You are browsing the archives of 2009 July.

Credit: Lockheed Martin

NASA’s next Mars rover’s massive heat shield is finally ready for the robot. It is the largest heat shield ever built for a spacecraft destined for the red planet. The extra size is needed because this rover - dubbed Curiosity – is about the size of a small car and could endure temperatures up to 3,800 degrees F when it enters the Martian atmosphere.

The thermal protection system is a combination of reinforced carbon-carbon on the wing leading edge, thermal blankets on the fuselage and thermal protective ceramic tiles covering the underside of the vehicle and its nose cap. Curiosity’s heat shield is a large aero shell is made of a material called phenolic impregnated carbon ablator, developed at NASA Ames Research Center

The heat shield was manufactured by Lockheed Martin and is claimed to be the largest unit of its kind ever built. It’s 4.5 meters wide, including the back shell. That is a dimension larger than the heat shields for the Apollo spacecraft (under 4 meters) and the ones used for the current Mars rovers, Spirit and Opportunity (2.6 meters).

Uniquely, once Curiosity’s vehicle enters the Martian atmosphere, parachutes will first deploy to slow its descent, and it will jettison its heat shield. Then, using thrusters, part of the vehicle becames a “floating crane” that use a cable system to gently lower Curiousity to the surface of Mars. Confused? Watch this brief animation of how the rover will land and all will be clear.

Curiosity (formally known as the Mars Science Laboratory) is scheduled to launch in the fall of 2011. Its mission is to gather scientific data to help determine whether there is or was life on Mars.

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Geothermal power production gets a boost with nanotechnology. Credit: Johann KR/FLICKR

Earth’s molten mantle is a potentially inexhaustible source of energy that could meet 10 percent of the nation’s energy needs, but cost and safety concerns have hampered the growth of geothermal energy. Last week, Scientific American reported that researchers at the Pacific Northwest National Lab have announced plans to test a more efficient way to tap into safer, low-temperature geothermal stores through cagelike nanostructures.

One of PNNL's metal-organic heat carrying nanostructures

Obama has promoted geothermal energy as a component for kicking the nation’s fossil fuel habit and reducing greenhouse gas emissions. Last week, the Bureau of Land Management auctioned geothermal energy rights on nearly 1,000 square kilometers of public land in the Southwest and expects 111 new geothermal plants by 2015.

These traditional geothermal power plants - which currently account for just 0.5 percent of the nation’s energy supply - tap into hot springs miles beneath Earth’s surface that contain water superheated to between 150°C and 370°C. These springs arise when magma from the outer mantle, about 50 kilometers beneath the surface, intrudes into the crust, heating rock and water. At most power plants, as this high-pressure water is extracted from the reservoir, it expands and turns to steam, powering the plant’s generator turbines.

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Last August, the ACerS Bulletin published a story on the rising costs and unavailability of bauxite. Bauxite, the major source for the production of aluminum, is in high demand in developing countries, and China has staked its claim on the market.

Industrial Minerals reported that U.S. refractories producer Resco Products has refiled an amended proposed class action suit against Chinese producers and traders of refractory grade bauxite, naming Bosai Minerals Group and CMP Tianjin as the defendants.

Resco, which contends that the bauxite price fixing has existed since Jan. 1, 2003, was given the option to refile an amendment after the company’s first case, filed in 2006, was dropped this spring by the U.S. District Court of Pennsylvania for insufficient evidence.

In the amendment, Resco accuses Bosai and CMP (plus several other China-based bauxite producers) of conspiring to fix prices and control the supply of refractory bauxite to the U.S. and elsewhere, stating that, “the defendants have established an illegal cartel that is ongoing today.”

Of significance, particularly to refractory manufacturers requiring bauxite as raw material feedstock, is that there are only two main sources of refractory grade bauxite – China and Guyana – and the latter is operated by Bosai.

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Credit: National Renewable Energy Lab

A new report released by the World Resources Institute claims that an enormous solar energy resource remains largely untapped in the Southwest U.S. That’s hardly news. But interestingly enough, the WRI offers Congress ways to tap into this abundant resource.

It should be noted that WRI’s report focuses, without explanation, solely on one form of concentrating solar power: concentrating solar thermal. It’s unclear if WRI believes CST to be superior to other forms of CSP. Most of the institute’s recommendations and commentary could apply to CSP approaches, but, for the record, they refer only to CST. Here is WRI’s honey-do list for Congress:

• Enact a price on carbon. CST currently is more expensive than coal and other fossil fuel sources. Because CST is a low-carbon technology, enacting a carbon price would help the technology compete with conventional sources. Cap-and-trade is one mechanism for developing a carbon price.
• Fund RD&D. Research, development and demonstration support will facilitate cost reductions of materials and systems, including thermal energy storage, which can bring down costs to make CST competitive with conventional sources of baseload power.
• Create a national Renewable Energy Standard. Currently, some states with RES have a solar “carve out,” or a percentage set aside that must come specifically from solar. These policies have accelerated deployment of CST in those states and increased utility confidence in the technology. A national RES, including a mandate for solar, would send a market signal to invest in renewables such as CST.
• Push for CST in international technology partnerships. China, India and countries in the Middle East and North Africa have great potential for CST. As a promising option to reduce green house gas emissions and improve energy security, CST should be a priority in international collaboration on RD&D issues. For instance, the World Bank’s Clean Technology Fund includes a program dedicated to deploying concentrating solar thermal power.
• Improve the grid and transmission system. Greater federal oversight of the electricity grid and/or improved coordination between grid operators will help bring CST power from the country’s prime CST areas, the Southwest to a broader area.
• Consider alternative investment incentives. While tax credits are important, they are subject to periodic and uncertain renewal, which presents a challenge to investors. Moreover, in the current economy, tax-based incentives may not be as accessible to project developers as they have been in the past. Incentives such as feed-in tariffs, widely used in Europe, require utilities to pay renewable energy generators a fixed, above-wholesale price for the power they produce. Thus, feed-in tariffs directly raise the price paid for renewable generation and guarantees it a buyer over a period of time – a more stable signal to investors.

Sounds easy enough. Get on it, Congress.

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Since everyone has warm, nostalgic feelings for NASA and its technology this week, here’s the latest in aerogel doodads:

Toasty Feet insoles provide a thermal barrier between your feet and the ground by using the nonporous insulating material - aerogel. This nanotechnology, developed for and used by NASA, is the lightest and lowest-density solid known to exist. Aerogel has the highest thermal insulation value of any solid material available today, allowing it to block both heat and cold efficiently, while remaining light and thin enough to fit comfortably in almost any shoe or boot. Without this protection, your feet will become the temperature of the ground on which you stand. With aerogel-infused insoles, your foot temperature will remain constantly comfortable, avoiding the heat loss and gain you would otherwise experience.

Aerogel-infused?!?!? Oh well - I still smell stocking-stuffers!

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