# Presentation: 316017

## 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

**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

****** ****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

**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

**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

**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

## 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.

## Dependence on Solar Activity

**Low Inclination - HST Orbit**

**CREME96**

## SAMPEX – Iron

***Provided by B. Giles, July 2002***

## 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

***John C. Isaacs, Space Telescope Science Institute****** ***

## 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

***Koons et al., Aerospace Technical Report, 1999***

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

**CREDO on MPTB – QinetiQ (Formerly DERA)**

## 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?

**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

## 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

**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)

**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)

## Spacecraft Charging

## 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

**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

**Linear Energy Transfer (LET) Spectra**

## Anomaly Review

**Anomaly Analysis**
**Solar Storm – November 3-7, 2001**
**GOES showed increase in protons**
**Heavy ions? - Need high energy and LET > 2 MeV-cm****2****/mg**
**CREDO/MPTB measured increase in  0.1 < LET < 10 MeV-cm****2****/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

## 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

_**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**