x-51 waverider - any live coverage of this today?
Pitts - aside from a few photos out of Edwards of it on the pylon and an emailed statement by one John P. Haire of Edwards Air Force Base - haven't seen anything yet.
Latest news seems to say the BUFF has returned safely to Edwards minus payload.
Updated...
And now we know why.
A pity.
The U.S. Air Force says its most ambitious test of its X-51 WaveRider hypersonic aircraft ended in failure less than a minute after launch on Tuesday, due to a flaw in one of the craft's control fins. The X-51 broke apart after it was dropped from a B-52 bomber, with pieces falling into the Pacific Ocean, a spokesman for the project told me today.
If the test had proceeded as planned, the Boeing-built X-51 would have shot through the sky for a five-minute flight at a speed of up to 3,600 mph (5,800 kilometers per hour), or six times the speed of sound. Instead, the Air Force is going back to the drawing board.
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 term for "supersonic combustion ramjet," and there have been many efforts through the years to perfect scramjet-powered aircraft.)
In a statement, the Air Force said the unmanned craft was successfully launched from the B-52 over Point Mugu Naval Air Warfare Center Sea Range, in the Pacific near California's coast, at about 11:36 a.m. PT (2:36 p.m. ET) on Tuesday. The X-51's rocket booster fired as planned — but 16 seconds later, a fault was identified with the cruiser control fin, the Air Force said. When the X-51 separated from the booster, about 15 seconds later, the cruiser couldn't maintain control and was lost.
"'Came apart' is the term that they used," said Daryl Mayer, a spokesman for the Air Force's 88th Air Base Wing at Wright-Patterson Air Force Base in Ohio.
The WaveRider never had a chance to reach supersonic speed.
"It is unfortunate that a problem with this subsystem caused a termination before we could light the scramjet engine," Charlie Brink, X-51A program manager for the Air Force Research Laboratory, said in today's statement. "All our data showed we had created the right conditions for engine ignition, and we were very hopeful to meet our test objectives."
The Air Force said the control system had proven reliable during the X-51A's two previous flights — including a successful test in May 2010 and a not-so-successful test in June 2011.
Today's statement said program officials will conduct a "rigorous evaluation" of this week's test to assess all the factors behind the failure. One of the four X-51A vehicles remains, but officials have not decided when or if that vehicle will fly, the Air Force said. The X-51 project's cost has been estimated at $140 million.
Latest news seems to say the BUFF has returned safely to Edwards minus payload.
Updated...
And now we know why.
A pity.
The U.S. Air Force says its most ambitious test of its X-51 WaveRider hypersonic aircraft ended in failure less than a minute after launch on Tuesday, due to a flaw in one of the craft's control fins. The X-51 broke apart after it was dropped from a B-52 bomber, with pieces falling into the Pacific Ocean, a spokesman for the project told me today.
If the test had proceeded as planned, the Boeing-built X-51 would have shot through the sky for a five-minute flight at a speed of up to 3,600 mph (5,800 kilometers per hour), or six times the speed of sound. Instead, the Air Force is going back to the drawing board.
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 term for "supersonic combustion ramjet," and there have been many efforts through the years to perfect scramjet-powered aircraft.)
In a statement, the Air Force said the unmanned craft was successfully launched from the B-52 over Point Mugu Naval Air Warfare Center Sea Range, in the Pacific near California's coast, at about 11:36 a.m. PT (2:36 p.m. ET) on Tuesday. The X-51's rocket booster fired as planned — but 16 seconds later, a fault was identified with the cruiser control fin, the Air Force said. When the X-51 separated from the booster, about 15 seconds later, the cruiser couldn't maintain control and was lost.
"'Came apart' is the term that they used," said Daryl Mayer, a spokesman for the Air Force's 88th Air Base Wing at Wright-Patterson Air Force Base in Ohio.
The WaveRider never had a chance to reach supersonic speed.
"It is unfortunate that a problem with this subsystem caused a termination before we could light the scramjet engine," Charlie Brink, X-51A program manager for the Air Force Research Laboratory, said in today's statement. "All our data showed we had created the right conditions for engine ignition, and we were very hopeful to meet our test objectives."
The Air Force said the control system had proven reliable during the X-51A's two previous flights — including a successful test in May 2010 and a not-so-successful test in June 2011.
Today's statement said program officials will conduct a "rigorous evaluation" of this week's test to assess all the factors behind the failure. One of the four X-51A vehicles remains, but officials have not decided when or if that vehicle will fly, the Air Force said. The X-51 project's cost has been estimated at $140 million.
Last edited by tartare; 16th Aug 2012 at 00:53.
2 x 180 deg roll
The 2x 180 roll observed on 2 of the simulation videos could be related to some of the following scenarios (?):
(a) After rocket stage burn-out high up in thin air the near-zero g is leaving LH2 fuel in tanks floating freely, roll manoeuvre centrifugal g facilitates fuel being taken from tank to supersonic combustion chamber; after scramjet ignition roll-on to nominal attitude is required for intake aerodynamics and lift aerodynamics.
(b) First roll manoeuvre facilitates mechanical unlocking of rocket stage after burn-out, second manoeuvre as under (a).
(c) Assuming actual roll manoeuvre timings to be possibly different from shown in videos: in the initial rocketed phase increased-g pull-up trajectory the scramjet intake is required on bottom of vehicle for aerodynamic reasons, in the later rocketed phase negative-g levelling-off trajectory the intake is required on the opposite side, in the scramjet propelled near-level flight trajectory the intake is again required on bottom of vehicle.
(d) Artist´s liberty.
Just guesswork, curious to hear anyone´s other ideas.
JR
(a) After rocket stage burn-out high up in thin air the near-zero g is leaving LH2 fuel in tanks floating freely, roll manoeuvre centrifugal g facilitates fuel being taken from tank to supersonic combustion chamber; after scramjet ignition roll-on to nominal attitude is required for intake aerodynamics and lift aerodynamics.
(b) First roll manoeuvre facilitates mechanical unlocking of rocket stage after burn-out, second manoeuvre as under (a).
(c) Assuming actual roll manoeuvre timings to be possibly different from shown in videos: in the initial rocketed phase increased-g pull-up trajectory the scramjet intake is required on bottom of vehicle for aerodynamic reasons, in the later rocketed phase negative-g levelling-off trajectory the intake is required on the opposite side, in the scramjet propelled near-level flight trajectory the intake is again required on bottom of vehicle.
(d) Artist´s liberty.
Just guesswork, curious to hear anyone´s other ideas.
JR
Last edited by janrein; 22nd Sep 2012 at 06:37. Reason: correcting typos
