The Effects of Solar Variability on Technology: Objectives of … · 2009-05-20 · 2001 IEEE...

2001 IEEE Aerospace Conference, Big Sky MT, March 10-17, 2001 1

The Effects of Solar Variability onTechnology: Objectives of NASA’sSpace Environment Testbed (SET)

Kenneth A. LaBel, Janet L. Barth, Cheryl J. Marshall -NASA GSFC

Dana Brewer - NASA HQBilly Kauffmann - NASA MSFC

Geoff Giffin - Superhighway SystemsPaul W. Marshall - Consultant


Outline

• What is Living with a Star (LWS)?• What is SET?• Technology Goals of SET• SET Concept• SET Flight Experiment Carrier Concept• Flight Experiment Scenarios: Examples

– Instrument Flight Validation

• Comments and Conclusion


What is LWS?


The Sun & Earth Are a Connected System

Variable Star Earth

Interacting• Magnetic fields• Plasmas• Energetic particles

Interacting• Magnetic fields• Atmosphere• Plasma• Energetic particles

Varying

• Radiation• Solar wind• Energetic particles

Interacting

• Solar wind• Energetic particles

QUESTIONS:

• How and why does the Sun vary?

• How do the Earth and planets respond?

• What are the impacts on humanity?


Scientific Understanding

EngineeringApplications Enabled

by LWS Science

Living With a Star (LWS):Science with Relevance

ApplicationsNear Earth

ApplicationsBeyond Earth

SET TechnologyDevelopment

SET TechnologyDevelopment

Implement LWSScience Missions &Theory & Modeling

Goal: Develop thescientificunderstanding toaddress theaspects of theConnected Sun-Earth system thataffect life andsociety

Implement SpaceEnvironment

Testbeds (SET)


Defines environment in the absence of the spacecraft

Theory & Modeling

Yearly Research

Opportunities

Science Missions

Gathers basic science data to achieve understanding

Partners Solar Sentinels

Ionospheric MappersRadiation Mappers

Solar Dynamics Observatory (SDO)

Sun Earth Connection (SEC) Science Theme

LWS Program

SEC Advisory Subcommittee (SECAS)

Defines environment

interaction with spacecraft

Partners

Space Environment

Testbeds(SET)

SET 3SET 2

SET 1

LWS Science Architecture Team (SAT)

SET Steering Committee

LWS Program Architecture


What is SET?


Living With a Star Space Environment Testbeds

• Collect data in space to validate the performance ofinstruments for LWS science missions & new spacetechnology

• Collect data in space to validate new & existing groundtest protocols for the effects of solar variability onemerging technologies & components

• Develop & validate engineering environment prediction& specification models, tools, & databases

• Improve the engineering approach to accommodateand/or mitigate the effects of solar variability onspacecraft design & operations

Scope

Approach

Objective

• Spacecraft hardware & design /operations tools whoseperformance changes with solar variability


Justification for the SET: Changes in theSystem Design Environment

• Demise of environment hardened market• Commercial demand for electronics• Short mission development times• Smaller, lighter spacecraft• More demanding mission requirements• Desire to operate in more severe environments• Consequences

– Use of commercial off the shelf (COTS) components– Use of emerging technologies– Higher environment specifications

• Result– Risk avoidance à Risk management– Accommodations in Design Phase à Accommodations in Flight– Capability is eroded with environment accommodation overhead– Precludes use of some new technologies


Technology Goals of SET


Technology Goals of SET

• Ground test and performance predictionimprovement

• Reduced design margins

• Environment-tolerant technology and mitigationstrategy validation

• Operation in harsh solar-variant environmentssuch as MEO

• Other goals exist such as improved environmentprotection for astronauts


Reliable Technologyfor

Space Systems

TechnologyDevelopment

GroundTest, Protocols,

and Models

On-orbitExperiments andModel Validation

Technology Triumvirate forInsertion Into Spaceflight


GroundTest

FlightTest

Mixed particlespecies

Combinedenvironment

effectsOmnidirectional

environment

Broad energyspectrum

Actual particle rates

Single particlesources

Individualenvironment

effectsUnidirectionalenvironment

Monoenergeticspectrum

Acceleratedparticle rates

(Multiple tests withvarying sources)

Actual conditions Simulated conditionsHow accurate is the

ground test in predicting Space Performance?

SET Goal: Improved GroundRadiation Test Protocols


EnvironmentalPrediction

SET Goal: Reduce Design Margins andUncertainty Factors


SET Concept

• SET Partners: Partners contribute to the successof the LWS/SET Program– Agree on objectives and requirements– Participate in all Program aspects

• NASA and its SET Partners support– A series of flight technology experiments– Data analysis of existing flight performance data– Development of a common carrier for flight experiments


Methods for Experiment TechnologyValidations in Space Science

• Methods are:– Experiments directly interface to host spacecraft as secondary payloads– Experiments interface to testbeds

• What is a testbed? Common support hardware & software to validate several experiments• Experiments include materials, components, cards, sensors, and subsystems

– Testbeds either retain permanent attachment in space (host spacecraft) or are jettisoned(piggyback)

Not NASA-funded experiment; partneringSET-funded experiment

Testbed

Experiments

Testbed

Host SpacecraftPrimary Spacecraft with Piggyback

Adapter


Appropriate Candidates for the Living With aStar (LWS) Space Environment Testbeds (SETs)

SET Space Flight Candidates:• Technology that requires space flight for performance

characterization or validation• Technology candidates applicable to more than one

mission or a LWS mission• Technology whose performance changes due to the effects

of solar variability– Performance changes cannot be minimized by changing the

spacecraft design

SET Data Analysis Candidates:• Data that describe performance variations in space in the

presence of a spacecraft that changes due to solarvariability


Three Options for Partnering• SET Partners: Partners contribute to the success of the

LWS/SET Program– Agree on objectives and requirements– Participate in all Program aspects

• SET Carrier Partners: Partners contribute to the success ofthe Carrier– Retain separate requirements & objectives– Obtain allocation of spacecraft resources to achieve

objectives

• Payload Partners: Partners contribute “payloads” inexchange for on-orbit operation, launch, & data return– “Payload” includes ground test data if appropriate, on-orbit

data after reduction, & funding for integration and on-orbitoperations

• Variations in definitions of “payloads” are negotiable; “funding”can include in-kind exchanges


SET Flight Experiment CarrierConcept


SET Carrier - Where it fits

Non-SETPayloads

Satellite(Host)

SETExperiment

Carrier

Card-levelExperiment

Box-levelExperiment

LaunchVehicle


Representative SET Carrier Platforms


CarrierFacilities

SET Carrier Facilities

HousekeepingTelemetryCollection

ExperimentInterface

andMechanical

Platform

CollateralEnvironment

Measurements

DataProcessing and

Storage

Power SignalConditioning

Host S/CInterface


Flight Experiment Scenarios


Generic SET Technology Flowdown

Flight Validationof Technology

Flight Validationof Protocol

Flight Validationof Model/Tool

Ground Test ProtocolDevelopment


Technology ApplicationModel/EngineeringTool Development

Not SET Funded


Example: SiGe Technology Flowdown forSET - Technology Development


CEB

SiGe

DARPA and DoD have invested >$100M inthe development of SiGe Technology at IBM and elsewhere

• High-speed (approaching 100 Ghz)• Low noise• Low power consumption• Mixed signal capabilities• Standard Si compatible

NASA has keen interests• RF/Microwave/Communications• Mixed signal/System-on-a-chip• Ultra-high speed data transfer• Low-noise instrumentation• Potential extreme temperature applications


Example: SiGe Technology Flowdown forSET - Ground Test



SiGe Damage Data

The NASA Electronic Parts andPackaging (NEPP) Program along withDoD is in process of developingtechnology radiation sensitivity models

• Dose and damage tests have been performed with encouraging results• Preliminary single event data indicates a single event sensitivity*. FY01/02 plans focus on single event testing, modeling, and hardening• Test protocols available NLT FY03• NEPP also supporting reliability modeling of SiGe• Total investment >>$1M

* Single event environment is solar-modulatedProton irradiation test fixture


Example: SiGe Technology Flowdown forSET - Tools




Upon completion of ground testprotocol development,predictive performance toolsare greatly desired

• Modules for single event upset (SEU) for industry standard software (CREME 96)

• SEU-hardened cell library

SiGe Charge Collection Modeling


Example: Detector Technology Flowdown for SET- Technology Development


Detector technologies have been criticalto increased science knowledge for NASA

• Examples include Hubble Space Telescope’s charge coupled device (CCD) based instruments. Newer Si-based CCDs have scaled geometries allowing better image resolution.

• Wavelengths of interest include visible, x-ray, ultraviolet, and infrared

• Engineering applications include star trackers and star cameras

Technology limitation: performance in the space radiation environment

• DoD and NASA have invested in hardened sensor technologies for space utilization (p-channel CCDs and monolithic advanced pixel sensors (APS))

CCD Messier image


Example: Detector Technology Flowdownfor SET - Ground Test



While many detectors and detector-based instruments have been testedand calibrated prior to flight, there isno community-wide test standard

• NASA (NEPP) and DoD have begun collaborations which will lead to a “lessons learned” overview of ground testing.• In some areas, test data is limited or old. A relevant example is ground test data for determining cosmic ray rejection in images.

Ground tests of newer technologies may or maynot be able to leverage on older data

• Flight performance has rarely matched predicted models (AXAF, HST, SOHO, et al)• Shortcomings may be due to technology or shielding models or mapping of the flight environment to the ground test environment

Schematic representation of an advanced pixel sensor


Example: Detector Technology Flowdownfor SET - Tools




Upon completion of ground testprotocol development,predictive performance toolsare greatly desired

Advanced column sensor array

SOHO/LASCO coronographspotted with solar particlesduring July 14, 2000 event

• Modules for imagedegradation due toradiation damage

• Methods for cosmicray rejection

• Methods for damagehardening


Example: Spacecraft Charging TechnologyFlowdown for SET - Technology Development


Spacecraft charging may be the dominantcause of anomalies in the natural spaceenvironment

• Deep dielectric charging• Surface charging

Symptoms include• Distortion in science measurements• Arcing• Increased contamination risk• Reduced spacecraft power• Anomalies in electronics similar to single particle induced effects

Technologies of interest• Materials interaction with plasma/ electrons• NASA, DoD and commercial aerospace all have programs in this arena

Spacecraft flying in high electronpopulations can no longer affordto be protected by Faraday cages

GOES 8 MUNIN 7 - 6 kg


Example: Spacecraft Charging TechnologyFlowdown for SET - Ground Test



Ground tests on materials aretypically performed with monoenergeticelectrons per ASTM standards

• Correlation of flight to ground has very limited statistics• Correlation of plasma environment with in-situ measurements is limited• For example: knowledge of solar array area affected by arcing in flight is limited

Complex spacecraft geometries anddynamic solar-modulated environmentcomplicate accuracy of ground testingand effectiveness of charging mitigation

Terrestrial lightning strikereminiscent of a solar array arc


Example: Spacecraft Charging TechnologyFlowdown for SET - Tools




Current tools for design arelimited

• NASCAP 2K and spacecraft charging handbook are not fully validated or complete tools

New validated tools are highlydesired

• Dynamic tools• Novel charge mitigation techniques

AFRL’s CEASE Instrument

Material potentialversus electron temperature


Instrument Flowdown

TechnologyDevelopmentfor Instrument

InstrumentDevelopment

Ground TestCalibration &Qualification

Flight Validation &Calibration

of Instrument

Specific technologies ininstruments may beapplicable to SET FlightValidation ofTechnologies

Non-SET Funded

SET Funded


Comments and Conclusion

• SET is:

– A series of flight technology experiments

• Data is correlated with environment sensors

– Data analysis of technology in-flight performance

• Partnering is very flexible

– Opportunities exist on many levels

• First testbed is planned for late FY03/early FY04

• FY01 NASA Research Announcement (NRA) release in earlyspring ‘01 for experiments and environment sensors


Acknowledgements

• Martha O’Bryan for her support in developingthis talk

• Christina Seidleck for her software support


Points of Contact for Partnering

• Dana Brewer – NASA/HQ– 202-358-1678– [email protected]

• Janet Barth – NASA/GSFC– 301-286-8046– [email protected]

• Ken LaBel – NASA/GSFC– 301-286-9936– [email protected]

• Website:– http://sec.gsfc.nasa.gov/lws_set.htm

The Effects of Solar Variability on Technology: Objectives of … · 2009-05-20 · 2001 IEEE...

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