Wednesday, August 24, 2011
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Thursday, August 11, 2011
Pentagon's hypersonic flight test cut short by anomaly
Pentagon's hypersonic flight test cut short by anomaly
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: August 11, 2011
A hypersonic glider launched Thursday by the U.S. military was lost in flight, the second straight mishap crippling the Pentagon's desire to develop a strategic weapon to deliver conventional munitions anywhere in the world in less than an hour.
Artist's concept of the Hypersonic Test Vehicle 2 during separation of the Minotaur rocket's payload fairing. Credit: DARPA
After a successful launch aboard a Minotaur 4 rocket, the arrowhead-shaped Hypersonic Test Vehicle 2 separated and transitioned to aerodynamic flight at a speed of Mach 20, according to the Defense Advanced Research Projects Agency, or DARPA.
The military said they collected more than nine minutes of data before an anomaly caused a loss of signal from the hypersonic glider. Ships, aircraft and other tracking assets were in place to receive communications from the high-speed vehicle.
Liftoff occurred at 7:45 a.m. Pacific time (10:45 a.m. EDT; 1445 GMT) from Vandenberg Air Force Base, Calif. It used a three-stage version of the Minotaur 4 rocket, which is powered by retired Peacekeeper missile motors.
The flight should have lasted more than a half-hour before impacting the Pacific Ocean near the U.S. Army's Reagan Test Site at Kwajalein Atoll in the Marshall Islands. Initial indications are the aircraft struck the Pacific Ocean along the planned flight path, according to DARPA.
A nearly identical test vehicle launched in April 2010 also ended prematurely after the craft lost control. Engineers adjusted the second HTV's center of gravity, modifed its angle of attack, and designed it to use thruster jets to help the vehicle control itself.
"We know how to boost the aircraft to near space. We know how to insert the aircraft into atmospheric hypersonic flight," said Air Force Maj. Chris Schulz, DARPA's HTV 2 program manager. "We do not yet know how to achieve the desired control during the aerodynamic phase of flight. It's vexing; I'm confident there is a solution. We have to find it."
After being released from the Minotaur's third stage, the glider was supposed to orient itself for entry back into Earth's atmosphere, then pull up to begin a long-distance glide toward an impact site in the Pacific Ocean.
Thursday's mission, named HTV 2b, was supposed to try out gliding, aerodynamic maneuvers and control algorithms in the hypersonic flight regime at the edge of space.
Artist's concept of the Hypersonic Test Vehicle 2 in aerodynamic flight. Credit: DARPA
Schulz said three major technical challenges exist within the HTV 2 flight envelope, including aerodynamic, aerothermal and guidance, navigation and control. After reaching its peak velocity, temperatures outside the craft's insulated skin were expected to reach 3,500 degrees Fahrenheit.
"Prior to flight, the technical team completed the most sophisticated simulations and extensive wind tunnel tests possible," said Regina Dugan, director of DARPA. "But these ground tests have not yielded the necessary knowledge. Filling the gaps in our understanding of hypersonic flight in this demanding regime requires that we be willing to fly."
In a written statement, Dugan said DARPA will resolve the issues with hypersonic flight and try again.
"To address these obstacles, DARPA has assembled a team of experts that will analyze the flight data collected during today's test flight, expanding our technical understanding of this incredibly harsh flight regime," Schulz said. "As today's flight indicates, high-Mach flight in the atmosphere is virtually uncharted territory."
DARPA said the data reviewed from Thursday's flight will inform policy, acquisition and operational decisions for the future of the Pentagon's Conventional Prompt Global Strike programs. The HTV test program was part of DARPA's Falcon project.
The Defense Department is attempting to develop a conventional global strike weapon to augment the military's nuclear deterrent. It would be able to hit a target anywhere in the world in less than an hour after launching from the United States or a U.S. military base.
The Air Force was planning to launch a Conventional Strike Missile on another Minotaur 4 rocket in 2013. Packed with munitions, the missile would have separated from the booster like the HTV and glided to a precise target more than 4,000 miles downrange in the Pacific Ocean.
Outcome of military's hypersonic test flight unclear
Outcome of military's hypersonic test flight unclear
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: August 11, 2011
A three-stage Minotaur 4 Lite rocket blasted off Thursday from the California coast, accelerating a U.S. military hypersonic glider to blazing speeds on a test flight demonstrating technologies for an unmanned global strike bomber, but officials lost contact with the vehicle and could not confirm the mission's outcome.
Artist's concept of the Hypersonic Test Vehicle 2. Credit: DARPA
The solid-fueled Minotaur 4 Lite rocket launched at 7:45 a.m. Pacific time (10:45 a.m. EDT; 1445 GMT) and rolled on a trajectory west from Vandenberg Air Force Base. It was expected to reach a speed of 13,000 mph in about three minutes.
Launch was delayed from Wednesday by poor weather over the Pacific Ocean.
The three-stage version of the launcher uses retired Peacekeeper missile motors. A fourth stage can be added for orbital launches with satellite payloads.
The Pentagon's second Hypersonic Test Vehicle, a throwaway high-speed aerodynamic testbed, was programmed to separate from the Minotaur rocket a few minutes after liftoff. The vehicle was designed to orient itself to fall back into the atmosphere and execute maneuvers to control its altitude and velocity before falling in the Pacific Ocean near the U.S. Army's Reagan Test Site at Kwajalein Atoll in the Marshall Islands, according to the military.
The HTV project is managed by the Defense Advanced Research Projects Agency, or DARPA, the Defense Department's research and development unit.
Posting updates on DARPA's Twitter account, the agency said they lost the communications signal from the HTV a few minutes after launch.
"Downrange assets did not reacquire tracking or telemetry," one Twitter update said. The vehicle "has an autonomous flight termination capability. More to follow."
A DARPA spokesperson did not respond to questions Thursday afternoon.
The second HTV flight, called HTV 2b, aimed to complete unfinished testing from an initial demonstration in April 2010. During that flight, the arrowhead-shaped aircraft lost control and had to be destroyed by an on-board termination system.
Engineers blamed the mishap on flight control authority limitations as the HTV soared through the edge of space at more than 10,000 mph. Its control flaps were unable to maintain the vehicle's attitude, causing the craft to yaw and roll before it autonomously commanded the termination of the flight, according to DARPA.
Officials adjusted the second HTV's center of gravity, decreased its programmed angle of attack and used the craft's reaction control system thrusters to help out the flaps keep the vehicle under control, DARPA said in a press release.
Despite the abridged flight, last year's test gathered 139 seconds of useful aerodynamic data and verified navigation, communications and control systems.
The taste of data from the shortened first HTV flight was still more than could have been efficiently collected inside wind tunnels on the ground, according to Air Force Maj. Chris Schulz, the HTV 2 program manager.
Wind tunnels are able to simulate long-term hypersonic flight conditions up to velocities around Mach 15. Beyond that, engineers need special wind tunnels called impulse tunnels to capture data milliseconds at a time. It would have required years, tens of millions of dollars and several hundred impulse tunnel tests to replicate data from the April 2010 demo flight.
"And even then, we wouldn't know exactly what to expect based solely on the snapshots provided in ground testing," Schulz said. "Only flight testing reveals the harsh and uncertain reality."
It's unclear how much data was collected on Thursday's mission.
About three minutes after launch, the Minotaur rocket should have accelerated the HTV payload to about 20 times the speed of sound, fast enough to travel from New York to Los Angeles in 12 minutes. Once the glider was released, it was supposed to first prepare to re-enter Earth's atmosphere, then soar through the edge of space with a series of programmed banks to control the craft's speed and trajectory.
Temperatures outside the vehicle were expected to reach 3,500 degrees Fahrenheit during the most extreme part of the flight, hot enough to melt steel. Tracking ships, planes and space assets were positioned to collect data during the flight, and the HTV was covered in sensors to study how the vehicle responds throughout the mission.
At the end of the mission, the HTV was to make a destructive dive into the ocean.
DARPA says the HTV craft featured a high lift-to-drag aerodynamic shape, lightweight thermal protection structures and autonomous guidance, control and flight safety systems. The vehicles were manufactured by Lockheed Martin Corp.
This pair of HTV tests was part of DARPA's Falcon project. An Air Force-led follow-on flight called the Conventional Strike Missile is planned launch on another Minotaur rocket in mid-2013, in which another HTV will be outfitted with a conventional warhead to be directed toward a target downrange.
Thursday's launch was the fourth flight of a Minotaur 4 rocket. Two of the missions hauled satellites into low Earth orbit, in addition to the dual HTV launches.
Another Minotaur 4 launch is scheduled for Sept. 27 from the Kodiak Launch Complex in Alaska. It will orbit the military's TacSat 4 satellite with an experimental UHF communications package.
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: August 11, 2011
A three-stage Minotaur 4 Lite rocket blasted off Thursday from the California coast, accelerating a U.S. military hypersonic glider to blazing speeds on a test flight demonstrating technologies for an unmanned global strike bomber, but officials lost contact with the vehicle and could not confirm the mission's outcome.
Artist's concept of the Hypersonic Test Vehicle 2. Credit: DARPA
The solid-fueled Minotaur 4 Lite rocket launched at 7:45 a.m. Pacific time (10:45 a.m. EDT; 1445 GMT) and rolled on a trajectory west from Vandenberg Air Force Base. It was expected to reach a speed of 13,000 mph in about three minutes.
Launch was delayed from Wednesday by poor weather over the Pacific Ocean.
The three-stage version of the launcher uses retired Peacekeeper missile motors. A fourth stage can be added for orbital launches with satellite payloads.
The Pentagon's second Hypersonic Test Vehicle, a throwaway high-speed aerodynamic testbed, was programmed to separate from the Minotaur rocket a few minutes after liftoff. The vehicle was designed to orient itself to fall back into the atmosphere and execute maneuvers to control its altitude and velocity before falling in the Pacific Ocean near the U.S. Army's Reagan Test Site at Kwajalein Atoll in the Marshall Islands, according to the military.
The HTV project is managed by the Defense Advanced Research Projects Agency, or DARPA, the Defense Department's research and development unit.
Posting updates on DARPA's Twitter account, the agency said they lost the communications signal from the HTV a few minutes after launch.
"Downrange assets did not reacquire tracking or telemetry," one Twitter update said. The vehicle "has an autonomous flight termination capability. More to follow."
A DARPA spokesperson did not respond to questions Thursday afternoon.
The second HTV flight, called HTV 2b, aimed to complete unfinished testing from an initial demonstration in April 2010. During that flight, the arrowhead-shaped aircraft lost control and had to be destroyed by an on-board termination system.
Engineers blamed the mishap on flight control authority limitations as the HTV soared through the edge of space at more than 10,000 mph. Its control flaps were unable to maintain the vehicle's attitude, causing the craft to yaw and roll before it autonomously commanded the termination of the flight, according to DARPA.
Officials adjusted the second HTV's center of gravity, decreased its programmed angle of attack and used the craft's reaction control system thrusters to help out the flaps keep the vehicle under control, DARPA said in a press release.
Despite the abridged flight, last year's test gathered 139 seconds of useful aerodynamic data and verified navigation, communications and control systems.
The taste of data from the shortened first HTV flight was still more than could have been efficiently collected inside wind tunnels on the ground, according to Air Force Maj. Chris Schulz, the HTV 2 program manager.
Wind tunnels are able to simulate long-term hypersonic flight conditions up to velocities around Mach 15. Beyond that, engineers need special wind tunnels called impulse tunnels to capture data milliseconds at a time. It would have required years, tens of millions of dollars and several hundred impulse tunnel tests to replicate data from the April 2010 demo flight.
"And even then, we wouldn't know exactly what to expect based solely on the snapshots provided in ground testing," Schulz said. "Only flight testing reveals the harsh and uncertain reality."
It's unclear how much data was collected on Thursday's mission.
About three minutes after launch, the Minotaur rocket should have accelerated the HTV payload to about 20 times the speed of sound, fast enough to travel from New York to Los Angeles in 12 minutes. Once the glider was released, it was supposed to first prepare to re-enter Earth's atmosphere, then soar through the edge of space with a series of programmed banks to control the craft's speed and trajectory.
Temperatures outside the vehicle were expected to reach 3,500 degrees Fahrenheit during the most extreme part of the flight, hot enough to melt steel. Tracking ships, planes and space assets were positioned to collect data during the flight, and the HTV was covered in sensors to study how the vehicle responds throughout the mission.
At the end of the mission, the HTV was to make a destructive dive into the ocean.
DARPA says the HTV craft featured a high lift-to-drag aerodynamic shape, lightweight thermal protection structures and autonomous guidance, control and flight safety systems. The vehicles were manufactured by Lockheed Martin Corp.
This pair of HTV tests was part of DARPA's Falcon project. An Air Force-led follow-on flight called the Conventional Strike Missile is planned launch on another Minotaur rocket in mid-2013, in which another HTV will be outfitted with a conventional warhead to be directed toward a target downrange.
Thursday's launch was the fourth flight of a Minotaur 4 rocket. Two of the missions hauled satellites into low Earth orbit, in addition to the dual HTV launches.
Another Minotaur 4 launch is scheduled for Sept. 27 from the Kodiak Launch Complex in Alaska. It will orbit the military's TacSat 4 satellite with an experimental UHF communications package.
Wednesday, August 10, 2011
Weather forces delay in launch of global strike demo
Weather forces delay in launch of global strike demo
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: August 10, 2011
Poor weather over the Pacific Ocean forced military officials to put off the planned Wednesday launch of a hypersonic glider from Vandenberg Air Force Base in California.
Photo of the Minotaur 4 Lite rocket before launch. Credit: U.S. Air Force
The mission was scrubbed because of inclement weather conditions downrange west of Vandenberg, the nation's primary West Coast launch site located between San Francisco and Los Angeles.
Bad weather was reported near Kwajalein Atoll, the remote destination for the mission's high-speed flight demonstrator. After conducting maneuvers over the Pacific Ocean, the arrowhead-shaped vehicle is supposed to fall back to Earth near the U.S. Army's Reagan Test Site near Kwajalein in the Marshall Islands.
Liftoff is rescheduled for 7 a.m. Pacific time (10 a.m. EDT; 1400 GMT) Thursday aboard a three-stage Minotaur 4 Lite launch vehicle, according to the U.S. Air Force. The launch could occur from 7 a.m. through 1 p.m. local time.
The mission's goal is to demonstrate hypersonic gliding and maneuvering techniques at the edge of space at speeds eclipsing 13,000 mph. The test flight could help the Pentagon develop a prompt global strike program to deliver conventional warheads to faraway targets in less than an hour.
It is the second flight of the military's Hypersonic Test Vehicle 2, a craft built by Lockheed Martin Corp. for the Defense Advanced Research Projects Agency, or DARPA.
An initial demo flight in April 2010 ended prematurely when the HTV lost control and had to be destroyed. Engineers concluded the anomaly was due to flight control authority limitations when the vehicle's flaps were unable to maintain the HTV's orientation.
Despite the abridged flight, last year's test gathered 139 seconds of useful aerodynamic data and verified navigation, communications and control systems.
The taste of data from the shortened first HTV flight was still more than could have been efficiently collected inside wind tunnels on the ground, according to Air Force Maj. Chris Schulz, the HTV 2 program manager.
Wind tunnels are able to simulate long-term hypersonic flight conditions up to velocities around Mach 15. Beyond that, engineers need special wind tunnels called impulse tunnels to capture data milliseconds at a time. It would have required years, tens of millions of dollars and several hundred impulse tunnel tests to replicate data from the April 2010 demo flight.
Artist's concept of the Hypersonic Test Vehicle 2. Credit: DARPA
"And even then, we wouldn't know exactly what to expect based solely on the snapshots provided in ground testing," Schulz said. "Only flight testing reveals the harsh and uncertain reality."
The second craft has a different center of gravity, it will fly with a reduced angle of attack, and it will use thruster jets to help control itself in flight, according to DARPA, the military's research and development unit.
"DARPA looks forward to conquering more unknowns about long-duration hypersonic missions," said Dave Neyland, director of DARPA's tactical technology office. "We need to increase our technical knowledge to support future hypersonic technology development. We gained valuable data from the first flight, made some adjustments based on the findings of an engineering review board to improve this second flight, and now we're ready to put all of that to the test."
About three minutes after launch, the Minotaur rocket should accelerate the HTV payload to about 20 times the speed of sound, fast enough to travel from New York to Los Angeles in 12 minutes. Once the glider is released, it will first prepare to re-enter Earth's atmosphere, then soar through the edge of space with a series of programmed banks to control the craft's speed and trajectory.
Temperatures outside the vehicle will reach 3,500 degrees Fahrenheit during the most extreme part of the flight, hot enough to melt steel. Tracking ships, planes and space assets will collect data during the flight, and the HTV is covered in sensors to study how the vehicle responds throughout the mission.
At the end of the mission, the HTV will dive into the ocean and will not be recovered.
DARPA says the HTV craft features a high lift-to-drag aerodynamic shape, lightweight thermal protection structures and autonomous guidance, control and flight safety systems.
This pair of HTV tests is part of DARPA's Falcon project. An Air Force-led follow-on flight called the Conventional Strike Missile is planned launch on another Minotaur rocket in mid-2013, in which another HTV will be outfitted with a conventional warhead to be directed toward a target downrange.
BY STEPHEN CLARK
SPACEFLIGHT NOW
Posted: August 10, 2011
Poor weather over the Pacific Ocean forced military officials to put off the planned Wednesday launch of a hypersonic glider from Vandenberg Air Force Base in California.
Photo of the Minotaur 4 Lite rocket before launch. Credit: U.S. Air Force
The mission was scrubbed because of inclement weather conditions downrange west of Vandenberg, the nation's primary West Coast launch site located between San Francisco and Los Angeles.
Bad weather was reported near Kwajalein Atoll, the remote destination for the mission's high-speed flight demonstrator. After conducting maneuvers over the Pacific Ocean, the arrowhead-shaped vehicle is supposed to fall back to Earth near the U.S. Army's Reagan Test Site near Kwajalein in the Marshall Islands.
Liftoff is rescheduled for 7 a.m. Pacific time (10 a.m. EDT; 1400 GMT) Thursday aboard a three-stage Minotaur 4 Lite launch vehicle, according to the U.S. Air Force. The launch could occur from 7 a.m. through 1 p.m. local time.
The mission's goal is to demonstrate hypersonic gliding and maneuvering techniques at the edge of space at speeds eclipsing 13,000 mph. The test flight could help the Pentagon develop a prompt global strike program to deliver conventional warheads to faraway targets in less than an hour.
It is the second flight of the military's Hypersonic Test Vehicle 2, a craft built by Lockheed Martin Corp. for the Defense Advanced Research Projects Agency, or DARPA.
An initial demo flight in April 2010 ended prematurely when the HTV lost control and had to be destroyed. Engineers concluded the anomaly was due to flight control authority limitations when the vehicle's flaps were unable to maintain the HTV's orientation.
Despite the abridged flight, last year's test gathered 139 seconds of useful aerodynamic data and verified navigation, communications and control systems.
The taste of data from the shortened first HTV flight was still more than could have been efficiently collected inside wind tunnels on the ground, according to Air Force Maj. Chris Schulz, the HTV 2 program manager.
Wind tunnels are able to simulate long-term hypersonic flight conditions up to velocities around Mach 15. Beyond that, engineers need special wind tunnels called impulse tunnels to capture data milliseconds at a time. It would have required years, tens of millions of dollars and several hundred impulse tunnel tests to replicate data from the April 2010 demo flight.
Artist's concept of the Hypersonic Test Vehicle 2. Credit: DARPA
"And even then, we wouldn't know exactly what to expect based solely on the snapshots provided in ground testing," Schulz said. "Only flight testing reveals the harsh and uncertain reality."
The second craft has a different center of gravity, it will fly with a reduced angle of attack, and it will use thruster jets to help control itself in flight, according to DARPA, the military's research and development unit.
"DARPA looks forward to conquering more unknowns about long-duration hypersonic missions," said Dave Neyland, director of DARPA's tactical technology office. "We need to increase our technical knowledge to support future hypersonic technology development. We gained valuable data from the first flight, made some adjustments based on the findings of an engineering review board to improve this second flight, and now we're ready to put all of that to the test."
About three minutes after launch, the Minotaur rocket should accelerate the HTV payload to about 20 times the speed of sound, fast enough to travel from New York to Los Angeles in 12 minutes. Once the glider is released, it will first prepare to re-enter Earth's atmosphere, then soar through the edge of space with a series of programmed banks to control the craft's speed and trajectory.
Temperatures outside the vehicle will reach 3,500 degrees Fahrenheit during the most extreme part of the flight, hot enough to melt steel. Tracking ships, planes and space assets will collect data during the flight, and the HTV is covered in sensors to study how the vehicle responds throughout the mission.
At the end of the mission, the HTV will dive into the ocean and will not be recovered.
DARPA says the HTV craft features a high lift-to-drag aerodynamic shape, lightweight thermal protection structures and autonomous guidance, control and flight safety systems.
This pair of HTV tests is part of DARPA's Falcon project. An Air Force-led follow-on flight called the Conventional Strike Missile is planned launch on another Minotaur rocket in mid-2013, in which another HTV will be outfitted with a conventional warhead to be directed toward a target downrange.
| Fox News-Technology - More Headlines |
| Inside the Air Force's 13,000-MPH Hypersonic Plane |
| Wed Aug 10, 2011 09:43 AM EDT |
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