barth cdaw

Spacecraft& InstrumentsDesign and Operations: 

Spacecraft & Instruments Design and Operations Janet L. Barth Kenneth A. LaBel NASA Goddard Space Flight Center Flight Electronics Branch 2002 LWS CDAW – Solar Particle Events

Outline: 

Outline Space Environment Effects Drivers for Space Weather Model Requirements SW Model Requirements Climate Models Event Archive Nowcasts Forecasts Focus areas for this week?

Natural Space Environments: 

Natural Space Environments  Degradation of materials  Thermal changes   Contamination  Excitation  Spacecraft glow  Drag   Charging/Discharging  Radiation damage   Radiation induced data loss and interference 

LWS Science Support for Spacecraft: 

LWS Science Support for Spacecraft Designers & Operators* Models to mitigate the effects of solar variability on technologies *NASA Missions, NASA Human Support Systems, DoD, Spacecraft Industry, Aircraft Industry Science Missions TMDA Program Perform Research on the Environment Space Environment Testbeds Perform Research on System Response to the Environment Inputs for Environment Models (Predict space environment) Inputs for Interaction Models (Predict performance in space environment)

Sources for Environment Information: 

Sources for Environment Information European Space Agency/ESTEC Radiation Environment Monitoring Program On-line tool development – SPENVIS (BIRA with ESA support) NASA/Code R - Space Environment and Effects Program Space Environment Models CNES/TRAD Radiation Environment Monitoring Program Integrated tool development – OMERE (TRAD with CNES & ALCATEL support) NSSDC IMP-8 data NOAA GOES and TIROS Data Forecasts DoD - Microelectronics and Photonics Testbed (MPTB) LET Monitor & Dosimeters Technology experiments Living with a Star – Theory and Modeling Program Space environment models Living with a Star – Science Programs Improved measurements of high energy electrons and ions Understanding of Sun-Earth connections

Drivers for Spacecraft Design & Ops: 

Drivers for Spacecraft Design & Ops Small market for spacecraft components Driven by commercial demand for electronics More demanding mission requirements Imagers, on-board processing, data storage, etc. Short mission development times Can’t use long lead time custom designs Desire to operate in more severe environments MEO, long mission durations Smaller, lighter spacecraft Low power, reduced shielding

Risk Management for Missions: 

Risk Management for Missions Availability of appropriate space environment information has not kept pace with technology developments. Operations Avoid Risk Anomaly Resolution Reevaluate Risk Design Minimize Risk

Space Weather Model Requirements: 

Space Weather Model Requirements

Climate Models: 

Climate Models Purpose - minimize risk in spacecraft design phase Minimum requirements Represent long-term variation over the solar cycle with at least 1-month resolution Provide worst case estimates Provide confidence levels Broad energy spectra – high energies Radiation Belts Dynamics at GEO Validation of trapped particle models for MEO Long term variation of “slot region” filling Duration of slot region populations Solar particle cutoff latitudes, esp. for low inclination orbits Solar Particles Energies > 100 MeV Energy spectra and ion content Statistical distribution of energy spectra of events

ESP Model – Xapsos et al.: 

ESP Model – Xapsos et al.

Dependence on Solar Activity: 

Dependence on Solar Activity Low Inclination - HST Orbit CREME96

SAMPEX – Iron: 

SAMPEX – Iron Provided by B. Giles, July 2002

Event Archive: 

Event Archive Purpose – mission planning and operational guidelines Mission design phase - Understand impact of events on mission performance, e.g. degradation plans, mitigation requirements, band width requirements, estimation of loss of viewing time Post-anomaly resolution Minimum requirements At least one full solar cycle – not just solar active times Spatial coverage from interplanetary to low earth orbit Time profile of events Adequate energy range On-line accessibility with analysis tools Radiation belts SAMPEX protons & electrons SAMPEX ions for solar particle events Solar Particles Protons > 100 MeV Event spectra for heavier ions, IMP-8/U of Chicago, ACE, WIND

NGST Mission Design – GOES Protons: 

NGST Mission Design – GOES Protons John C. Isaacs, Space Telescope Science Institute

Nowcasts: 

Nowcasts Purpose - resolve anomalies Minimum requirements Spatial coverage from interplanetary to low earth orbit Time profile of event Adequate energy range Adequate ion composition information Specific to effect on technology Available quickly, on-line Radiation belts Need specifics as to location, time, energy spectra, etc. Detectors or modeling? Existing spacecraft are usually in the wrong place at the wrong time Models do not have capability at this time Detectors on spacecraft – LET, Dose, Simple particle counters Solar Particles GOES for protons, higher energy needed MPTB LET monitor for heavier ions (UK instrument so ESA SW page?)

Distribution of Spacecraft Anomaly Records: 

Distribution of Spacecraft Anomaly Records Koons et al., Aerospace Technical Report, 1999

LET Monitor– MAP Safehold on Nov. 5, 2001: 

LET Monitor– MAP Safehold on Nov. 5, 2001 CREDO on MPTB – QinetiQ (Formerly DERA)

Forecasts: 

Forecasts Purpose - protect investments, mission operations, and personnel scheduling Minimum requirements Spatial coverage from interplanetary to low earth orbit Level of severity Specific to effect on technology Maximum energy Ion composition Radiation belts Belt pumping Slot region filling Solar particles Forecasts of ion composition Maximum energy of ions Quiet times – location for near earth orbits

Focus areas for this week?: 

Focus areas for this week? Statistical distribution of ion spectra of SPEs Forecasts of ion content of SPEs Forecasts of maximum energy of SPEs Cutoff latitudes Ion penetration to low inclination orbits Connection between solar events and radiation belt activity Connection between activity indices and radiation belt flux levels New belt formation What is the statistical distribution of the duration? Can the duration be predicted? Maximum energy? Worst case flux levels?

Backups: 

Backups

Seastar - Single Event Upsets: 

Seastar - Single Event Upsets Single Event Upsets on Flight Data Recorder January 1 - December 25, 1999 – 705 km No science data lost COTS DRAM Technology

Total Ionizing Dose: 

Total Ionizing Dose Solar protons Trapped protons Trapped electrons Secondary Bremsstrahlung (high electron environments) Mission totals for end-of-life estimates Time profiles of accumulation for degradation planning Specification metric Dose-depth curves Spacecraft specific dose levels Contributing Particles Environment Spec.

Non-ionizing Dose(Displacement Damage Dose): 

Non-ionizing Dose (Displacement Damage Dose) Solar protons Trapped protons Trapped electrons Neutrons Secondary from shielding RTGs Mission totals for end of life estimates Time profiles of accumulation for degradation planning Specification metric Energy spectra Shielded or unshielded Contributing Particles Environment Spec.

Single Event Effects (SEEs): 

Single Event Effects (SEEs)

Spacecraft Charging: 

Spacecraft Charging

Anomaly on NASA’s MAP: 

Anomaly on NASA’s MAP Microwave Anisotropy Probe Launched on June 30, 2001 Operated normally at L2 for about 2 months MAP entered into a safehold condition on November 5, 2001. Caused by a reset on the spacecraft’s processor Suspected cause was a Single Event Transient (SET) on a voltage comparator (PM139) which caused a voltage dropout. MAP was restored to normal operation. Anomaly review

MAP – Mission Design: 

MAP – Mission Design Environment definition and parts screening Pre-launch testing showed that hits by single heavy ions induced voltage dropouts No rad-hard substitute was available Used climate model to predict rate– CREME96 1 SET/year predicted for GCR background 1 SET/October 1989 type event Design accommodation – SET on PM139?  Safehold Long term forecast Used event archive (GOES) to determine long term space weather forecast Mission assumed the level of risk Operational guidelines Based on “particle level” forecasting

Heavy Ion Climate Model - MAP: 

Heavy Ion Climate Model - MAP Linear Energy Transfer (LET) Spectra

Anomaly Review: 

Anomaly Review Anomaly Analysis Solar Storm – November 3-7, 2001 GOES showed increase in protons Heavy ions? - Need high energy and LET > 2 MeV-cm2/mg CREDO/MPTB measured increase in 0.1 < LET < 10 MeV-cm2/mg Updated guidelines Forecasting Reiterated operational guidelines to mission Shutting down 5 times/month is not acceptable to MAP mission Need heavy ion forecasting Working on cooperative agreement with QinetiQ to get LET monitor data LWS/SET funded analysis of CRRES LET data from Clemson U.

GOES Proton Instrument: 

GOES Proton Instrument

SW Lessons Learned on MAP: 

SW Lessons Learned on MAP Risk avoidance  Risk management Do SW accommodation in design phase Space Weather information is required in mission design through operations. Requirements for anomaly resolution are: Ground tests of components Climate models for estimates of rates Component response model Appropriate Nowcast information – LET Solar heavy ion information is inadequate Need range of events Need probability models Need LET monitors

Space Weather Model Characteristics: 

Space Weather Model Characteristics Design  Operations Easily integrated into application tools Input variables for non-researchers Stable Output appropriate for the application Ion resolution, adequate energy range and resolution, time resolution, spatial resolution Technology specific Small error bars  Design margins reduce science capability Validated