Airborne laser to shoot ballistic missile as part of flight test

September 12, 2009 By Leave a Comment

London, September 12 (ANI): Soon, the Airborne Laser (ABL), built into a customized Boeing 747, is ready for flight tests, in which it will try to shoot a ballistic missile.

According to a report in New Scientist, the US Department of Defense’s Missile Defense Agency (MDA) has developed the ABL.

The ABL aims to focus a beam of laser energy in the megawatt range for several seconds onto a missile at a “militarily significant distance” – more than 100 kilometres.

So far, the laser has only operated at near full power on the ground. On August 18, it was fired successfully from the air, but at reduced power.

That, however, was no mean feat, as aircraft vibrations play havoc with the precisely aligned optical components needed to generate a laser beam.

Firing at full power poses other challenges as well.

At powers high enough to destroy missiles, any surface contamination or tiny flaw in the laser optics can absorb so much heat that they crack or shatter.

High-power laser beams also heat the air they pass through, creating perturbations that can disperse or divert the beam.

To counteract those effects, the ABL uses an adaptive system that senses atmospheric changes along its path and makes optical adjustments to compensate.

To test that system, the MDA plans a series of increasingly powerful shots at modified ballistic missiles loaded with sensors to measure the distribution of laser power on the target.

Engineers will assess each shot’s performance and use the results to fine-tune the adaptive optics.

Once this is done, the MDA will test the laser again in varying conditions, and attempt to destroy actual missiles.

The first of these tests is planned to take place late this year, with two more to follow in early 2010, according to an MDA spokeswoman. (ANI)

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NASA tests largest rocket parachutes ever for Ares I rocket

May 21, 2009 By Leave a Comment

Washington, May 21 (ANI): NASA and industry engineers successfully completed the first test of the Ares I rocket’s three main parachutes on May 21, which are the largest rocket parachutes ever manufactured.

The parachutes are designed to slow the rapid descent of the rocket’s spent first-stage motor, permitting its recovery for use on future flights.

The Ares I, the first rocket in NASA’s Constellation Program, is designed to launch explorers aboard the Orion crew capsule on journeys to the International Space Station, the moon and beyond.

The three main parachutes measure 150 feet in diameter and weigh 2,000 pounds each.

They are a primary element of the rocket’s deceleration system, which also includes a pilot parachute and drogue parachute.

Deployed in a cluster, the main parachutes open at the same time, providing the drag necessary to slow the descent of the huge solid rocket motor to a soft landing in the ocean.

“The successful main chute cluster test today confirms the development and design changes we have implemented for the Ares I first stage recovery system,” said Ron King, Ares I first stage deceleration subsystem manager for the Ares Projects at NASA’s Marshall Space Flight Center in Huntsville, Alabama.

“Thanks to our great, collaborative team, the test went as anticipated, and all of our design objectives were met,” he added.

Engineers from Marshall managed the team that conducted this first cluster test at the U.S. Army’s Yuma Proving Ground near Yuma, Arizona.

This was the eighth in an ongoing series of flight tests supporting development of the Ares I recovery system.

Researchers dropped the 41,500-pound load from a U.S. Air Force C-17 aircraft flying at an altitude of 10,000 feet. The parachutes and all test hardware functioned properly and landed safely.

As the test series progresses, engineers will perform three classifications of testing: development, design load and overload.

Each level of testing is designed to fully test the performance of the new parachute design with different size payloads under varying conditions.

The next test in the cycle, scheduled for fall 2009, will involve the first design limit load test of a single main parachute. (ANI)

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NASA plans to reduce sonic booms to distant rumbles in jets

February 11, 2009 By Leave a Comment

London, Feb 11 (ANI): If NASA has its way, the sonic booms coming out of jets might be reduced to distant rumbles.

According to a report in New Scientist, quieter supersonic aircraft might soon become a reality, with NASA completing a delicate set of flight tests to measure how modifications to an F-15 jet can affect the way shock waves form.

The results could help turn sonic booms into distant rumbles.

The measurements will be used to calibrate a computer model of shock wave propagation which will be a crucial aid for engineers designing a new generation of quieter supersonic aircraft.

“We’re pretty close to being able to control sonic booms,” said Peter Coen of NASA’s Langley Research Center in Virginia, principal investigator for the agency’s supersonic research programme.

Shock waves form at the front and back of supersonic aircraft as they shove air out of the way. When these shock waves hit the ground, observers hear them as a single boom.

Public opposition to booms has led to a ban on civilian supersonic flight over US land, and this key factor has discouraged further development of supersonic planes.

Attempts to quieten the sound have focused on a technique called boom shaping, which has it that booms would be weaker if they spread out over a larger area.

The idea is to redesign the shock-forming zones around the nose and tail so that waves from them don’t hit the ground together, but instead arrive over a longer period, like distant thunder.

Five years ago, NASA, the US Defense Advanced Research Projects Agency and several aerospace companies studied how a spiked nose-cone fitted to an F-5 fighter jet affected shock waves generated at the nose.

Now, NASA has finished a similar set of measurements of the boom generated at the rear of an aircraft. This depends on the shape of the wings and air flow around the engine.

The “Lift and Nozzle Change Effects Tail Shock” project (LANCETS) measured the shock waves produced by a modified F-15 jet in different wing and engine configurations.

The measurements were taken by a second F-15 flying close behind and will be used to calibrate NASA’s computer models of how shock waves form.

If the results live up to expectations, the next step would be to modify a jet so that it produces a low rumble rather than a boom in supersonic flight.

“We think we could do it in the next four to five years,” Coen told New Scientist. (ANI)

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NASA instrument aboard Chandrayaan has a peek inside Moon’s darkest craters

January 17, 2009 By Leave a Comment

Washington, Jan 17 (ANI): Scientists are using a NASA radar flying aboard India’s Chandrayaan-1 spacecraft to get their first look inside the moon’s coldest and darkest craters.

The Mini-SAR instrument, a lightweight, synthetic aperture radar, has passed its initial in-flight tests and sent back its first data.

The images show the floors of permanently-shadowed polar craters on the moon that aren’t visible from Earth.

Scientists are using the instrument to map and search the insides of the craters for water ice.

“The only way to explore such areas is to use an orbital imaging radar such as Mini-SAR,” said Benjamin Bussey, deputy principal investigator for Mini-SAR, from the Johns Hopkins University Applied Physics Laboratory in the US.

“This is an exciting first step for the team which has worked diligently for more than three years to get to this point,” he added.

The images, taken on November 17, 2008, cover part of the Haworth crater at the moon’s south pole and the western rim of Seares crater, an impact feature near the North Pole.

Bright areas in each image represent either surface roughness or slopes pointing toward the spacecraft.

Further data collection by Mini-SAR and analysis will help scientists to determine if buried ice deposits exist in the permanently shadowed craters near the moon’s poles.

“During the next few months, we expect to have a fully calibrated and operational instrument collecting valuable science data at the moon,” said Jason Crusan, program executive for the Mini-RF Program for NASA’s Space Operations Mission Directorate in Washington.

Mini-SAR is one of 11 instruments on the Indian Space Research Organization’s Chandrayaan-1 and one of two NASA-sponsored contributions to its international payload.

The other is the Moon Mineralogy Mapper, a state-of-the-art imaging spectrometer that will provide the first map of the entire lunar surface at high spatial and spectral resolution.

Data from the two NASA instruments will contribute to the agency’s increased understanding of the lunar environment.

Chandrayaan-1 was launched from India’s Satish Dhawan Space Center on October 21 and began orbiting the moon November 8. (ANI)

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