This article is from the source 'bbc' and was first published or seen on . It last changed over 40 days ago and won't be checked again for changes.
You can find the current article at its original source at http://www.bbc.co.uk/news/technology-19257769#sa-ns_mchannel=rss&ns_source=PublicRSS20-sa
The article has changed 9 times. There is an RSS feed of changes available.
| Version 0 | Version 1 |
|---|---|
| WaveRider hypersonic jet targets Mach 6 | WaveRider hypersonic jet targets Mach 6 |
| (about 1 hour later) | |
| Hypersonic jet WaveRider is to undergo another test flight above the Pacific Ocean aiming to reach Mach 6. | Hypersonic jet WaveRider is to undergo another test flight above the Pacific Ocean aiming to reach Mach 6. |
| At this speed - more than 4,300mph (6,900km/h) - it could travel from London to New York in about an hour. | |
| WaveRider is one of several projects currently under way to create an aeroplane able to reach much higher speeds than today's jets, after Concorde was decommissioned in 2003. | WaveRider is one of several projects currently under way to create an aeroplane able to reach much higher speeds than today's jets, after Concorde was decommissioned in 2003. |
| During a test in June 2011, WaveRider failed to reach the target speed. | During a test in June 2011, WaveRider failed to reach the target speed. |
| A B-52 bomber will lift the wingless unmanned jet from US Edwards Air Force Base in California to 50,000 feet (15,250m). | A B-52 bomber will lift the wingless unmanned jet from US Edwards Air Force Base in California to 50,000 feet (15,250m). |
| The craft will then be dropped, and after a free fall of about four seconds, its engine is supposed to ignite. | The craft will then be dropped, and after a free fall of about four seconds, its engine is supposed to ignite. |
| X-51A WaveRider should then climb to 70,000ft (21,300m) and eventually reach Mach 6. | X-51A WaveRider should then climb to 70,000ft (21,300m) and eventually reach Mach 6. |
| The Mach number is the ratio of the speed of an object to the speed of sound. Mach 1 is the speed of sound - approximately 768mph, depending on various factors including temperature and altitude. | |
| So Mach 6 is six times the speed of sound. Concorde's cruising speed was Mach 2 - it flew from London to New York in just over three hours. | |
| The WaveRider test flight is expected to last for about five minutes. At the end of it, the aircraft will break into pieces and fall into the Pacific. | The WaveRider test flight is expected to last for about five minutes. At the end of it, the aircraft will break into pieces and fall into the Pacific. |
| The test is essentially a repeat of last summer's attempt, when the hypersonic aircraft reached Mach 5, but the engine failed to attain full power. | The test is essentially a repeat of last summer's attempt, when the hypersonic aircraft reached Mach 5, but the engine failed to attain full power. |
| Concorde's legacy? | Concorde's legacy? |
| European aerospace and defence giant EADS believes that hypersonic passenger flights are likely to appear in the near future. In 2011, EADS presented its own concept of a commercial high-speed aircraft designed to fly at Mach 4. | European aerospace and defence giant EADS believes that hypersonic passenger flights are likely to appear in the near future. In 2011, EADS presented its own concept of a commercial high-speed aircraft designed to fly at Mach 4. |
| "The business community who wanted to be in New York in three hours made Concorde highly viable, and now there's interest on both sides of the Atlantic to jump a generation and go from supersonic flight to hypersonic flight," EADS' vice-president of business development, Peter Robbie, told the BBC. | "The business community who wanted to be in New York in three hours made Concorde highly viable, and now there's interest on both sides of the Atlantic to jump a generation and go from supersonic flight to hypersonic flight," EADS' vice-president of business development, Peter Robbie, told the BBC. |
| "Such an aircraft will be very expensive, of course, because of the enormous amounts of energy that is required to get to such speeds. | "Such an aircraft will be very expensive, of course, because of the enormous amounts of energy that is required to get to such speeds. |
| "But the idea of going from Tokyo to Paris in two-and-a-half hours is very attractive for the business and political community - and I think that by about 2050, there may be a viable commercial aircraft." | "But the idea of going from Tokyo to Paris in two-and-a-half hours is very attractive for the business and political community - and I think that by about 2050, there may be a viable commercial aircraft." |
| In August 2011, US military scientists attempted to get another unmanned hypersonic experimental aircraft to reach Mach 20 - 20 times the speed of sound. | In August 2011, US military scientists attempted to get another unmanned hypersonic experimental aircraft to reach Mach 20 - 20 times the speed of sound. |
| However, they lost contact with the Falcon Hypersonic Test Vehicle 2 (HTV-2) after it had separated from its rocket. | However, they lost contact with the Falcon Hypersonic Test Vehicle 2 (HTV-2) after it had separated from its rocket. |