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Quantifying the Risk of Damage to Integrated Circuits in Space

The dangers that electronics face in space from energetic charged particles emitted by the sun are pretty big. How big? Glad you asked. A researcher at Boeing has developed new computer-aided design software designed to help quantify the risk space weather can pose.

The perils related to geomagnetic storms were made painfully clear in 1989 when such a storm blacked out the entire Canadian province of Quebec within seconds. It left six million customers in the dark for nine hours, damaging transformers as far away as New Jersey, and nearly taking down U.S. power grids from the mid-Atlantic through the Pacific Northwest. Moreover, geomagnetic storms 10 times as strong are possible. One such event was the 1859 solar superstorm.

The risk of damage to electronics from space weather is even greater for satellites in orbit and spacecraft dispatched to other planets—areas far outside Earth's protective envelope. Designing circuits for use in space has to account for such dangers, but quantifying this risk has proven difficult.

Now William Atkinson at Boeing has developed software known as TSAREME (short for Total Space and Atmospheric Radiation Effects on Microelectronics) to account for errors induced by the impact of radiation in near-Earth orbits and inside the atmosphere. Atkinson will describe his invention in detail on 12 April at a meeting of the American Physical Society in Baltimore.

For electronics meant to be used in space, TSAREME computes the effects of strikes by protons, alpha particles, and other high-energy particles made of elements as heavy as iron. Inside the atmosphere, TSAREME models the effects of charged particles interacting with air molecules. That allows the software to account for how the magnetosphere, the bubble of plasma around Earth controlled by the planet's magnetic field, can vary with latitude.

The software analyzed satellite measurements of solar flares over a four-year period to test a variety of electronic designs with feature sizes varying from 1 micrometer down to to 15 nanometers. It found that there are a number of alternatives to conventional CMOS ICs that significantly reduce the risk of electronic disruptions in space. Among these are silicon germanium, silicon-on-insulator, and silicon-on-sapphire technologies. 

Intel and Micron Move 3-D NAND Into Production

The race to build 3-D memories is starting to heat up. 

Last week, Intel and Micron announced they have developed a 3-D NAND memory with 32 layers that they expect to mass produce later this year. (That’s 31 layers more than most flash on the market.) 

Intel billed the memory as the world’s highest-density flash, capable of creating gumstick-sized solid-state drives with more than 3.5 terabytes of storage. The announcement was hot on the heels—by a matter of hours—of news from Toshiba, which collaborates with SanDisk, that it too has begun sending out samples of 3-D NAND chips.

3-D, or vertical, NAND is flash memory that’s been turned on its side. Instead of laying down bits on the surface of a chip, chipmakers arrange the bit lines vertically, in a forest of pillars.

In the past, I’ve called this a “right turn around Moore’s Law”, since it’s a way to get around the difficulties chipmakers are facing in shrinking memory cells. By extending memory into the third dimension, engineers can pack more bits into the same area without having to make those bits any smaller, much like a real-estate developer might hope to pack people into high-rises instead of single family homes. 

The announcements suggest that flash manufacturers have largely overcome the main technical hurdles to making the switch to the 3-D structures. But analyst Jim Handy of Objective Analysis in Los Gatos, Calif., who has been covering 3-D NAND in depth on his website, advises taking the delivery dates that companies have been giving with a grain of salt.  

It’s likely these companies are trying to close the lead with Samsung, which started shipping 3-D NAND chips last year. Intel and Micron’s “public announcement comes from the enormous pressure these guys feel from Samsung’s actions,” Handy says. “Since Samsung is shipping, and beating the 3-D drum at every opportunity, the other flash makers look like they are falling behind.”

But while, Samsung might have been early out of the gate, he says, it has probably been producing those chips at a loss. The company began shipping chips so early, it’s possible that the company might not have worked the kinks out of its manufacturing process. That would mean a fairly low fraction of its 3-D flash chips are workable, making them more expensive than the 2-D version.  “Samsung has elected to ship [3-D NAND] prior to its becoming economical,” Handy says. “This is helping the company bolster its reputation as a technology leader.”

Handy says the difficulty in making the switch could mean 3-D NAND might not be economical until 2017. The question is whether companies will choose to push forward with the memory regardless, or wait until the manufacturing process is more mature. 

“I don’t think that Intel and Micron are close to being economical yet, but they are optimistic that they will reach that point next year,” Handy says. “I am pessimistic, since [I’ve seen] significantly simpler transitions cause delays of a year or longer.”

What Happens If Russia Abandons the International Space Station?

For fifty years, NASA prepared for space missions as if for battle: practice repeatedly what you must do, prepare to be surprised, and have backup plans when you are, because you will be. But now with America’s space future at stake, that principle appears to have weakened, and NASA may have overlooked something crucial.

On March 4, during testimony before a U.S. House Appropriations subcommittee, NASA administrator Charles Bolden was asked about what happens if the Russians pull out of the International Space Station. (Critical ISS modules are Russian, and currently the only way for humans to travel between the ISS and the ground is via Russian Soyuz spacecraft.) Asked by the new chairman, John Culberson, about what would happen in the event that Vladimir Putin’s current belligerency ever led to Russia refusing to fly Americans to the space station, Bolden stated that it would be impossible for either Russia or America to operate the station without the other. Pressed by Culberson about NASA contingency plans, Bolden said  “You are forcing me into this answer, and I like to give you real answers,” then adding “I don't want to try and BS anybody.” But, in the end, told the committee, “We would make an orderly evacuation.”

That’s it—we’d have time to pack and turn out the lights.

That’s the wrong answer. But Culberson’s question was wrong too, narrowly focused as it was on Kremlin perfidy. Many scenarios could cripple Russia’s ability to fly crews to the ISS. The Russians could be victimized by technical problems with launch vehicles, suffer diplomatic problems with the Soyuz launch site (which is located in Khazakastan, a country concerned about what’s been happening in Ukraine), be subject to terrorist attacks on ground infrastructure, or suddenly have to cope with age- or human-error-induced crippling of one of their station modules. Exactly what NASA and its other partners would have to do in response to any of these scenarios would deeply depend on the specific nature of the loss of function.

So to learn that NASA has spent no thought on what to do in the face of this wide gamut of possible events is disturbing. Past space disasters—such as Apollo 13’s liquid-oxygen tank explosion, Skylab’s crippling launch mishaps, and the misshapen Hubble telescope mirror—were overcome in large part because space planners had anticipated categories of failures and had then outlined response plans, albeit often with the details left to be filled in as needed.

But apparently not this time, with the most expensive and irreplaceable space station the world has ever seen? Let me suggest some half-baked answers as a starting point.

The problem of getting a US crew to the station is approaching resolution, with operational missions of commercial crew transportation vehicles from SpaceX and Boeing two or three years away. That date is budget-driven and with emergency funding could be moved significantly sooner.

Meanwhile, even if no new astronauts can be sent to the ISS, those already aboard would be able to hunker down and extend their stay significantly. It would bend and even break current medical limits (which have only recently been extended to permit a one-year stay on the station for Mikhail Kornienko and Scott Kelly, who blasted off for the ISS last Friday) but it would be an emergency response.

The remaining safety issue would be the problem of conducting an emergency evacuation in the case that one or both of the two Soyuz spacecraft normally docked at the station were unavailable. Even here, there are conceivable short-term modifications to existing cargo vehicles, such as SpaceX’s Dragon capsule, that could provide an acceptable crew return ability with bare-bones life support.

This would incur significant risks. But they would have to be balanced against the enormously greater risk posed abandoning the station in the face of a breakdown of cooperation between America and Russia. Most of that risk would be in the form of the consequent unavoidable random impact of a million pounds of station debris somewhere on Earth.  The station cannot be safely de-orbited into open ocean without the Russians.

Keeping the ISS in orbit, then, would the next major operational challenge.

The station now flies at about 400 kilometers altitude. This is low enough that there is slight but measurable air drag that inexorably lowers the ISS’s altitude, requiring regular reboosts. There are engines for this purpose on the Russian modules, but, whenever possible, reboosts are performed using the engines of docked supply ships, mostly Russian in make but occasionally European as well (although that European series of vehicles has recently finished all their scheduled flights).

Depending on solar activity (which can inflate the atmosphere) it would take perhaps a year or slightly more for the orbit of the ISS to irreversibly decay. Some short-term techniques, such as reducing air drag by feathering the solar arrays would, at significant cost in power generation, extend that lifetime somewhat.

Absent the Russians then, NASA would have to find a new ‘tug’ vehicle—one that could reach the station and dock at place where it’s safe to apply thrust—within the space of a year. It’s probably the long pole in the “Save the ISS” tent. (Bear in mind that it was originally thought that the space shuttle would be flying in plenty of time to reboost the Skylab space station. That didn’t end too well for Skylab.)

The challenge is that the ISS is so massive that currently available American upper stages can’t carry enough propellant to push the station into a higher orbit. Perhaps a European tug, thrown together from spare parts, could be readied in time. Perhaps the magicians at SpaceX or other commercial space shops could whip together a series of smaller tugs, one after the other.

Or even more original ideas (desperate ideas for desperate times) might work out, if thought about and ground-tested early enough. There are proposals for continuous-thrusting ion engines, some well into bench testing, for example. Surely it would be prudent for NASA to survey and catalog these long shots before the crisis actually arrives?

There’s even a crazy idea reminiscent of the Russian tale of winter sleigh travelers pursued by wolves, stretching their lives by tossing the smallest guy out of the sled. In this scheme, ISS astronauts would detach a station module or two (at enormous effort in terms of spacewalks). Each module would be tied to a long Kevlar tether to dangle down 100 km beneath the station, and then the tether would be cut. The module would fall to a controlled atmospheric burnup while—thanks to conservation of momentum—throwing the station significantly higher.

Without a real propulsion system, however, the ISS wouldn’t be able to make debris avoidance burns, needed several times a year to reduce collision hazards. So for longer term operations, at some point a new permanent thruster module would need to be added.

 No question this challenge would be hard. But to hear a NASA leader tell the world that that’s a reason not to even try—not to take a risk, even with volunteers—is a reversal of time-honored toughness, competence, and ingenuity that gave us the Moon, and given us the potentially-threatened space outpost that is paving the way outwards far beyond it. 

NASA Details 2020s Asteroid Capture Mission

Since 2012, NASA has been trying to figure out how to capture an asteroid and bring it back to Earth. This is a good idea for a bunch of reasons, but there are two big ones (according to NASA). First, the mission will help develop technologies that could be used to redirect an asteroid that’s on a collision course with Earth.  And, second, snagging an asteroid and dragging it into lunar orbit so a manned spacecraft can poke around it will be a useful way to prepare humans for deep-space travel, eventually, to Mars.

Last week, NASA announced a much more detailed plan of exactly what this asteroid redirect mission will entail. As expected, it’s a bit more conservative than the original concept for the mission, but with (the agency hopes) a substantially better chance of success.

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Chip Could Double Wireless Data Capacity

A new microchip could double the amount of data one can transmit and receive wirelessly by enabling simultaneous transmission and reception on the same radio frequency, engineers at Columbia University say.

This advance could not only improve portables and WiFi networks, "but this could also ease up the frequency spectrum as well," says Harish Krishnaswamy, an assitant professor of electrical engineering at Columbia University, in New York City.

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ESA Tests Satellite-Snagging Nets for Orbital Trash Removal

Space junk is a serious problem, and not just in the movies. While avoiding the creation of space junk in the first place by designing spacecraft from the beginning to deorbit themselves is probably the most realistic long-term solution, the interim may require active measures to mitigate some of the trash that's already up there.

The European Space Agency has been developing a mission to capture and deorbit a piece of debris, and their latest test involves launching weighted anti-junk nets in microgravity.

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Electromagnetic Arc Generator Could Protect Against Shockwaves with Plasma

Over the past few millennia, we humans have been steadily perfecting more and more violent ways of hurting each other. At the same time, we've been almost as steadily perfecting more and more reliable ways of protecting ourselves.

We’re at the point where physical barrier technologies are capable of stopping most projectile weapons, so predictably, weapons that rely on shockwaves (that can pass through physical barriers) are becoming more prevalent. In response to this, Boeing has filed a patent on a system that can mitigate or prevent damage from an incoming shockwave, using electromagnetic arc generators. Here’s how it works.

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Iceland's Giant Genome Project Points to Future of Medicine

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When the first Viking explorers began settling Iceland, none could have imagined that their descendants would pioneer the future of modern medicine by surveying the human genome. Fast forward 1000 years to today, when an Icelandic company has revealed its success in sequencing the largest-ever set of human genomes from a single population. The new wealth of genetic data has already begun changing our understanding of human evolutionary history. It also sets the stage for a new era of preventive medicine based on individual genetic risks for diseases such as cancer and Alzheimer’s disease.

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Path to Better OLEDs, Organic Solar Cells Found

Researchers say they might have a way to  significantly enhance the performance of  organic light-emitting diodes (OLEDs) and some kinds of solar cells. They’ve discovered how to precisely order the molecules that make up the organic glasses that serve as the active semiconductor components in these devices.

Glasses are solids that lack the regular order of crystals. The most familiar kind of glass is based on silica, but other kinds of glass exist as well, such as organic glasses based on carbon.

Although one might expect the disorderly structure of glasses to orient their molecules in no particular direction, recent studies have found that molecules in organic glasses can be oriented in specific ways. This orientation can improve the efficiency and lifetime of the devices they are used in.

Organic glasses are typically produced in vacuum chambers from vapors that condense in thin films on a substrate. Now researchers find the substrate temperature is the key factor behind controlling molecular orientation within those glasses.

Scientists at the University of Wisconsin-Madison and the University of Chicago investigated the effect of substrate temperature on glasses of three organic semiconductors often used in electronics. They found they could easily and routinely impose order on these organic glasses by controlling substrate temperature, and that all three molecules could produce glasses with high levels of molecular orientation. The molecular orientation that results in the glasses is a remnant of the molecular orientation present in a liquid layer that can form on the substrate.

The researchers suggest these findings could optimize the performance of nearly any device based on organic glasses. They detailed their findings online 23 March in the journal Proceedings of the National Academy of Sciences.

Controlling Qubits in Silicon at Picosecond Speeds

Among the many candidates for storing quantum bits, or qubits, are electrons, atoms, molecules and quantum dots. However, over the last few years, researchers have been focusing on storing quantum bits in silicon as a promising avenue towards realizing a quantum computer. Now, researchers from the University of Surrey, University College London, Heriot-Watt University in Edinburgh, the Radboud University in Nijmegen, and ETH Zürich/EPF Lausanne/Paul Scherrer Institute in Switzerland have reported the ability to control the quantum state of qubits embedded in silicon and readout the result by a simple electrical measurement. A paper describing their findings appears in the 20 March edition of Nature Communications

The qubits are phosphorus atoms trapped inside the silicon layer. Because the spin state of the outer electron of these atoms can remain in a state of superposition of the two possible spin states, these qubits are therefore called “orbital qubits.” They can retain a superposition state for a fraction of a millisecond before they are disrupted. The researchers demonstrated that they could switch the quantum state of the phosphorus atoms with laser pulses in about a picosecond (10-12 s), which is a thousand times faster than achieved with previous similar experiments. The advantage of these short pulses is that in future computers, operations could be performed easier on qubits that retain their quantum state for a very short time, says Ben Murdin, a physicist at the University of Surrey and corresponding author of the paper.

The researchers also reported that they could determine the quantum state of a qubit by measuring the amount of current passing through the silicon. The point of the experiment, says Murdin, is to show that it’s possible to use completely standard commercial silicon, and a simple voltmeter for the readout of quantum superpositions. "It's the first electrical detection of orbital qubits in silicon,” he says. And the only piece of fancy equipment that’s required is the laser.

Murdin notes that electrical readouts of quantum states have advantages for other quantum technologies too. "I don't know how to make a quantum computer, but this method would help enormously if you want an atomic clock or a quantum magnetometer,” the Surrey professor says.

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