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Friday, July 17, 2020 | History

2 edition of Evaluation of trapped radiation model uncertainties for spacecraft design found in the catalog.

Evaluation of trapped radiation model uncertainties for spacecraft design

T. W. Armstrong

Evaluation of trapped radiation model uncertainties for spacecraft design

by T. W. Armstrong

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  • 32 Currently reading

Published by National Aeronautics and Space Administration, Marshall Space Flight Center, Available from NASA Center for AeroSpace Information, National Technical Information Service [distributor in MSFC, Ala, Hanover, MD, Springfield, VA .
Written in English

    Subjects:
  • Computer programs.,
  • Ionizing radiation -- Mathematical models.,
  • Magnetohydrodynamics -- Mathematical models.,
  • Radiation trapping.,
  • Space ships -- Design and construction.,
  • Van Allen radiation belts -- Mathematical models.

  • Edition Notes

    StatementT.W. Armstrong and B.L. Colborn.
    GenreMathematical models.
    SeriesNASA CR : -- 2000-210072, NASA contractor report -- NASA CR-2000-210072.
    ContributionsColborn, B. L., George C. Marshall Space Flight Center., United States. Office of Space Science. Space Environments and Effects Program .
    The Physical Object
    Paginationiii, 47 p. :
    Number of Pages47
    ID Numbers
    Open LibraryOL18876555M

      Mortality and morbidity risks from space radiation exposure are an important concern for astronauts participating in International Space Station (ISS) missions. NASA’s radiation limits set a 3% cancer fatality probability as the upper bound of acceptable risk and considers uncertainties in risk predictions using the upper 95% confidence level (CL) of the assessment. 2 The Trapped Particle Radiation Environment of Jupiter The Magnetosphere of Jupiter Jovian radiation belts The trapped proton population The trapped electron population 3 Effects of trapped particle radiation on spacecraft and components 4 Implementation in SPENVIS The Divene and Garrett model The GIRE model.

    The evaluation of the radiation environment for these missions can be extremely complex depending on the number of times the trajectory passes through the earth's radiation belts, how close the spacecraft passes to the sun, and how well known the radiation environment of the planet is. The uncertainty factor defined for the trapped proton. Radiation ε=emissivity at the wavelength mix corresponding to temperature T σ=Stefan-Bolzmann’s constant = x W/m2-K4 T is temperature in Kelvin q =εσT4 Primary energy transfer mechanism for spacecraft. Most spacecraft have large radiators to rid themselves of heat. q is the heat transfer per unit area and T is the surface.

      Cucinotta FA, Kim MY, Chappell L () Space radiation cancer risk projections and uncertainties- NASA TP 6. Committee for Evaluation of Space Radiation Cancer Risk Model, National Research Council () Technical evaluation of the NASA model for cancer risk to astronauts due to space radiation.   1 Introduction. An accurate empirical model of the hazardous radiation belt energetic proton environment for low and medium altitude satellites would be of practical value (Ginet et al., ).Many data sets have been collected from low‐altitude orbits but provide only a limited view (e.g., Adriani et al., ; Looper et al., ).Access to the entire trapped particle population requires.


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Evaluation of trapped radiation model uncertainties for spacecraft design by T. W. Armstrong Download PDF EPUB FB2

Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design 1. Introduction and Summary Background Trapped radiation models which describe the characteristics of protons and electrons in the Van Allen belts are essential in addressing numerous Earth-orbit spacecraft and mission design issues related to the ionizing radiation environment, such as.

Download Citation | Evaluation of Trapped Radiation Model Uncertainties for Spacecraft Design | The standard AP8 and AE8 models for predicting trapped proton and. The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties.

Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP.

LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Author: T. Armstrong and B. Colborn. The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties.

Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP, LDEF, NOAA) and Space Shuttle flights, on Russian Cited by: The standard AP8 and AE8 models for predicting trapped proton and electron environments have been compared with several sets of flight data to evaluate model uncertainties.

Model comparisons are made with flux, dose, and activation measurements made on various U.S. low-Earth orbit satellites (APEX, CRRES, DMSP, LDEF, NOAA) and Space Shuttle flights, on Russian satellites (Photon-8, Author: B.

Colborn and T. Armstrong. Space mission planners continue to experience challenges associated with human space flight. Concerned with the omnipresence of harmful ionizing radiation in space, at the mission design stage, mission planners must evaluate the amount of exposure the crew of a spacecraft is subjected to during the transit trajectory from low Earth orbit (LEO) to geosynchronous orbit (GEO) and beyond (free space).

The spacecraft radiation shielding evaluation metric proposed here examines existing data in a new way in order to aid designers in calibrating and tying the calculated performance regarding shielding materials and designs for the cislunar environment to the only long-term human exposure medical data available: that from the astronauts who have flown on the International Space Station (ISS).

NASA's proposed space radiation cancer risk assessment model for radiation-induced cancer in astronauts is described in the NASA report Space Radiation Cancer Risk Projections and Uncertainties— (Cucinotta et al., ).

That NASA report, as it is called hereafter, is divided into discussions of the various components of the proposed model, including the discussion of the key. The trapped proton peak flux environment is typically used to evaluate SEE (mostly SEU).

Figures 10a and 10b show the peak integral proton spectra referenced to 10 MeV. Contrary to the IESD design environment, we commonly use the peak proton flux environment for the SEE evaluation without any additional margin even when using the AP8 model output.

• Characterize polyethylene-shielded radiation environment on International Space Station including the Service Module Zvezda crew quarters in order to optimize retro-fit shield design for ISS. Approach • Perform detailed modeling of ionizing radiation environment and measurements using in situ shielding material and radiation detectors.

Therefore, in an effort to reduce risk uncertainty for cancer development during deep space travel, we employed an Mlh1+/− mouse model to study the effects high-LET 56Fe ion space-like radiation.

The radiation belts and plasma in the Earth’s magnetosphere pose hazards to satellite systems which restrict design and orbit options with a resultant impact on mission performance and cost.

For decades the standard space environment specification used for spacecraft design has been provided by the NASA AE8 and AP8 trapped radiation belt models.

There are well-known limitations on their. 1. Introduction. A standard method for estimating trapped radiation for Earth orbiting spacecraft utilizes the spacecraft’s orbital parameters to compute the magnetic field B, and McIlwain’s L coordinates at the spacecraft as a function of location and time.

With these orbital data in hand, various versions of trapped radiation models, e.g., AP8 (Sawyer and Vette, ), AE8 (Vette, The designer should be aware of design guidelines to avoid surface and internal charging problems (Sections and ).

All guidelines should be considered in the spacecraft design and applied appropriately to the given mission. Analysis. Analysis should be used to evaluate a design for charging in the specified orbital environment.

For space radiation risk assessments, the major uncertainties in cancer prediction are Radiation quality effects on biological damage related to the qualitative and quantitative differences between space radiation compared to X rays Dependence of risk on dose-rates in space related to the biology of deoxyribonucleic acid (DNA).

To explore the design space of this capability, the sensitivity of solutions to spacecraft mass, fuel quantity, initial orbit, solar power collection, and battery size is demonstrated.

Oh D. Y., “ Evaluation of Solar Electric Propulsion Technologies for Discovery-Class Missions “ Trapped Radiation Model Uncertainties: Model–Data. components, radiation effects have taken on a new significance in spacecraft design. The push toward "cheaper, better, faster" spacecraft has acerbated the trend toward increasingly more radiation sensitive parts.

Indeed, trapped radiation effects on microelectronics have been and are continuing concerns for all. radiation is low intensity, the particles associated with galactic cosmic radiation have a high level of energy and cannot be shielded with current spacecraft design technologies.

The second form is trapped radiation, which occurs when radiation becomes trapped in Earth’s magnetic field. This type of radiation is not a problem outside of. The AE9/AP9-IRENE climatology models integrate the latest observations and science into a tool satellite designers can use to develop radiation specifications for missions traversing the Earth’s radiation belts.

The model covers trapped radiation and plasma from keV to GeV energies. JSC SPACE RADIATION CANCER RISK PROJECTIONS FOR EXPLORATION MISSIONS: UNCERTAINTY REDUCTION AND MITIGATION FRANCIS A.

CUCINOTTA 1, WALTER SCHIMMERLING2, JOHN W. WILSON3, LEIF E. PETERSON4, GAUTAM D. BADHWAR 1, PREMKUMAR B. SAGANTI1, AND JOHN F. DICELLO5 1NASA, Johnson Space Center, Houston. For calculations of space radiation tissue specific cancer risks, Eq.

(2) is used for the cancer incidence risk rate with the organ dose equivalent estimated using the NSCR model.The NASA QF depends on two physical parameters: particle .Because of the complex nature of the space radiation en- vironment (Durante and Cucinotta, ), both acute (i.e.

short- term risk of radiation sickness) and late (e.g. cancer) effects are possible. Acute radiation syndrome (ARS) can be caused by in- tense solar particle events (SPE) with crews unable to reach ad- equate shielding.The design tools increases fidelity by incorporating common spacecraft and user specified materials in the geometry description with ray-by-ray transport to minimize the uncertainties due to range-scaling of material thicknesses and material ordering.