2003 TECHNOLOGY VIDEOTAPES |
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Tape Title | Record ID | Date Produced | TRT: |
Synopsis |
| NASA TAKES THE FAMILY CAR OUT FOR A SPIN | G03-002 | 04/18/03 | 00:00:00 | Space flight and advanced aeronautics require specialized engineering expertise and test equipment. Throughout its storied history NASA has acquired both. Yet as a civilian agency, NASA's mandate ultimately is to serve the public. When the National Highway Traffic Safety Administration wanted to test a particular characteristic of ordinary consumer cars and sport utility vehicles, it turned to NASA for the hardware and know-how to get the job done. By using a remarkable one-of-a-kind machine, the two agencies have begun a collaborative series of experiments that could help keep your family wheels turning safely.
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TAPE CONTENTS: |
| ITEM (1): Wheels in a Wheel -- Reporter Package
- Engineering is the discipline you employ when confronted with a mechanical challenge. So when the National Highway and Traffic Safety Administration wanted to develop a new way to test cars and sport utility vehicles, they came to the one federal agency with a stellar reputation for working out engineering details to test vehicles in extreme conditions. They came to NASA.
SOT (Mattiello) re: space agency being right for the job
This is NASA's High Capacity Centrifuge. Initially built during the golden age of the space program to test the stress limits of spacecraft during launch, this one-of-a-kind machine still inspiresŠand performsŠlike nothing else. That's why the space agency has joined forces with experts at NHTSA. By spinning ordinary cars, trucks, and sport utility vehicles in place of satellites, engineers hope to collect information that could help prevent rollovers.
SOT (Kratzke) re: rollovers are dangerous, especially in SUVs
The idea behind this particular battery of tests is to simulate the kinds of forces that can cause a vehicle to lose stability and roll over. Force applied to the side of a vehicle while it's moving forward is called lateral acceleration. As it pushes against a car's center of gravity it can disorient the vehicle, causing a loss of control for the driverŠor worse. Using NASA's centrifuge, engineers can test the limits of different vehicle models by steadily increasing the lateral acceleration. A congressional mandate directed NHTSA to develop new rollover testing procedures for passenger vehicles. That's how the D-O-T testing team wound up here. This colossal device fills an entire building-the business part of which is housed in a drab, surreal rotunda more than 150 feet in diameter. Beneath the floorŠtwo powerful motorsŠeach capable of 1250 horsepower can propel the arm to speeds able to exert up to 30 times the force of gravity on the outer part of the test platform. These tests won't get even close to those limits-at little more than one G laterally, the giant machine hardly even works up a sweat. But in engineering terms, the payoff is expected to be large and in this first-of-its-kind collaboration, NHTSA and NASA hope their combined know-how will someday be useful to the many millions of drivers traveling the nations billions of miles of roads.
Courtesy: NASA
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| ITEM (2): All Wheels Forward -- VO - Accidents involving rollovers can be deadly. That's why federal highway safety officials came to NASA. By testing a variety of ordinary cars and SUVs on the space agency's giant centrifuge, they hope to learn more about how to prevent rollovers from happening. The findings will not only be useful for drivers, but also for automobile manufacturersŠalways looking for ways to enhance their safety designs.
Courtesy: NASA
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| ITEM (3): New Kinds of Tests--NHTSA Turns to the Space Agency - Following investigations after the widely reported factory recall of Firestone tires, Congress mandated that NHTSA develop a dynamic rollover test for vehicles. That's why the Highway Administration approached the one federal agency with an out-of-this-world record for vehicle performance tests. By leveraging the strengths of both agencies, officials at NASA and NHTSA expect this first-of-its-kind test will enable them to learn valuable safety information about vehicles that continue to move millions of Americans every day. Courtesy: NASA |
| ITEM (4): One Car, Several Trucks and SUVs, No Satellites Anywhere - Before placing the first actual test vehicle on the test platform, a 1993 Chevrolet Caprice went around the room. The Chevy simply allowed engineers to polish their procedures prior to placing other subject vehicles on the platform. After putting the sedan through its paces, the experimenters used the massive overhead crane to swap the Chevy for each SUV and light truck. Typically the main platform on the centrifuge supports hardware that's being tested prior to being sent into space. These experiments replace spacecraft and flight hardware with the kinds of machines that might instead be found in a driveway or parking space. Courtesy: NASA
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| ITEM (5): Keeping Four on the Floor - Using the space agency's High Capacity Centrifuge at the Goddard Space Flight Center, Highway Administration officials spun ordinary cars, trucks, and SUVs on a test platform to study their rollover limits. While immensely popular for their large cargo capacities and muscular driving characteristics, sport utility vehicles are more prone to tip over in a turn than ordinary sedans. With comparatively higher bodies and ground clearances, they tend to have high centers of gravity, characteristic which makes rollovers more likely. These tests at NASA will help officials study the physical limits of several makes and models, providing valuable insights into automotive safety.
Courtesy: NASA
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| ITEM (6): Center of Gravity--Why Rollovers Happen
(animation) - A particular object's center of gravity--in this case an SUV--will always be contained within the geometric confines of that vehicle as it's oriented in space relative to the pull of gravity. If there's a change in a vehicle's spatial orientation due to the imposition of some external force, the vehicle's center of gravity will shift from its original position as long as that external force persists. That means that the tires, which had supported a vehicle's center of gravity, begin to lose their usefulness as supporting structures relative to the pull of gravity. As a result, the vehicle seeks a new structural support relative to the pull of gravity, like its side or roof. If this change happens fast enough, the vehicle will not only fall over: it will roll.
Courtesy: NASA
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| ITEM (7): The Centrifuge--How it Works, What it Does
- By spinning flight hardware at high speeds, engineers can subject it to many times the force of Earth's gravity--forces that approximate similar effects that satellites will undergo during the rigors of a rocket launch. By testing hardware on a centrifuge, project managers and engineers can both validate a satellite's structural integrity prior to lift-off, as well as help refine potential problems.
Courtesy: NASA
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| ITEM (8): The Nature of the Spinning Beast - It is a big machine. With is two powerful motors running at full tilt, the outer edge of the test arm can reach speeds of two hundred miles an hour. But it's also a finely tuned machine. At rest, the giant multi-ton arm sits on bearings so smooth that just two or three people can push it around the room. The High Capacity Centrifuge is so large that when it was built in the mid-1960s, architects actually build the machine and the building simultaneously, starting with a special foundation to house the spinning behemoth's two motors underground.
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| ITEM (9): Full Tank, Fake Driver, Going in Circles
- Engineers have filled each vehicle's gas tank with a comparatively inert liquid called Stoddard fluid, a solvent with similar physical properties to gasoline. As the vehicle spins, the liquid sloshes to one side of the gas tank just like real gasoline will do in a real-world situation. A crash test dummy will also go along for the ride. Sitting in the driver's seat, the dummy becomes part of the physical environment that describes the vehicle. Without the shape and weight of a person, the test cannot be run as accurately as it otherwise might. Engineers expect that they will only have to push the vehicles little more than one G laterally to collect all the useful information they need.
Courtesy: NASA
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| ITEM (10): What are G Forces? - Gravity is one of the four fundamental physical forces. It's a function of an object's mass; it's the force that draws bodies together through space. A machine designed for space flight must obviously leave the Earth's surface by overcoming the force of gravity. To do this, it must endure forces greater than it encounters on the surface. Every time that force increases by the equivalent of one unit of Earth's gravity, it's said to increase by one "G". On a centrifuge, however, G forces are a function of how much force is being applied to spinning test objects. As the force increases by a factor equal to one unit of Earth's gravity, the "G" forces acting upon the test subject rise commensurately.
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| ITEM (11): TRMMing the Sails before Launch - Prior to launch aboard a Japanese H-2 rocket, the joint U.S./Japanese research satellite called TRMM (Tropical Rainfall Measuring Mission) made the rounds of NASA's engineering division--many rounds, in fact. During its preflight validation, engineers spun TRMM on the High Capacity Centrifuge at the Goddard Space Flight Center. These tests helped insure that the complex research vehicle could withstand the rigors of launch. On November 27, 1997, the rocket tasked to put TRMM into space lifted of from the Tanegashima Space Center in Japan. Since then, the satellite has performed like a champ, delivering state of the art data about various aspects of the Earth's climate.
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| ITEM (12): Applied Research: Partnerships and Innovation
- History has shown that the United States space program finds its biggest dividend in the ancillary uses of the technologies that were developed in order for humans and their machines to leave the planet. By applying some of those technologies and skills to research pursuits that affect everyday life---in this case automotive safety-- ordinary citizens can reap the benefits of programs that on the surface might only seem like the stuff of stargazing.
Courtesy: NASA
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| ITEM (13): What Should You Do to Prevent Rollovers? - Perhaps most important, don't speed. The force tending to tip a vehicle over on a curved path increases substantially as the speed around the curve increases. Further, the sharper the turn, the higher the tipping force. That's why increases in speed can dramatically increase the possibility of tipping over on a curved road. A typical SUV has a high center of gravity, which provides more leverage to tip over when the tipping force is high. Avoid sudden lateral shifts. Lane changes should happen smoothly, with plenty of clearance in front and behind your vehicle. Take turns at angles that facilitate good connections between your tires and the road. Maintain your full attention on the task of driving. Alcohol, sleep deprivation, distractions from passengers, and distraction from other activities like cell phones and car stereos can all contribute to unexpected changes in the orientation of a vehicle.
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| ITEM (14): Selected Soundbites With Carmine Mattiello,
Section Head for Structural Dynamics, Test Engineering Section and Stephen Kratzke, NHTSA Associate Administrator, Rulemaking
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