# Presentation: 252045

## GROUP F EFFECTS ON INSTRUMENTS, SPACECRAFT & COMMUNICATIONS

- Eamonn Daly and Jim Adams

## Effects Considered

-  **Single Event Effects in Electronics **
** ****Total Radiation Dose to Components**
** ****Single Event Effects in Sensors**
** ****Radiation Damage to Sensors including activation**
** ****Radiation Damage to Solar cells**
** ****Space Weather Effects on Communications**
** ****Electrostatic Charging**** **

## Requirements for Models Radiation Belts

- Replacement of AE8, AP8 (static models)
- This is needed for:
- SEE (inner belt protons)
- Total dose (outer belt electron long term averages)
- (Deep) electrostatic charging (outer belt short term variations)
- Sensor background (short and long term variations)
- Models must provide history of variations on various timescales
- solar cycle, months, days, hours, minutes
- Example: POLE model (electrons at GEO)

## Requirements for Models Plasma

- Spacecraft charging environments
- short term variations
- e.g. Mars mission architecture foresees the transit vehicle parked at GEO.

## Requirements for ModelsSPEs

- Need a debate on which are the most appropriate models and methods, involving all disciplines
- Approaches include:
- 4 x August72
- ‘Oct 89
- Feb ‘56
- Risk-based models
- Data-based analysis (long records)
- Need heavy ion models (flux and fluence energy spectra)
- ISO Standards activities need more community involvement
- Need helio-radial dependence of flux and fluence

## Requirements for Models Space Weather

- Nowcast more important (and expected to be more reliable) than forecast;
- Prediction of SPE occurrence and expected time profile (at vehicle location);
- All clear (resume normal operations);
- Autonomous/crew situational awareness and operation of vehicles;
- Utilization of long-term space weather datasets for design/modeling/operations
- Quality control
- Validation
- Synthesis into design tools

## Single Event Effects Models

- Replace CREME96 (CREME is a tool combining GCR, SEP and error rate prediction)
- Improve solar particle models
- Update GCR model including correct solar cycle modulation of composition
- SEE prediction method improvements, addressing:
- geometry complexity
- decreasing feature size
- track effects
- single event transient effects
- Implement physics-based modeling
- particle interactions + device physics

## Testing

- We expect a large demand due to the use of COTS parts & systems
- Exisiting Facilities:
- Tandem 20m @ 300MeV (too low, need de-lidding and vacuum, but fast to use)
- Berkley 88 inch (Aerospace): better range but still need de-lidding, vacuum;
- TexA&M K1200; higher range (need de-lidding and thinning)
- Mich State 2 x K1200 ; no de-lidding necessary (50-200MeV/nuc); more costly
- NASA (NSRL) Ion Beam Facility Brookhaven (50-200MeV/nuc); Access policies are oriented toward scientific investigators, e.g.:
- Peer reviewed life _sciences_ proposals
- Preliminary data for intended proposers to NASA calls
- Non-life-science NASA experiments (not charged for small amounts)
- Some new proposal process or executive decision is needed for engineers to gain effective access.
- Quality Control
_**Major Issue**_: engineering _tests _need to be implemented for Exploration Program

## Findings

- Availability of and access to adequate external accelerator beams needs to be assured though agreement with DOE
- Revision of the radiation effects prediction tools is needed
- Improved models of proton and heavy ion environments in SEPs are needed
- On-orbit testing is needed for critical system tests and model validation
- A suitable radiation environment monitor needs to be included on each NASA mission so radiation effects can be diagnosed.
- New tools will be needed for *forecasting* space environmental conditions on Mars missions
- NASA needs to ensure that the communities represented at this meeting continue to work together

## Backup Charts

## Solar activity can effect instrumentation, spacecraft and communications by:

- degrading **solar cells**
- affecting **electronics **primarily by single event effects caused by protons and heavy ions
- interfering with **sensors** by both direct ionization and activation of the sensor or surrounding materials
- direct ionization interferes with solid state cameras
- degrading optical and thermal control **surfaces**
**Activation** of gamma ray spectrometers

## Issues

- Critical systems
- Life support
- communications,
- Navigation and guidance (incl. launch)
- In-situ resource systems
- Lunar Infrastructure
- Communications, navigation, beacons
- Local environment measurements (instruments for geology)
- Technology Evolution
- Analysis and testing problems

## Points Discussed

- Missions
- LRO
- CEV
- Other lunar reconnaissance missions
- Infrastructure elements
- Mars missions
- Technologies
- COTS components
- FPGAs
- Testing
- Critical systems
- Technology trends
- Need for precursor technology missions
- Monitors and in-orbit test-beds
- Forecast vs. hardening

- Effects Review
- Total radiation dose to components
- Radiation damage to solar cells
- Radiation damage to sensors
- Single event effects in electronics
- Single-event effects in sensors
- Electrostatic charging
- Space weather effects on ionosphere/thermosphere
- Requirements for engineering models
- Radiation belts
- Magnetospheric plasma
- Solar energetic particles
- Cosmic rays
- Space weather
- SEE models

## Missions and Elements

- LRO (2008)
- Includes CRATER instrument
- Includes precise remote sensing of topology and composition (various spectrometry)
- GNC on board critical system
- “today’s” technology
- LRO 2-5? (2010-2016?)
- Landers with rover? Permanently shadowed craters;
- CEV
- CEV-mark 1 – manned but limited for ISS
- CEV-for lunar = same + polyethylene (will be left unmanned and operate autonomously 6 months)
- Partially re-used
- CEV variant for Mars crew transfer
- CEV-derived cargo carrier
- pressurized,
- unpressurized

- Lunar manned missions
- Parked in LEO for up to 1 month; 2 weeks on lunar surface;
- Lunar rover
- Lunar bases
- long-term or permanent
- long-term damage and system effects
- Surfaces damaged
- “Earth-moving” equipment
- Infrastructure elements
- further downstream (permanent?) – habitats, communications, navigation, power
- Mars missions
- 1998 reference mission
- Stored at GEO/high altitude; transfer by CEV;
- More complex architecture – more to go wrong
- Launchers – heavy launcher
- restartable upper stage – critical
- Diagnostic imaging

## Technologies

- Strategy for CEV will be to use proven technologies (2008 flight test CEV)
- But (for example)
- COTS components will be widespread
- FPGAs
- MEMS
- RTGs?
- Hard drives
- Systems on chips
- Multi-junction solar cells
- In many critical systems
- All imply needs for considerably improved methods for
- testing
- prediction
- hardening by design (& fault tolerant systems)

## Technology Trends

- Many more critical systems
- Increasingly difficult to test realistically
- Procurement of at unit level(GPS, laptops...)
- Component Issues
- Scaling
- 90nm – 65 nm – 45 nm (18mths) ...?
- Gb DRAMs;
- Low Voltage
- Speed multi GHz
- Materials: Cu tracks; oxides; *non-Si devices*;
- Packaging;
- Rad hard cmos; secondaries;
- Optoelectronics; mixed signal systems;

## Slide 17

## Needs for Precursor Missions, Test-beds and Monitoring

- Flight test complete critical systems in relevant orbits before undertaking (in particular) human Lunar (Mars) missions;
- Exploration test-bed program should follow the LWS SET and New Millennium programs;
- Monitors (at least simple sensors, dosimeters) should be flown on all spacecraft;

## Forecasts vs. Hardening

- Critical systems:
- Operate-through requirement (_harden_)
- Non-critical :
- Shut down to prevent damage
- Sensor safeing needed
- No critical actions during high background events
- Spurious signal handling
- Instrument closure
- Generally, the engineering approach is to harden systems against worst cases
- Exceptions always appear; late implementation of protective operational measures will inevitably occur

## Total Radiation Dose to Components

- Lunar missions
- Lunar delivery: radiation belts (fast vs. slow transits)
- Short-term state of radiation belt;
- Mars Missions
- R>1AU
- SPE helioradial variation models
- Elements parked for long periods in Earth orbit
- Generic Needs
- SPE risk models;
- Tools for component dose prediction

## Radiation Damage to Solar cells

- Lunar missions
- Lunar delivery: radiation belts (fast vs. slow transits)
- Short-term state of radiation belt;
- Mars Missions
- R>1AU
- SPE helioradial variation models
- Elements parked for long periods in Earth orbit
- Generic Needs
- SPE risk models;
- Tools for prediction in multi-junction cells

## Radiation Damage to Sensors

- Lunar missions
- Lunar delivery: radiation belts (fast vs. slow transits)
- Short-term state of radiation belt;
- Mars Missions
- R>1AU
- SPE helioradial variation models
- Elements parked for long periods in Earth orbit
- Generic Needs
- SPE risk models;
- Tools for prediction of sensor damage

## Single Event Effects in Sensors

- Lunar missions
- LEO/transit protons;
- GCR; SPE; Predictions;
- Mars Missions
- SPE helioradial variation models
- Predictions
- Elements parked for long periods in Earth orbit
- Generic Needs
- Event data;
- data-based analysis (non-extreme events);

## Single Event Effects in Electronics

- Lunar missions
- LEO/transit protons;
- GCR; SPE; Predictions;
- Mars Missions
- SPE helioradial variation models
-  Albedo n environment
- Predictions
- Elements parked for long periods in Earth orbit
- Generic Needs
- Event data; Energy spectra (not just LET)
- data-based analysis (non-extreme events);
- tools for modern devices

## Space Weather Effects on Ionosphere/Thermosphere

- Lunar missions
- Mars Missions
- Generic Needs
- Optical and other comms

## Electrostatic Charging

- Lunar missions
- Mars Missions
- Generic Needs
- Radiation belt transits;
- Dynamic models;
- Predictions;

## Neutron (SEE) Environments

- Heavily shielded elements will have relatively significant neutron flux;
- Neutron albedo models for Mars (incl. Atmosphere, regolith, sub-surface H2O);
- Current capabilities probably sufficient

## Requirements for Models GCR

- Not a strong requirement in this area
- Updates of energy spectra, composition and solar cycle variations based on ACE data
- H, He from other sources

## Testing

- Exisiting Facilities:
- Tandem 20um 300MeV @ (too low, need de-lidding and vacuum, but fast to use)
- Berkley 88 inch (Aerospace): better range but still need de-lidding, vacuum;
- TexA&M K1200; higher range (need de-lidding and thinning)
- Mich State 2 x K1200 ; no de-lidding necessary (50-200MeV/nuc); more costly
- NASA (NSRL) Ion Beam Facility Brookhaven
- Mono-energetic beams 50MeV -> few GeV/nuc;
- Representative for electronics (incl. appropriate LET spectrum)
- Simulated cosmic ray spectrum available in ~1 yr
- 34M$; 1200hr/yr; ~100 groups;
- European and Japanese groups within context of reciprocal agreements
- Priority (regular solicitations):
- Peer reviewed life _sciences_ proposals
- Preliminary data for intended proposers to NASA calls
- Parasitic experiments (no payment)
- Non-life-science NASA (not charged for small amounts)
- Quality Control
- “Mission Critical” type applications carefully scrutinized
_**Major Issue**_: engineering _tests _- need to be implemented for Exploration Program

## Main Findings

- NASA needs to ensure the availability of and access to adequate external particle beams for SEE testing;
- NASA needs to support revision of the radiation effects prediction tools;
- NASA needs to provide improved models of proton and heavy ion environments in SEPs;
- NASA needs to provide facilities for on-orbit testing, including critical system tests and model validation;
- NASA needs to provide new tools for *forecasting* space environmental conditions for the Mars mission;
- NASA needs to ensure that all communities involved continue to work together in this area;
- NASA needs to include the means of acquiring a minimum set of information on the space environment on each of its missions