The Laser Dynamic Range Imager (LDRI) is a

LIDAR Lidar (, also LIDAR, or LiDAR; sometimes LADAR) is a method for determining ranges (variable distance) by targeting an object or a surface with a laser and measuring the time for the reflected light to return to the receiver. It can also be ...

range imaging Range imaging is the name for a collection of techniques that are used to produce a 2D image showing the distance to points in a scene from a specific point, normally associated with some type of sensor device. The resulting range image has pix ...

device developed by

Sandia National Laboratories Sandia National Laboratories (SNL), also known as Sandia, is one of three research and development laboratories of the United States Department of Energy's National Nuclear Security Administration (NNSA). Headquartered in Kirtland Air Force Ba ...

for the US

Space Shuttle program The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its ...

. The sensor was developed as part of

NASA The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding t ...

's "Return to Flight" effort following the

Space Shuttle Columbia disaster The Space Shuttle ''Columbia'' disaster was a fatal accident in the United States space program that occurred on February 1, 2003. During the STS-107 mission, Space Shuttle ''Columbia'' disintegrated as it reentered the atmosphere over Texa ...

to provide 2-D and 3-D images of the

thermal protection system Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entr ...

on the Space Shuttle Orbiter. The LDRI generates 3-dimensional images from 2-dimensional video. Modulated laser illumination is demodulated by the receive optics, and the resulting video sequences can be processed to produce 3-d images. The modulation produces a flickering effect from frame-to-frame in the video imagery. As part of the

Orbiter Boom Sensor System The Orbiter Boom Sensor System (OBSS) was a 50-foot (15.24 m) boom carried on board NASA's Space Shuttles. The boom was grappled by the Canadarm and served as an extension of the arm, doubling its length to a combined total of 100 feet (30 m). At ...

, the LDRI is mounted at the end of the boom on a pan-

tilt Tilt may refer to: Music * Tilt (American band), a punk rock group, formed in 1992 * Tilt (British band), an electronic music group, formed in 1993 * Tilt (Polish band), a rock band, formed in 1979 Albums * ''Tilt'' (Cozy Powell album), 1981 * ...

unit (PTU) along with an intensified video camera (ITVC). During 2-dimensional imaging of the reinforced carbon-carbon panels on the leading edge of the shuttle's wings, the LDRI is capable of seeing damage as small as a 0.020-inch crack. During the mission

STS-114 STS-114 was the first "Return to Flight" Space Shuttle mission following the Space Shuttle Columbia disaster, Space Shuttle ''Columbia'' disaster. Space Shuttle Discovery, ''Discovery'' launched at 10:39 Eastern Time Zone, EDT (14:39 Coordinated ...

, the LDRI was used to obtain 3-D measurements of a loose gap filler on the underside of the orbiter. The LDRI also flew on the subsequent mission,

STS-121 STS-121 was a 2006 NASA Space Shuttle mission to the International Space Station (ISS) flown by . The main purposes of the mission were to test new safety and repair techniques introduced following the ''Columbia'' disaster of February 2003 as w ...

. On this mission,

NASA TV The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding th ...

broadcast live raw video from the LDRI of the entire wing leading edge and nosecap surveys on flight day 2. An earlier version of the LDRI originally flew as a DTO on

STS-97 STS-97 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle '' Endeavour''. The crew installed the first set of solar arrays to the ISS, prepared a docking port for arrival of the Destiny Laboratory Module, ...

.STS-97 DTO: Laser Dynamic Range Imager (LDRI)
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References

Lidar Space Shuttle program Sandia National Laboratories Space-based laser {{technology-stub