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Old 06-02-2008, 04:51 AM
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glenc (Glen)
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British jet could reach Aust in under 5 hours

New British jet could reach Aust in under 5 hours
British engineers have unveiled plans for a hypersonic jet which could fly from Europe to Australia in less than five hours. The A2 plane, designed by engineering company Reaction Engines based in Oxfordshire, southern England, could carry 300 passengers at a top speed of almost 6,400 kilometres per hour - five times the speed of sound.
The LAPCAT (Long-Term Advanced Propulsion Concepts and Technologies) project, backed by the European Space Agency, could see the plane operating within 25 years, the firm's boss Alan Bond told the Guardian daily.
"The A2 is designed to leave Brussels international airport, fly quietly and subsonically out into the north Atlantic at mach 0.9 before reaching mach 5 across the North Pole and heading over the Pacific to Australia," he said.
The plane, which at 143 metres long would be about twice the size of the biggest current jets, could fly non-stop for up to 20,000 kilometres.
It operates on liquid hydrogen, which is more ecologically friendly as it gives off water and nitrous oxide instead of carbon emissions.
Passengers would have to put up with having no windows, due to problems with heat produced at high speeds.
Instead, designers may put flat screen televisions where the windows would be, giving the impression of seeing outside.
Fares would be comparable with current first class tickets on standard flights.
The flight time from Brussels to Australia would be four hours and 40 minutes.
See: http://www.abc.net.au/news/stories/2...05/2155305.htm
http://news.smh.com.au/hypersonic-je...0205-1qc4.html

AND

France unveils super-fast train
French President Nicolas Sarkozy has attended the launch of a new high-speed train made by engineering giant Alstom.
The AGV (Automotrice Grande Vitesse) train will travel at up to 360km/h (224mph), powered by motors placed under each carriage, the company says.
The absence of locomotives at either end allows it to carry more passengers.
See: http://news.bbc.co.uk/2/hi/europe/7227807.stm
http://news.smh.com.au/france-unveil...0206-1qd2.html

ALSO

Welcome to the future
Power
But those developments are small change compared to the solar energy solution sparking a new space race on several continents. In November, The Guardian reported that commercial entities in the US, Europe and Japan are competing to launch the first solar receptor satellite tower, a giant energy collector that could, according to the Pentagon's National Space Security Office, satisfy 10% of the US's power needs by 2050 (www.tinyurl.com/2lq8gx).
"Space-based solar power offers a way to break the tyranny of these day-night, summer-winter and weather cycles and provide continuous and predictable power to any location on Earth," the Pentagon report says.
How? By zapping concentrated and uninterrupted sunshine 40,000 kilometres Earthwards in laser or microwave beams to be collected by land-based antenna stations.
The Space Islands Group of California expects to have a prototype in orbit in 2009 delivering a steady 10-25 megawatt beam to where it's needed most - most likely a small town in Europe struggling with the increased demand of several thousand wall-mounted LCD mirror TVs.
http://www.smh.com.au/news/articles/...e#contentSwap1
I hope the laser is on target!

Last edited by glenc; 06-02-2008 at 06:03 AM.
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Old 06-02-2008, 06:35 AM
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Quote:
Originally Posted by glenc View Post
The Space Islands Group of California expects to have a prototype in orbit in 2009 delivering a steady 10-25 megawatt beam to where it's needed most
What is the collector size needed to develop 25 megawatts from solar, and what would be the angular size in a geosynchronous orbit assuming a round profile? Consider that the collector would be at opposition at around midnight, and then consider the magnitude of an Iridium flare. Extrapolate.

I hope that nobodies favourite target for imaging is equatorial!

Edit: 152m diameter for a circular solar array of 18,300 square metres at 1366 watts per square metre to deliver 25 megawatts. Angular size 0.78 arc seconds. That's going to be one bright pin point.

Last edited by citivolus; 06-02-2008 at 06:49 AM.
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Old 06-02-2008, 06:55 AM
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Oh, and efficiencies would work out to around 25% or so, so the array would have to be 4x that size to produce the full 25 megawatts. The pdf linked assumes a 5x15km solar collector grid per satellite, and 24 satellites in the constellation, based on a recent design. Admittedly the collectors are at an angle to reflect light into a central collector, so they likely wouldn't flare like an Iridium, but I'm fairly certain that they would still be of a visible magnitude.
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Old 06-02-2008, 06:57 AM
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Not good for astronomy!
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Old 06-02-2008, 08:37 AM
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The designers have acknowledged it in their risk assessment. Some sites quote a figure for some designs being as bright as a quarter moon, but I can't find a reliable source for that info.

The prototype for the 10MW generator is depicted as returning the beam back along its axis from a reflector panel, towards a collector that is offset via a secondary mirror, basically a big Newtonian telescope. That would definitely get your attention at midnight.
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Old 06-02-2008, 03:33 PM
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Hmmm, I traveled at close to 340km/h on a train thru France... 360 isn't much progress.
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Old 07-02-2008, 12:28 PM
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The current "worlds fastest train", the TGV (Train Grande Vitesse) is capable of travelling at far higher speeds (holding the record of 574.8 kp/h). It just doesn't for safety reasons, and it takes too long to STOP it.
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Old 10-02-2008, 05:27 PM
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Yep, I've seen these sorts of predictions before. Find some old Popular Science mags from a few decades ago and see how many of the predictions they made have actually come true. It's fine to run an aircraft on hydrogen but first you need to make the hydrogen fuel and for that you need power. I don't believe that in the future we'll be able to generate any where near enough power for our most basic needs, let alone frivolous needs such as flying supersonically from Britain to OZ. Predict that in 50 years people will be embarking on fast sailing ships for a lengthy trip to Oz and I reckon you'll be closer to the mark.
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Old 10-02-2008, 05:51 PM
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I'm inclined to agree with acropolite. At the rate our resources are dwindling and the damage being done by our way of life it's more likely there will be a slowing down of travel rather than a speeding up. Looking at the advances in communications over the last 50 years I would reckon that at least 50% of the non holiday air travel is unneccessary. Why fly 2000 miles to present a paper or talk with a customer when it could be done by satellite video link. Answer, one of the perks, get to travel to another city or foriegn country at the companies expense. Time to get back to the old wartime slogan "Is Your Journey Really Neccessary"

Bill
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