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US and China join fusion project
CHINA and the US are officially joining the largest international science project of the next decade — excepting the International Space Station.
The project is the latest stage in the quest to develop fusion power - the energy source of the Sun and other stars.
Advocates say it could be cheap and environmentally friendly, though very expensive and time-consuming to develop.
Iter, the International Thermonuclear Energy Reactor, will be built over the next 10 years at a cost of about $5bn.
It will bridge the gap between current fusion reactors and the first ever commercial plant that could follow. Delegations from China and the US joined those from Canada, the European Union, Japan and the Russian Federation at the Eighth Iter Negotiations Meeting held in Russia a few days ago.
The US had previously withdrawn from Iter negotiations undertaking a review of its fusion policy. Now, however, the US and China have declared their commitment to develop fusion energy as a potential source of energy.
At the meeting, the Chinese delegation said that, as the largest developing country in the world, it has a great need to pursue alternative energy sources.
Dr Jerome Pamela of Jet (Joint European Torus, a European flagship fusion project based at Culham in Oxfordshire, UK), said: “China is probably the country in the world that has the largest needs for development of electrical power production.”
To use fusion reactions as an energy source, it is necessary to heat a gas to temperatures exceeding 100 million Celsius — many times hotter than the centre of the Sun. At these temperatures, the gas becomes a plasma. Under these conditions, the plasma particles, from deuterium and tritium, fuse to form helium and high speed neutrons, releasing significant amounts of energy.
A commercial power station will use the heat generated by the neutrons, slowed down by a blanket of denser material (lithium), to generate electricity.
The fuels used are virtually inexhaustible. Deuterium and tritium are both isotopes of hydrogen. Deuterium is extracted from water and tritium is manufactured from a light metal, lithium, which is found all over the world.
One kilogram would produce the same amount of energy as 10,000,000 kg of fossil fuel.
Iter would be the world’s largest international cooperative research and development project next to the International Space Station. The goal of Iter is to produce 500 megawatts of fusion power for 500 seconds or longer during each individual fusion experiment and in doing so demonstrate essential technologies for a commercial reactor.
Iter could begin construction in 2006 and be operational in 2014. Fusion research would last for up to 20 years.
Shuttle crew’s last minutes shown
Nasa has aired footage showing some of the final moments from inside the Columbia space shuttle before it disintegrated while heading back to Earth.
The 13 minutes of videotape were recovered from among the debris of the shuttle which was destroyed, killing all its seven astronauts, on Feb 1. The pictures showed four members of the crew on the flight deck going through routine checks and preparations about 30 minutes before a scheduled landing in Florida.
Investigators are trying to find out what caused Columbia to break apart after re-entering the Earth’s atmosphere.
They saw Commander Rick Husband, pilot Willie McCool and specialists Laurel Clark and Kalpana Chawla as the shuttle descended from an altitude of 150,000 metres over the South Pacific to a height of about 76,200 metres over Hawaii.
The other three members of the crew, Michael Anderson, David Brown and Israel’s first astronaut Ilan Ramon, were on another deck and were not visible.
The contents of the tape, which ended four minutes before problems were first noticed on the ground and 11 minutes before contact was lost, would be almost mundane in any other situation.
Chawla discusses putting on her gloves before the astronauts begin to feel the effects of gravity while McCool moves a clock to be out of the way and Husband takes a drink from a pouch of liquid.
Clark, dressed like the others in an orange spacesuit and helmet with raised visor, takes the camera from its fixed position and films herself and Chawla smiling.
But with hindsight, there are dreadfully poignant moments as well.
Clark films the view from the window with many flashes of light, which Nasa says is a normal sight during a night-time re-entry.
McCool, who was on his first shuttle flight, seemed excited by the flares from plasma he could see from the front window.
“Wow,” he said. “This is amazing.”
“It’s really neat, it’s a bright orange-yellow out over the nose, all over the nose,” he added.
He also noticed the beginning of the effects of gravity as the shuttle re-entered Earth’s atmosphere.
“Yep, we’re getting some Gs [gravity] - let go of the card and it falls,” he said.
Husband, on his second mission, described the view for the rest of his crew.
“Looks like a blast furnace,” he said before adding jokingly: “You definitely don’t want to be outside now.”
Clark replies: “What, like we did before?” generating laughter from her crewmates.
The 13 minutes of footage from the flight deck were scrutinised by investigators and deemed to have no value for identifying what happened to the shuttle. — Dawn ScienceDotcom Report
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