E. Stansbery | NASA - Johnson Space Center (original) (raw)
Papers by E. Stansbery
The Genesis mission, launched in August 2001, is collecting samples of the solar wind and will re... more The Genesis mission, launched in August 2001, is collecting samples of the solar wind and will return to Earth in 2004. Genesis can be viewed as the most fundamental of NASA's sample return missions because it is expected to provide insight into the initial elemental and isotopic composition of the solar nebula from which all other planetary objects formed. The
Eos, Transactions American Geophysical Union, 2002
The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first... more The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first spacecraft ever to return from interplanetary space. The fifth in NASAs line of low-cost, Discovery-class missions, its goal is to collect samples of solar wind and return them ...
Journal of Geophysical Research, 1993
An axisymmetric numerical model in an Earth-centered spherical coordinate system is created to ca... more An axisymmetric numerical model in an Earth-centered spherical coordinate system is created to calculate the electric field distribution and current distribution from a thunderstorm source in the global electrical circuit. The model includes a hemisphere in which the thunderstorm is located, an atmosphere and ionosphere with anisotropic height-variable conductivities, and a passive magnetic conjugate hemisphere. Both single-cell thunderstorms and symmetric multicell thunderstorm complexes can be modeled. The current output from the thunderstorm spreads out in the ionosphere and flows along the magnetic field lines into the conjugate hemisphere. Approximately half of the current that reaches the ionosphere flows into the conjugate hemisphere, and the rest is redirected to the fair-weather portion of the storm hemisphere. Two examples of this general model are discussed, a single-cell severe storm and a multicell severe storm. Results of this study show that it is important to include a realistic model of the ionosphere to evaluate the spread of current in the ionosphere and the mechanism of thunderstorm charging of the global electric circuit.
Acta Astronautica, 1996
The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of m... more The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.
Inspection of the Genesis Science Canister revealed a micrometeorite impact, white paint discolor... more Inspection of the Genesis Science Canister revealed a micrometeorite impact, white paint discoloration, and black residue adhering to the structure. Loose particles were removed with a fine-haired brush and filter-trap vacuum.
Spectroscopic ellipsometry models are discussed that determine accurate thickness measurements of... more Spectroscopic ellipsometry models are discussed that determine accurate thickness measurements of thin-film contamination on Genesis mission flown collector array materials.
The Genesis Mission, 2003
The Genesis Discovery mission will return samples of solar matter for analysis of isotopic and el... more The Genesis Discovery mission will return samples of solar matter for analysis of isotopic and elemental compositions in terrestrial laboratories. This is accomplished by exposing ultra-pure materials to the solar wind at the L1 Lagrangian point and returning the materials to Earth. Solar wind collection will continue until April 2004 with Earth return in Sept. 2004. The general science objectives of Genesis are to (1) to obtain solar isotopic abundances to the level of precision required for the interpretation of planetary science data, (2) to significantly improve knowledge of solar elemental abundances, (3) to measure the composition of the different solar wind regimes, and (4) to provide a reservoir of solar matter to serve the needs of planetary science in the 21st century. The Genesis flight system is a sun-pointed spinner, consisting of a spacecraft deck and a sample return capsule (SRC). The SRC houses a canister which contains the collector materials. The lid of the SRC and a cover to the canister were opened to begin solar wind collection on November 30, 2001. To obtain samples of O and N ions of higher fluence relative to background levels in the target materials, an electrostatic mirror ('concentrator') is used which focuses the incoming ions over a diameter of about 20 cm onto a 6 cm diameter set of target materials. Solar wind electron and ion monitors (electrostatic analyzers) determine the solar wind regime present at the spacecraft and control the deployment of separate arrays of collector materials to provide the independent regime samples.
Eos, Transactions American Geophysical Union, 2002
The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first... more The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first spacecraft ever to return from interplanetary space. The fifth in NASAs line of low-cost, Discovery-class missions, its goal is to collect samples of solar wind and return them ...
Spectroscopic ellipsometry results and images are used to assess the amount of surface contaminat... more Spectroscopic ellipsometry results and images are used to assess the amount of surface contamination on Genesis silicon carbide concentrator target 60003. Ellipsometry data show possible material substrate alteration by solar wind radiation.
UPW/Megasonic cleaning appears to be a rapid, simple way to remove larger particles from Genesis ... more UPW/Megasonic cleaning appears to be a rapid, simple way to remove larger particles from Genesis array collector fragments.
The cleaning efficiency of the Genesis Ultra-pure Water Megasonic Wafer Spin Cleaner will be pres... more The cleaning efficiency of the Genesis Ultra-pure Water Megasonic Wafer Spin Cleaner will be presented. Results show the effectiveness of the new cleaner removing particle contamination from Genesis silicon wafers implanted with solar wind.
Basic characterization of Genesis solar wind array collector fragments consists of solar regime i... more Basic characterization of Genesis solar wind array collector fragments consists of solar regime identification, whole fragment surface condition imaging, particle density imaging, and molecular film thickness. Fragment catalogs are in work.
The polished aluminum collector, part of the Genesis Mission Early Science Return, was extracted ... more The polished aluminum collector, part of the Genesis Mission Early Science Return, was extracted from the damaged canister intact, but bent and with a few mud spatters. Pre- and post-flight curation handling and subdivision of the collector by sawing is described.
XPS and spectroscopic ellipsometry are used to evaluate the effectiveness of UV ozone cleaning fo... more XPS and spectroscopic ellipsometry are used to evaluate the effectiveness of UV ozone cleaning for removing a carbon based surface contaminate on silicon and sapphire semiconductor materials from NASA's Genesis solar wind sample return mission.
The Genesis mission, launched in August 2001, is collecting samples of the solar wind and will re... more The Genesis mission, launched in August 2001, is collecting samples of the solar wind and will return to Earth in 2004. Genesis can be viewed as the most fundamental of NASA's sample return missions because it is expected to provide insight into the initial elemental and isotopic composition of the solar nebula from which all other planetary objects formed. The
Eos, Transactions American Geophysical Union, 2002
The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first... more The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first spacecraft ever to return from interplanetary space. The fifth in NASAs line of low-cost, Discovery-class missions, its goal is to collect samples of solar wind and return them ...
Journal of Geophysical Research, 1993
An axisymmetric numerical model in an Earth-centered spherical coordinate system is created to ca... more An axisymmetric numerical model in an Earth-centered spherical coordinate system is created to calculate the electric field distribution and current distribution from a thunderstorm source in the global electrical circuit. The model includes a hemisphere in which the thunderstorm is located, an atmosphere and ionosphere with anisotropic height-variable conductivities, and a passive magnetic conjugate hemisphere. Both single-cell thunderstorms and symmetric multicell thunderstorm complexes can be modeled. The current output from the thunderstorm spreads out in the ionosphere and flows along the magnetic field lines into the conjugate hemisphere. Approximately half of the current that reaches the ionosphere flows into the conjugate hemisphere, and the rest is redirected to the fair-weather portion of the storm hemisphere. Two examples of this general model are discussed, a single-cell severe storm and a multicell severe storm. Results of this study show that it is important to include a realistic model of the ionosphere to evaluate the spread of current in the ionosphere and the mechanism of thunderstorm charging of the global electric circuit.
Acta Astronautica, 1996
The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of m... more The Suess-Urey (S-U) mission has been proposed as a NASA Discovery mission to return samples of matter from the Sun to the Earth for isotopic and chemical analyses in terrestrial laboratories to provide a major improvement in our knowledge of the average chemical and isotopic composition of the solar system. The S-U spacecraft and sample return capsule will be placed in a halo orbit around the L1 Sun-Earth libration point for two years to collect solar wind ions which implant into large passive collectors made of ultra-pure materials. Constant Spacecraft-Sun-Earth geometries enable simple spin stabilized attitude control, simple passive thermal control, and a fixed medium gain antenna. Low data requirements and the safety of a Sun-pointed spinner, result in extremely low mission operations costs.
Inspection of the Genesis Science Canister revealed a micrometeorite impact, white paint discolor... more Inspection of the Genesis Science Canister revealed a micrometeorite impact, white paint discoloration, and black residue adhering to the structure. Loose particles were removed with a fine-haired brush and filter-trap vacuum.
Spectroscopic ellipsometry models are discussed that determine accurate thickness measurements of... more Spectroscopic ellipsometry models are discussed that determine accurate thickness measurements of thin-film contamination on Genesis mission flown collector array materials.
The Genesis Mission, 2003
The Genesis Discovery mission will return samples of solar matter for analysis of isotopic and el... more The Genesis Discovery mission will return samples of solar matter for analysis of isotopic and elemental compositions in terrestrial laboratories. This is accomplished by exposing ultra-pure materials to the solar wind at the L1 Lagrangian point and returning the materials to Earth. Solar wind collection will continue until April 2004 with Earth return in Sept. 2004. The general science objectives of Genesis are to (1) to obtain solar isotopic abundances to the level of precision required for the interpretation of planetary science data, (2) to significantly improve knowledge of solar elemental abundances, (3) to measure the composition of the different solar wind regimes, and (4) to provide a reservoir of solar matter to serve the needs of planetary science in the 21st century. The Genesis flight system is a sun-pointed spinner, consisting of a spacecraft deck and a sample return capsule (SRC). The SRC houses a canister which contains the collector materials. The lid of the SRC and a cover to the canister were opened to begin solar wind collection on November 30, 2001. To obtain samples of O and N ions of higher fluence relative to background levels in the target materials, an electrostatic mirror ('concentrator') is used which focuses the incoming ions over a diameter of about 20 cm onto a 6 cm diameter set of target materials. Solar wind electron and ion monitors (electrostatic analyzers) determine the solar wind regime present at the spacecraft and control the deployment of separate arrays of collector materials to provide the independent regime samples.
Eos, Transactions American Geophysical Union, 2002
The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first... more The Genesis spacecraft, launched on 8 August 2001 from Cape Canaveral, Florida, will be the first spacecraft ever to return from interplanetary space. The fifth in NASAs line of low-cost, Discovery-class missions, its goal is to collect samples of solar wind and return them ...
Spectroscopic ellipsometry results and images are used to assess the amount of surface contaminat... more Spectroscopic ellipsometry results and images are used to assess the amount of surface contamination on Genesis silicon carbide concentrator target 60003. Ellipsometry data show possible material substrate alteration by solar wind radiation.
UPW/Megasonic cleaning appears to be a rapid, simple way to remove larger particles from Genesis ... more UPW/Megasonic cleaning appears to be a rapid, simple way to remove larger particles from Genesis array collector fragments.
The cleaning efficiency of the Genesis Ultra-pure Water Megasonic Wafer Spin Cleaner will be pres... more The cleaning efficiency of the Genesis Ultra-pure Water Megasonic Wafer Spin Cleaner will be presented. Results show the effectiveness of the new cleaner removing particle contamination from Genesis silicon wafers implanted with solar wind.
Basic characterization of Genesis solar wind array collector fragments consists of solar regime i... more Basic characterization of Genesis solar wind array collector fragments consists of solar regime identification, whole fragment surface condition imaging, particle density imaging, and molecular film thickness. Fragment catalogs are in work.
The polished aluminum collector, part of the Genesis Mission Early Science Return, was extracted ... more The polished aluminum collector, part of the Genesis Mission Early Science Return, was extracted from the damaged canister intact, but bent and with a few mud spatters. Pre- and post-flight curation handling and subdivision of the collector by sawing is described.
XPS and spectroscopic ellipsometry are used to evaluate the effectiveness of UV ozone cleaning fo... more XPS and spectroscopic ellipsometry are used to evaluate the effectiveness of UV ozone cleaning for removing a carbon based surface contaminate on silicon and sapphire semiconductor materials from NASA's Genesis solar wind sample return mission.