Japan's Brainy Epsilon Rocket Launching on 1st Test Flight Tuesday

Japan's first Epsilon rocket launch carrying the SPRINT-A satellite was canceled Tuesday, Aug. 27, due to an unspecified glitch. Read the full story here: Japan Cancels 1st Launch of Next-Generation Epsilon Rocket

Japan has an extra-smart rocket cued up at the launch pad for a ride into space.

The country's space agency plans to fire its first unmanned Epsilon rocket into orbit on Tuesday (Aug. 27) to demonstrate it is possible for a rocket to do its own health checks using artificial intelligence

                          This process will allow the Japanese Exploration Agency's (JAXA) launch control to proceed on conventional desktop computers rather than the computing behemoths that launch engineers are used to. [See More Photos of Japan's Epsilon Rocket]

You can watch the Epsilon rocket launch live online via JAXA webcast streams.

Japan's Epsilon rocket, due to make its first test flight Aug. 27, 2013, is equipped with artificial intelligence to perform its own health checks before and during launch.
Credit: JAXA

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"This became possible by introducing an automatic and autonomous checking system and reducing hazardous operations as much as possible so that dramatic electricity and manpower savings have been achieved," Yasuhiro Morita, Epsilon's launch vehicle project manager, said in a statement.

He also vaguely hinted at taking even less time to launch rockets: "We still have some room to additionally decrease the campaign period significantly with further improvements," Morita said.

Checking its own health

Japan has been launching solid-fuel rockets since 1955, first into the upper atmosphere and eventually reaching for space. In the ensuing decades, the ground for launch services has greatly shifted.

Miniaturization and more powerful computers are allowing for smaller and smaller satellites. This makes rocket launches cheaper, since there is less mass to bring into orbit, requiring less fuel. Launch costs are still a major drag on satellite budgets, however. That's where JAXA hopes Epsilon will shine.

Epsilon is a three-stage solid-fuel rocket that builds on existing Japanese rocket technology: an H-IIA solid rocket booster in the first stage, and two upper stages based on those used in the discontinued M-V launch vehicle.

Unlike previous upper stages, however, Epsilon will be able to run many of its own status checks, which will save a lot of time and effort for the people normally required to monitor a rocket's health, JAXA officials said.

Japan's Epsilon rocket, due to make its first test flight Aug. 27, 2013, is equipped with artificial intelligence to perform its own health checks before and during launch.
Credit: JAXA

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"You may doubt that artificial intelligence can be used in a rocket, but nowadays a self-inspection function is something commonly seen in machinery," Morito stated. "Another example is a medical device such as the electrocardiograph, which uses artificial intelligence to diagnose heart abnormalities."

Rapid launch time

While Epsilon itself will have extra smarts, JAXA is also aiming to get the rocket off the pad faster than a conventional one. Rocket assembly will be streamlined so that Epsilon can be taken to the pad with most major components put together, rather than doing it on site.

Once the first stage arrives at the launch site, the rest of the rocket can be put together in just seven days, JAXA said. This makes it among the most quickly constructed rockets in the world, JAXA said, and represents a marked improvement over M-V's construction time of 42 days.

Japan's Epsilon rocket, due to make its first test flight Aug. 27, 2013, is equipped with artificial intelligence to perform its own health checks before and during launch.
Credit: JAXA

View full size image

JAXA is also trying to push down the weight of the rocket even further, through methods such as selecting a tougher carbon fiber for the propellant case. The newer case weighs less than previous versions, cutting down on the need for fuel.

Epsilon's first flight is expected to cost $38.5 million (3.8 billion yen) – almost half the $76 million (7.5 billion yen) cost for M-V, JAXA officials stated.

Epsilon won't ride into orbit alone. On board will be a small science satellite, the Spectroscopic Planet Observatory for Recognition of Interaction of Atmosphere (SPRINT-A).

The tiny telescope aims to peer at Venus, Mars and Jupiter and other planets to see how quickly their atmospheres bleed into outer space. With that data in hand, scientists hope to better understand how Earth's atmosphere behaved when our planet was young.

Follow Elizabeth Howell @howellspace, or SPACE.com @Spacedotcom. We're also on Facebook and Google+. Original article on SPACE.com.

Nanodiamond thermometer can find the temperature inside a single living cell

The mercury-in-glass thermometer has served us well for the past 270 years, but sometimes you need something smaller — say to find the temperature inside a single living cell. Researchers at Harvard have discovered a new technique using lasers and diamond nanocrystals to measure temperatures of microscopic structures, recording temperature fluctuations as small as 0.05 Kelvin (0.09ºF) in size.

The technique relies on the quantum properties of the diamonds’ tasty centers. In a diamond crystals with a nitrogen vacancy in its center — a kind of defect — the center's electronic spin comes to depend on its temperature. Laser light bouncing out of one of these nanodiamonds shows up as a different color depending on the center's temperature. And using diamonds also adds some other benefits. Because they're highly chemically inert, changes in the surrounding chemistry don’t affect the outcome, and the method can be used over a broad range of temperatures, for the same reason. In one series of experiments (pictured above), the team implanted a human cell with a gold nanoparticle, used a laser to heat it up (thereby heating up the surrounding cell), and bounced a laser off a diamond implanted in the same cell to record the temperature difference. The results will be published in the August issue of Nature.

So why would you want to know the temperature inside a living cell? The team believes that the gold heating trick, precisely monitored with its diamond-and-laser nanothermometer, could make it possible to "engineer biological processes at the subcellular level," possibly helping to screen for cancer, or cooking the perfect steak, one cell at a time.

TECHNOLOGY UPDATE

Jul 26, 2013

Strained WS₂ nanosheets boost hydrogen production

Atomically thin nanosheets of tungstenite make efficient catalysts for use in the so-called hydrogen evolution reaction. So say researchers at Rutgers University in the US, who have studied a new crystal structure of WS₂ that they obtained by chemical exfoliation. The material could be a good replacement for the expensive platinum-based catalysts currently being employed to produce hydrogen fuel in polymer electrolyte membrane cells.

Chemically exfoliated WS₂

Hydrogen could be an environmentally friendly alternative to conventional fossil fuels, particularly if it is electrochemically produced from ordinary seawater in the so-called hydrogen evolution reaction (HER), for example in polymer electrolyte membrane cells (PEMCs). However, before this can happen, scientists need to make advanced catalysts that decrease the overpotential of HER. The catalysts also need to be inexpensive, which is not the case for Pt – the most electroactive catalyst for hydrogen fuel cells known today

A group of chemical compounds called dichalcogenides could come into their own here. These easily processed materials, which have the chemical formula MX₂, where M is a transition metal (such as Mo or W) and X is S, Se and Te, go from being indirect bandgap semiconductors in the bulk to direct bandgap semiconductors when scaled down to monolayers. This property could make them ideal in a variety of optoelectronics device applications such as light-emitting diodes and solar cells.

Good catalyst for the HER

A team led by Manish Chhowalla has now found that a new crystal structure of WS₂ is a good catalyst for the HER. This structure, known as the 1T phase (which is metallic), has an octahedral geometry and has never been studied before. Researchers previously only looked at the so-called (semiconducting) 2H phase, which has a trigonal prismatic geometry.

A monolayer of WS₂ is very similar in structure to that of grapheme, except that the unit layer is composed of one tungsten atom sandwiched between two layers of sulphur atoms via ionic bonds. As a consequence, a monolayer of WS₂ is three atoms thick, as opposed to one-atom thick graphene (which is made up entirely of carbon atoms). Whether or not the unit layer is 1T or 2H depends on the coordination of the W atoms.

Chhowalla and colleagues were able to obtain the 1T phase by chemically exfoliating (or shaving off) layers of WS₂. Graphene can be produced in this way too. The process induces a phase transition between the 2H and 1T phases.

Producing hydrogen with very low overpotential

Electron microscopy images of the materials reveal that the basal planes of the exfoliated WS₂ nanosheets are not only composed of the 1T phase but that this phase is highly strained too, explained team member Damien Voiry. "Some bonds are under tensile strain, while some are under compression forming a zigzag pattern," he said. "In our experiments, we found that the as-exfoliated WS₂ can be used to produce hydrogen with very low overpotential."

The overpotential is the difference between the thermodynamic potential and the potential at which a reaction occurs at the surface of a given material. In other words, it is the extra energy that needs to be supplied to the system to induce the reaction.

The researchers also found that the energy of hydrogen absorbed on the 1T phase depends on the applied strain and that a positive strain significantly reduces the absorption energy. Indeed, calculations by the team predict that an ideal strain of 2.7% would lead to the most hydrogen being absorbed on the WS₂ nanosheets. And that is not all: another advantage of this 1T phase is that it improves the kinetics of the HER reaction thanks to the fact that is it highly conducting (because it is metallic).

Engineering strain and structure

"Our work points to new ways in which the catalytic activity of TMDs might be improved by simply engineering the strain and structure of these materials," Voiry told nanotechweb.org. "The attraction of working with these exfoliated materials is that they are very efficient, even though they are single layer. Only a small amount of material is thus needed to cover a large surface – a non-negligible advantage compared to platinum."

The 1T phase of chemically exfoliated WS₂ is also highly conductive, so we can imagine developing conducting electrodes made of this material with a very high surface area to increase the density of the catalytic active sites, he added. These electrodes could be then used in PEMCs connected to a solar cell, for example.

Although calculations show that the optimal strain is 2.7% for hydrogen absorption, the material produced by Chhowalla's team is not uniform, with some regions under compression and therefore not active. To overcome this problem, the researchers say that they now plan to work on further increasing the strain in the basal planes of the nanosheets and to increase the ratio of the 1T phase in the exfoliated materials. "We also envisage combining WS₂ with other conductive materials such as graphene or carbon nanotubes to improve the kinetics of the HER reaction, with faster electron transport to the catalytic active sites," said Voiry.

The present research is described in Nature Materials.

E-skin lights up when touched

Researchers at the University of California at Berkeley have succeeded in integrating three distinct electronic components – a semiconducting carbon-nanotube transistor, a pressure-sensitive polymer sensor and an organic light-emitting diode (OLED) array – over large areas on a single plastic substrate. The resulting mechanically flexible sensor network, or "electronic skin", responds to a finger touch by immediately lighting up and the harder it is touched, the brighter the light that is emitted. The technology could help enhance the sense of touch in robots of the future and even find use in applications such as touchscreen wallpapers. Medical applications, such as "e-bandages" that monitor a patient's health in real time, may also be possible.

Fully fabricated interactive e-skin

The team, led by Ali Javey, made the new e-skin by first spin coating a polymer sheet just 25 microns thick on top of a silicon-wafer substrate and subsequently hardening the plastic by baking it in an oven at 300 °C. The electronic components were then vertically built on top of the plastic surface using conventional microfabrication processes. Once the electronics were stacked, the plastic backing layer was peeled away leaving a free-standing film with the sensor network embedded in it.

Each pixel in the active matrix of the device contains a nanotube transistor with its drain electrode connected to the anode of an OLED. A pressure-sensitive polymer is laminated on top of the OLED and it is in electrical contact with the cathode of the OLED at each pixel. The top surface of the polymer is made conducting by coating it with silver ink and acts as the ground contact. When the device is touched, current flows through the polymer layer and switches the OLED on.

Turning on pixels

"Our e-skin is the first flexible system that responds to pressure stimuli of varying intensities and provides a real-time response by emitting light through the integrated OLED display," team member Chuan Wang told nanotechweb.org. "In the system, OLEDs are turned on only where the surface is touched and the intensity of the emitted light depends on the amount of pressure applied. This basically allows us to visualize the applied pressure."

The e-skin can be laminated on a variety of surfaces, curved or otherwise, he added. Potential applications include robot skin, interactive wallpaper and interactive in-vehicle dashboards. "I can also imagine things like e-bandages applied to a person's arm that would continuously monitor blood pressure and pulse rates, for example, while providing real-time feedback."

Interactive e-skin device

The Berkeley team is now busy integrating more functionalities, such as thermal and light sensing, as well as just pressure sensing into its e-skin system. "We are also experimenting with the possibility of having the whole system built using roll-to-roll printing processes for large-scale, low-cost fabrication of the sensor networks, revealed Wang.

The present work is detailed in Nature Materialsdoi:10.1038/nmat3711

Further reading

Spray process applies silver nanowire network to plastic, glass and fabric (Jun 2011)
Hydrogel electronics makes its debut (Jun 2012)
Hairy solution to making sensitive artificial skin (August 2012)
Semiconducting CNT networks make bendy circuits (Mar 2012)

About the author

Belle Dumé is a contributing editor to nanotechweb.org.