of human civilization. The transition will be incredibly delicate and nations will face huge incentives to arrogate pieces of territory—but if we could resist…

It’s an easy enough next step to ask how we can promote normative constraints, but the answer is equally simple: steps toward the weaponization of space now, including a national missile defense system, start to degrade the commonality of space. If hegemony is distinguished from unipolarity and empire by a hegemon’s provision of common goods, American hegemony is only justifiable if it furthers common purposes; a parochial weaponization of space aimed at capturing relative gains from a global commons is in direct contrivance of this principle and should provoke resistance. It is an enormous responsibility to lead the international community at a time of such progress because it is we who have the most sway over the next order: if we mortgage the future of the earth to preserve our preponderance for a few short years, we will have failed this responsibility spectacularly.

Hegemony carries a responsibility to humanity.

Filed under: Arms Control, Space, the next order , law, limit, nationalism, wendt