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Today's nuclear reactors provide clean, efficient and continuous power generation with a lifetime between 30-40 years save for their expensive radioisotope fuels, refueling and maintenance every two years and the amount of radioactive waste produced. A special kind of fission reactor called the traveling wave reactor (TWR) reduces the volume of uranium fuel as well as the need for refueling and maintenance. The TWR actually uses conventional reactor radioactive by-products and converts it to fuel it can use using only a small amount of enriched uranium to start the fission process. This means that the TWR can even use its own waste products and run theoretically for a hundred years or more before refueling! It can provide the energy necessary to power the Goldilocks Mission ships, specially if the space travel duration reaches hundreds of years.
So how does it work? The name “traveling wave” comes from the process used in the reactor itself. Using depleted uranium core (spent nuclear fuel or any other nonfissile material), a “wave” that moves at a rate of about one centimeter per year travels through the core and slowly transforms it into plutonium which can then proceed with nuclear fission. The principle behind the TWR is nuclear transmutation.
Tags: nuclear reactor, space technology
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Some of us are very much familiar with the basic requirement for an exoplanet to be counted as habitable: it must reside in the habitable zone of its star. The star should favorably be in the same class as our sun in the main sequence although studies show that red dwarfs could host them as well. As such, much focus is given to searching and filing a catalogue for these types of stars. Enter the HabCat, or the Catalog of Nearby Habitable Systems, a list of about 17,129 stars made by astronomers Margaret Turnbull and Jill Tarter in 2002.
This list came from a much longer list of stars generated by the Hipparcos mission from 1989 to 1993 which took astronometric observations from 118,000 stars with the results published in 1997. Turnbill and Tarter studied this long list of stars to come up with the HabCat, a list of stars that are believed to possess characteristics suitable for life to inhabit the “goldilocks zone” of its planetary systems. It was further narrowed down to the nearest 5,000 stars closest to us in about a 100 light year distance. Turnbull moved on further to identify ten stars in 2006 that have a better likelihood of hosting habitable planets.
Tags: habitable, star, exoplanet
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Almost nine months after Kepler space telescope launched to space, scientists reveal the first five extrasolar planets discoveries that hopes to inspire us that habitable exoplanets are indeed on the way. Although these exoplanets were not really the type that Kepler was created for to detect, the success of finding them proves that scientists are finally on the verge of nailing the first habitable exoplanet.
Kepler, the so called planet-hunter, was launched in March 7, 2009 after several delays due to NASA budget cuts. Its mission is to find any earth-size exoplanet that lie within the habitable zone of stars, the well-known Goldilocks planet. Unlike the Hubble space telescope, Kepler's gears were fine tuned to detect smaller planets and possess a wider field of view for detecting planetary transits, an event where an exoplanet passes in front of its star. Kepler, however, has the opportunity to observe it a couple of times more than Hubble. In this way it observes the the degree of reduction of brightness of the star from whence the diameter of the exoplanet is derived.
Tags: habitable, star, exoplanet
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Ever since scientists discovered the incredulous tensile strength of carbon nanotubes and its unique properties, the wonder material has found numerous applications in various technologies but has yet to fulfill its part in what made it famous the first time, the space elevator. Much research has been done in the last two decades and still continuing, for carbon nanotubes (CNT) do hold a lot of promise in its home niche, nanoscience and nanotechnology. It may seem a bit ironic then for it to be the main component to what may be the world's gigantic superstructure, one that pierces through the stratosphere and even go beyond where most satellites orbit the earth. For all its worth, carbon nanotubes are still the best uncontested theoretical candidates for constructing the space elevator cable.
It's been called a lot of things like the “ribbon” and “tether” but the basic design lies on the simple fact that the cable must be strong enough to support its own weight and withstand tensile forces that would break and shatter even the strongest steel. To illustrate that fact, a carbon nanotube “ribbon” which weighs a sixth that of steel of the same dimension is significantly stronger one hundred times over. This property is in itself a perfect testament to the material's incredible attributes which make it a fitting component in the space elevator cable.
Tags: space elevator, carbon nanotubes, Updates, space technology
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News spread recently about a super-earth sized planet that has been recently discovered to contain one of the most essential compounds for life to exist in the universe, water. With a mass of approximately five to ten times that of earth, GJ 1214b is one of the three exoplanets to have been detected and classified as a super earth by MEarth, a group of astronomers searching for earthlike planets. Most extrasolar planets that have been discovered in the past were huge and hot Jupiter-like gas giants while some were seen as frozen inhospitable planets.
GJ1214b, a massive planet that can house about six earths, orbits a red dwarf at a distance of 1/40th the span between Mercury and our sun and is about forty light years away from us. While some would dismiss the findings and wave off GJ1214b because of the abnormally close orbit with its parent star, we see a different picture and we are inclined to agree with what the scientists have to say. First, the star is a red dwarf, and is significantly more than three hundred times less luminous than our own. Second, scientists believe that its thick atmosphere allows liquid water to exist due to the pressure exerted on the planet’s surface. Third, the observations and smart conjectures are convincing enough such that the presence of water itself on the planet immediately opens up a million of possibilities. Wasn’t there a saying back in school that says “water is a universal solvent”? We use water in our everyday lives and of course, our bodies are mostly made up of water. There is apparently no reason why humans cannot survive there.
Tags: habitable, star, exoplanet
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