Then, this morning, the exclusively solar powered prop plane Solar Impulse (built by the company of the same name) took off on a San Franciso-Phoenix trip, part of a tour of the US for study and fundraising. It's early days, the plane is really lightweight and flies low and slow, but who knows how far they can take this?NBC news wrote:The U.S. Air Force's $300 million, nine-year test program for a hypersonic plane ended on a high note this week, when the last of its X-51A Waverider vehicles made the longest flight of its kind. The success was made sweeter by the fact that it followed last year's high-profile failure.
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"I believe all we have learned from the X-51A Waverider will serve as the bedrock for future hypersonics research and ultimately the practical application of hypersonic flight," Charlie Brink, X-51A program manager for the Air Force Research Laboratory Aerospace Systems Directorate, said in a news release.
The 14-foot-long (4.3-meter-long), scramjet-powered vehicle hit a top speed of Mach 5.1 during just over six minutes of flight on May 1, the Air Force said. That's the longest of the Boeing-built X-51A's four test flights, and the longest air-breathing hypersonic flight ever.
Hypersonic scramjet propulsion has been widely touted as eventually opening up the way for flights between London and New York in less than an hour. But in reality, the first application is more likely to come in the form of super-fast cruise missiles.
Scramjet is a short way of saying "supersonic combustion ramjet." There have been many efforts through the years to perfect hypersonic aircraft — that is, vehicles that travel at speeds beyond Mach 5. But the Air Force says the X-51A is unique primarily because it used hydrocarbon fuel rather than hydrogen fuel. Without any moving parts, the fuel is injected into the scramjet's combustion chamber, where it mixes with the air rushing through the chamber. The fuel is ignited in a process that's been likened to lighting a match in a hurricane.
This week's experiment followed the flight profile used for the X-51A's earlier tests: A B-52H Stratofortress took off from California's Edwards Air Force Base, flew 50,000 feet over a Pacific test range, and then released a solid rocket booster with the plane attached. When the cruiser reached Mach 4.8, the X-51A separated from the booster and lit up its scramjet engine. The scramjet exhausted its fuel in 240 seconds. The sleek vehicle coasted for another couple of minutes and splashed down into the ocean as planned. The X-51 traveled more than 230 nautical miles and yielded 370 seconds of data, the Air Force said.
"This success is the result of a lot of hard work by an incredible team. The contributions of Boeing, Pratt and Whitney Rocketdyne, the 412th Test Wing at Edwards AFB, NASA Dryden and DARPA were all vital," Brink said.
All this is a huge improvement over the previous test, which ended in failure last August. During that flight, the X-51A veered off course less than a minute after launch and crashed, due to a problem with one of its control fins. The issue was resolved after a months-long investigation. The first X-51 test was successful in May 2010, resulting in a 200-second flight, but the second test in June 2011 was a disappointment.
There's no immediate successor to the X-51A, but the Air Force has pledged to continue with hypersonic research. It says the lessons learned during the X-51A program "will pay dividends to the High Speed Strike Weapon program" at the Air Force Research Laboratory.
They're apparently streaming flight footage, but a casual search didn't turn up the link.also NBC wrote:A Swiss-made, solar-powered airplane called Solar Impulse took off Friday on the first leg of an aerial odyssey across America, beginning what's expected to be the slowest flight from San Francisco to Phoenix with nary a drop of fuel.
Adventurer Bertrand Piccard piloted the craft, which has the wingspan of a jumbo jet but the weight of a typical passenger car, from Moffett Field into the Bay Area's skies at 6:12 a.m. ET (9:12 a.m. ET) and headed south toward Arizona.
"Everything looking fine down here," Mission Control told Piccard after takeoff.
The trip is due to take about 19 hours. You could drive that distance in two-thirds that time – but that's not the point.
"A flying laboratory for clean technologies, this prototype is the result of seven years of intense work in the fields of materials science, energy management and man-machine interface," Andre Borschberg, Solar Impulse's co-founder and CEO, said before the flight.
Borschberg and Piccard will be taking turns in the pilot's seat for a months-long series of flights that should end up in New York around the Fourth of July. Each leg of the odyssey will be covered with streaming video, and the project plans to collect thousands of names that will be added to a "Clean Generation" list of supporters carried in the cockpit.
All of Solar Impulse's power comes from its solar cells, which soak up sunlight and store the electrical energy in batteries for when the sun isn't shining. The plane generates as much power as a motor scooter for its four 10-horsepower motors. That's why the carbon-fiber craft has to be so big and light.
The "Across America" mission builds upon Piccard's experience as a record-setting, round-the-world balloonist, and draws upon financial backing from Swiss business concerns. In 2010, Solar Impulse took on on the world's first solar-powered night flight, a 26-hour affair in Switzerland. The next year, it made the first international solar flight, from Switzerland to Belgium to France. And in 2012, it took on the first solar-powered intercontinental flight, from Europe to North Africa.
Over the next couple of months, Solar Impulse is due to fly from Phoenix to Dallas-Fort Worth, then to St. Louis, then Washington, then New York. As ambitious as this odyssey is, it's just a warm-up for the venture's ultimate goal: circumnavigating the world with solar power.
So yeah, I doubt this'll make history books or anything, but it's exciting to see new developments in aviation.
