This paper presents laboratory measurements and analysis of optical spectral bidirectional reflec... more This paper presents laboratory measurements and analysis of optical spectral bidirectional reflectance distribution functions of materials commonly found on the surfaces of spacecraft. A goniospectrometer sensitive to light with wavelengths between 350 and 1100 nm was constructed, and four classes of materials were studied in a variety of illumination and observational geometries: triple-junction photovoltaic cells, aluminum, white-coated metallic surface, and aluminized polyimide films. The measurements were analyzed to study how specific materials could be characterized based on their spectral bidirectional reflectance distribution function and how it varies with changing illumination and observational geometry. In the end, the experiment yielded two significant outcomes. First, the results provide a better understanding of how the spectral energy distribution of light reflected from these materials behaves as the illumination and observational geometry is varied. This result will be particularly useful...
In February 2007 dedicated observations were made of the orbital space predicted to contain debri... more In February 2007 dedicated observations were made of the orbital space predicted to contain debris from the breakup of the Titan 3C-4 transtage back on 21 February 1992. These observations were carried out on the Michigan Orbital DEbris ...
... financially of this project. The authors would also like to thank Brian Birge for his assista... more ... financially of this project. The authors would also like to thank Brian Birge for his assistance with the particle swarm theory. Also, thanks goes to Dr. Bruce Hapke who kindly explained his program in great detail. In addition, many ...
... of LEGEND simulated debris patterns for 2001, 2003, 2006 along with the Catalog elements for ... more ... of LEGEND simulated debris patterns for 2001, 2003, 2006 along with the Catalog elements for ... 5.2 Correlation Between All UCTs Observed During Run To determine how much confidence to ... 1. Schildknecht, T., et al., Optical Observations of Space Debris in High-Altitude Orbits ...
Page 1. Optical Properties of Multi-Layered Insulation Heather M. Rodriguez and Kira J. Abercromb... more Page 1. Optical Properties of Multi-Layered Insulation Heather M. Rodriguez and Kira J. Abercromby ESCG/Jacobs Sverdrup PO Box 58447, Houston, TX 77058-8447 E-mail: [email protected] Mark Mulrooney ...
Orbital debris represents a significant risk to operational spacecraft. We report on BVRI observa... more Orbital debris represents a significant risk to operational spacecraft. We report on BVRI observations from the Cerro Tololo Inter-American Observatory (CTIO) to determine the characteristics of optically faint debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m Curtis-Schmidt telescope (known as MODEST, for Michigan Orbital DEbris
For 14 nights in March 2007, we used two telescopes at the Cerro Tololo Inter-American Observator... more For 14 nights in March 2007, we used two telescopes at the Cerro Tololo Inter-American Observatory (CTIO) in Chile to study the nature of space debris at Geosynchronous Earth Orbit (GEO).
There are over 250 active spacecraft in the geosynchronous Earth orbit (GEO) regime, with another... more There are over 250 active spacecraft in the geosynchronous Earth orbit (GEO) regime, with another 500 inactive or debris pieces in the public catalog. Their orbits are primarily perturbed by gravitational effects from the Earth, Moon, and Sun, with inclination increasing from zero degrees to 15 degrees and back to zero over a 54 year period. We will review the dynamics of objects at GEO, and then show results from an optical survey for faint GEO debris with the University of Michigan's Curtis-Schmidt telescope at Cerro Tololo. Recently the CTIO 0.9-m was used to follow-up debris discoveries made with the Schmidt, and determine orbits and colors. Faint GEO debris has a very different angular rate and orbital distribution than bright debris. The consensus is that these objects have high area-to-mass (A/M) and their orbits are significantly perturbed by solar radiation. This is a classic problem of applied astronomy: using modern methods of imaging and astrometry to measure the di...
Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter ... more Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan telescope `Walter Baade' at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe preliminary results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r' filter. The limiting mag...
The University of Michigan's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observat... more The University of Michigan's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory is dedicated to an optical survey for faint space debris at geosynchronous orbit (GEO) for NASA. In the public catalog in or near the GEO regime, there are over 250 active spacecraft, and more than 500 large inactive spacecraft and debris pieces. The purpose of the Schmidt GEO survey
To better characterize and model optical data acquired from ground-based telescopes, the Optical ... more To better characterize and model optical data acquired from ground-based telescopes, the Optical Measurements Center (OMC) at NASA/JSC attempts to emulate illumination conditions seen in space using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. Equipment in the OMC includes a 75-watt Xenon arc lamp, used as a solar simulator; a Santa Barbara Instrument Group CCD camera with
Optical observations of orbital debris offer insights that differ from radar measurements (specif... more Optical observations of orbital debris offer insights that differ from radar measurements (specifically the size parameter and wavelength regime). For example, time-dependent photometric data yield lightcurves in multiple bandpasses that aid in material identification and possible periodic orientations. This data can also be used to help identify shapes and optical properties at multiple phase angles. Capitalizing on optical data products and applying them to generate a more complete understanding of orbital space objects, is a key objective of NASA's Optical Measurement Program, and a primary driver for creation of the Optical Measurements Center (OMC). The OMC attempts to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC uses a 300 Watt Xenon arc lamp as a solar simulator, a CCD camera with Johnson/Bessel colored filters, and a robotic arm to orientate/rotate objects ...
... laboratory properties with the intent of ascertaining the intrinsic properties of the observe... more ... laboratory properties with the intent of ascertaining the intrinsic properties of the observed orbitaldebris. ... A 75-watt, Xenon arc lamp simulates solar illumination through the spectral range of ... thus allowing for a more efficient and accurate method for dimensional analysis [3]. The ...
We report on a continuing program of optical photometric measurements of faint orbital debris at ... more We report on a continuing program of optical photometric measurements of faint orbital debris at geosynchronous Earth orbit (GEO). These observations can be compared with laboratory studies of actual spacecraft materials in an effort to determine what the faint debris at GEO may be.
This paper presents laboratory measurements and analysis of optical spectral bidirectional reflec... more This paper presents laboratory measurements and analysis of optical spectral bidirectional reflectance distribution functions of materials commonly found on the surfaces of spacecraft. A goniospectrometer sensitive to light with wavelengths between 350 and 1100 nm was constructed, and four classes of materials were studied in a variety of illumination and observational geometries: triple-junction photovoltaic cells, aluminum, white-coated metallic surface, and aluminized polyimide films. The measurements were analyzed to study how specific materials could be characterized based on their spectral bidirectional reflectance distribution function and how it varies with changing illumination and observational geometry. In the end, the experiment yielded two significant outcomes. First, the results provide a better understanding of how the spectral energy distribution of light reflected from these materials behaves as the illumination and observational geometry is varied. This result will be particularly useful...
In February 2007 dedicated observations were made of the orbital space predicted to contain debri... more In February 2007 dedicated observations were made of the orbital space predicted to contain debris from the breakup of the Titan 3C-4 transtage back on 21 February 1992. These observations were carried out on the Michigan Orbital DEbris ...
... financially of this project. The authors would also like to thank Brian Birge for his assista... more ... financially of this project. The authors would also like to thank Brian Birge for his assistance with the particle swarm theory. Also, thanks goes to Dr. Bruce Hapke who kindly explained his program in great detail. In addition, many ...
... of LEGEND simulated debris patterns for 2001, 2003, 2006 along with the Catalog elements for ... more ... of LEGEND simulated debris patterns for 2001, 2003, 2006 along with the Catalog elements for ... 5.2 Correlation Between All UCTs Observed During Run To determine how much confidence to ... 1. Schildknecht, T., et al., Optical Observations of Space Debris in High-Altitude Orbits ...
Page 1. Optical Properties of Multi-Layered Insulation Heather M. Rodriguez and Kira J. Abercromb... more Page 1. Optical Properties of Multi-Layered Insulation Heather M. Rodriguez and Kira J. Abercromby ESCG/Jacobs Sverdrup PO Box 58447, Houston, TX 77058-8447 E-mail: [email protected] Mark Mulrooney ...
Orbital debris represents a significant risk to operational spacecraft. We report on BVRI observa... more Orbital debris represents a significant risk to operational spacecraft. We report on BVRI observations from the Cerro Tololo Inter-American Observatory (CTIO) to determine the characteristics of optically faint debris at geosynchronous Earth orbit (GEO). Our sample is taken from GEO objects discovered in a survey with the University of Michigan's 0.6-m Curtis-Schmidt telescope (known as MODEST, for Michigan Orbital DEbris
For 14 nights in March 2007, we used two telescopes at the Cerro Tololo Inter-American Observator... more For 14 nights in March 2007, we used two telescopes at the Cerro Tololo Inter-American Observatory (CTIO) in Chile to study the nature of space debris at Geosynchronous Earth Orbit (GEO).
There are over 250 active spacecraft in the geosynchronous Earth orbit (GEO) regime, with another... more There are over 250 active spacecraft in the geosynchronous Earth orbit (GEO) regime, with another 500 inactive or debris pieces in the public catalog. Their orbits are primarily perturbed by gravitational effects from the Earth, Moon, and Sun, with inclination increasing from zero degrees to 15 degrees and back to zero over a 54 year period. We will review the dynamics of objects at GEO, and then show results from an optical survey for faint GEO debris with the University of Michigan's Curtis-Schmidt telescope at Cerro Tololo. Recently the CTIO 0.9-m was used to follow-up debris discoveries made with the Schmidt, and determine orbits and colors. Faint GEO debris has a very different angular rate and orbital distribution than bright debris. The consensus is that these objects have high area-to-mass (A/M) and their orbits are significantly perturbed by solar radiation. This is a classic problem of applied astronomy: using modern methods of imaging and astrometry to measure the di...
Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter ... more Existing optical surveys for debris at geosynchronous orbit (GEO) have been conducted with meter class telescopes, which have detection limits in the range of 18th-19th magnitude. We report on a new search for optically faint debris at GEO using the 6.5-m Magellan telescope `Walter Baade' at Las Campanas Observatory in Chile. Our goal is to go as faint as possible and characterize the brightness distribution of debris fainter than R = 20th magnitude, corresponding to a size smaller than 10 cm assuming an albedo of 0.175. We wish to compare the inferred size distribution for GEO debris with that for LEO debris. We describe preliminary results obtained during 9.4 hours of observing time during 25-27 March 2011. We used the IMACS f/2 instrument, which has a mosaic of 8 CCDs, and a field of view of 30 arc-minutes in diameter. This is the widest field of view of any instrument on either Magellan telescope. All observations were obtained through a Sloan r' filter. The limiting mag...
The University of Michigan's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observat... more The University of Michigan's Curtis-Schmidt telescope at Cerro Tololo Inter-American Observatory is dedicated to an optical survey for faint space debris at geosynchronous orbit (GEO) for NASA. In the public catalog in or near the GEO regime, there are over 250 active spacecraft, and more than 500 large inactive spacecraft and debris pieces. The purpose of the Schmidt GEO survey
To better characterize and model optical data acquired from ground-based telescopes, the Optical ... more To better characterize and model optical data acquired from ground-based telescopes, the Optical Measurements Center (OMC) at NASA/JSC attempts to emulate illumination conditions seen in space using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. Equipment in the OMC includes a 75-watt Xenon arc lamp, used as a solar simulator; a Santa Barbara Instrument Group CCD camera with
Optical observations of orbital debris offer insights that differ from radar measurements (specif... more Optical observations of orbital debris offer insights that differ from radar measurements (specifically the size parameter and wavelength regime). For example, time-dependent photometric data yield lightcurves in multiple bandpasses that aid in material identification and possible periodic orientations. This data can also be used to help identify shapes and optical properties at multiple phase angles. Capitalizing on optical data products and applying them to generate a more complete understanding of orbital space objects, is a key objective of NASA's Optical Measurement Program, and a primary driver for creation of the Optical Measurements Center (OMC). The OMC attempts to emulate space-based illumination conditions using equipment and techniques that parallel telescopic observations and source-target-sensor orientations. The OMC uses a 300 Watt Xenon arc lamp as a solar simulator, a CCD camera with Johnson/Bessel colored filters, and a robotic arm to orientate/rotate objects ...
... laboratory properties with the intent of ascertaining the intrinsic properties of the observe... more ... laboratory properties with the intent of ascertaining the intrinsic properties of the observed orbitaldebris. ... A 75-watt, Xenon arc lamp simulates solar illumination through the spectral range of ... thus allowing for a more efficient and accurate method for dimensional analysis [3]. The ...
We report on a continuing program of optical photometric measurements of faint orbital debris at ... more We report on a continuing program of optical photometric measurements of faint orbital debris at geosynchronous Earth orbit (GEO). These observations can be compared with laboratory studies of actual spacecraft materials in an effort to determine what the faint debris at GEO may be.
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Papers by K. Abercromby