skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Updated Population and Risk Assessment for Airbursts from Near-Earth Objects (NEOs).

Abstract

Abstract not provided.

Authors:
; ;
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
National Aeronautic and Space Administration (NASA)
OSTI Identifier:
1246859
Report Number(s):
SAND2015-1735C
579754
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: Proposed for presentation at the IEEE Aerospace Conference 2015 held March 7-14, 2015 in Big Sky, MT.
Country of Publication:
United States
Language:
English

Citation Formats

Boslough, Mark B., Brown, Peter, and Harris, Alan. Updated Population and Risk Assessment for Airbursts from Near-Earth Objects (NEOs).. United States: N. p., 2015. Web.
Boslough, Mark B., Brown, Peter, & Harris, Alan. Updated Population and Risk Assessment for Airbursts from Near-Earth Objects (NEOs).. United States.
Boslough, Mark B., Brown, Peter, and Harris, Alan. Sun . "Updated Population and Risk Assessment for Airbursts from Near-Earth Objects (NEOs).". United States. doi:. https://www.osti.gov/servlets/purl/1246859.
@article{osti_1246859,
title = {Updated Population and Risk Assessment for Airbursts from Near-Earth Objects (NEOs).},
author = {Boslough, Mark B. and Brown, Peter and Harris, Alan},
abstractNote = {Abstract not provided.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Sun Mar 01 00:00:00 EST 2015},
month = {Sun Mar 01 00:00:00 EST 2015}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • Abstract not provided.
  • Only a very small fraction of the asteroid population at size scales comparable to the object that exploded over Chelyabinsk, Russia has been discovered to date, and physical properties are poorly characterized. We present previously unreported detections of 105 close approaching near-Earth objects (NEOs) by the Wide-field Infrared Survey Explorer (WISE) mission's NEOWISE project. These infrared observations constrain physical properties such as diameter and albedo for these objects, many of which are found to be smaller than 100 m. Because these objects are intrinsically faint, they were detected by WISE during very close approaches to the Earth, often at largemore » apparent on-sky velocities. We observe a trend of increasing albedo with decreasing size, but as this sample of NEOs was discovered by visible light surveys, it is likely that selection biases against finding small, dark NEOs influence this finding.« less
  • Ecological risk can be assessed at different levels of biological organization: biochemical, whole animal, populations and communities. Each level is characterized by varying degrees of contaminant sensitivity, response time, causal linkage and ecological interpretation. Whole animal bioassays are used in research and regulatory programs to assess contaminant impacts. In many ways, bioassays represent a compromise between the need for rapid, sensitive testing and the desire to measure ecologically important endpoints. Population demographic models represent a tool for interpreting bioassay results. They integrate life-history information and project population-level contaminant effects. Four important research issues must be addressed before demographic models canmore » be fully utilized in this manner. Assumptions and extrapolations accompanying many models must be critically examined; e.g. assumption of no density-dependence and spatial/temporal extrapolations. Laboratory-based models must be calibrated with field-derived demographic models. Population models must be coupled with exposure models to characterize contaminant risk. Finally, field verification studies must be conducted to evaluate the accuracy of demographic model predictions.« less
  • The Earth is periodically hit by near Earth objects (NEOs) ranging in size from dust to mountains. The small ones are a useful source of information, but those larger than about 1 km can cause global damage. The requirements for the deflection of NEOs with significant material strength are known reasonably well; however, the strength of large NEOs is not known, so those requirements may not apply. Meteor impacts on the Earth`s atmosphere give some information on strength as a function of object size and composition. This information is used here to show that large, weak objects could also bemore » deflected efficiently, if addressed properly.« less
  • The performance capabilities and technology features of ultra compact nuclear thermal rockets based on very high power density ({approximately} 30 Megawatts per liter) fuel elements are described. Nuclear rockets appear particularly attractive for carrying out missions to investigate or intercept Near Earth Objects (NEOS) that potentially could impact on the Earth. Many of these NEO threats, whether asteroids or comets, have extremely high closing velocities, i.e., tens of kilometers per second relative to the Earth. Nuclear rockets using hydrogen propellant enable flight velocities 2 to 3 times those achievable with chemical rockets, allowing interaction with a potential NEO threat atmore » a much shorter time, and at much greater range. Two versions of an ultra compact nuclear rocket based on very high heat transfer rates are described: the PBR (Particle Bed Reactor), which has undergone substantial hardware development effort, and MITEE (Miniature Reactor Engine) which is a design derivative of the PBR. Nominal performance capabilities for the PBR are: thermal power - 1000 MW thrust - 45,000 lbsf, and weight - 500 kg. For MITEE, nominal capabilities are: thermal power - 100 MW; thrust {approx} 4500 lbsf, and weight - 50 kg. Development of operational PBR/MITEE systems would enable spacecraft launched from LEO (Low Earth Orbit) to investigate intercept NEO`s at a range of {approximately} 100 million kilometers in times of {approximately} 30 days.« less