Mission Systems Overview

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Mission Overview Page 1 SDO Preliminary Design Review (PDR) – March 9-12, 2004 Mission Systems Overview John Ruffa SDO Mission Systems Engineer

description

Mission Systems Overview. John Ruffa SDO Mission Systems Engineer. SDO Mission Top-Level Overview. SDO spacecraft intended to carry a suite of solar observation instruments to monitor and downlink continuous, real time science data from the sun and distribute to Instrument analysis sites - PowerPoint PPT Presentation

Transcript of Mission Systems Overview

Page 1: Mission Systems Overview

Mission Overview Page 1SDO Preliminary Design Review (PDR) – March 9-12, 2004

Mission Systems Overview

John RuffaSDO Mission Systems Engineer

Page 2: Mission Systems Overview

Mission Overview Page 2SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Mission Top-Level Overview

• SDO spacecraft intended to carry a suite of solar observation instruments to monitor and downlink continuous, real time science data from the sun and distribute to Instrument analysis sites

– Geosynchronous orbit to allow continuous downlink line-of-sight to dedicated ground station for continuous downlink capability

– Observatory Operations via typical S-Band system

– Ka-band Science downlink required to meet anticipated ~130 Mbps science data rate (~300 Mbps final downlink symbol rate)

• Real time downlink with no on-board science storage envisioned• High speed data pipeline from ground station to instrument analysis sites

“Get to orbit, stay pointed at the Sun, pump the data back”

– Intended for 5 year Mission Life• Propellant provided for 10 year operational life

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Mission Overview Page 3SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Implementation Design Driver Overview

• High data volume, coupled with tight requirements on data loss and degradation• High data rate, data interruption & loss requirements are a significant driver to S/C, ground system, and

ops concepto Ka-band downlink selected to support bandwidth, high-volume data transfer from ground station to instrument SOCso Mission architecture designed to address data completeness reqso Mitigated by data capture budget, system design architecture, operations concept

• Geosynchronous orbit• Selected to support continuous data downlink capability

o Drives mass, launch vehicle, and propulsion issueso Places SDO in severe radiation environmento Mitigated by clear mass and prop budgets, ops concept, environments definition

• Long mission life (5 year requirement, 10 year goal)• Mission life drives mechanism reliability, radiation requirements, failure concerns

o Mitigated by life testing, redundancy, fault tolerance

• Instrument pointing and stability• Number of pointing, alignment, and stabilization issues that need to be addressed in order to meet

instrument requirementso Fine pointing, jitter characterization and compensation using instrument guide telescopeo Driven by mechanical deformation & thermal stability, S/C and instrument boresight alignment requirementso Mitigated by mechanical/thermal design, detailed alignment budget, pointing & jitter analysis and budget

Page 4: Mission Systems Overview

Mission Overview Page 4SDO Preliminary Design Review (PDR) – March 9-12, 2004

Geosynchronous Orbit Insertion• Once SDO placed in geosynchronous transfer orbit (GTO), orbit circularization propulsion system required to circularize to geosynchronous orbit

- Inclined GEO orbit selected to minimize eclipse interruptions, eliminate need for North-South stationkeeping and maximize launch vehicle capability

- Baseline launch and orbit circularization concept- Baseline launch vehicle- Delta IV or Atlas V 401 series

- Bi-propellant propulsion system selected to circularize orbit

~36,000 Km Geosynchronous orbit

~36,000 Km apogee

~36,000 Km

~36,000 Km

~300 Km perigee

MEO orbital range (~1,500-20,000 Km)

- Higher trapped proton environ.(greater chance of SEE)- Higher TID environment

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Mission Overview Page 5SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Eclipse Season• The proposed SDO geosynchronous orbit will result in two eclipse seasons with a variable

daily eclipse each day– The two eclipse seasons will occur twice a year due to the effects of the orbit geometry and the earth-sun

position– During each eclipse season (~23 days), SDO will move through the earth’s shadow- this shadow period will

grow to a maximum of ~72 minutes per day, then subside accordingly as the earth-sun geometry moves out of the SDO eclipse season

– Eclipse season effects:• Instrument-

o Interruption to SDO science collectiono Thermal impacts to instrument optical system due to eclipse

• Power- o Temporary loss of power from solar arrayso Battery sizing study includes eclipse impact

• Thermalo S/C thermal design considerations due to semi-annual eclipses

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Mission Overview Page 6SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Science Data Path Implementation & Flow

Ground StationData Storage

HMI/AIA

EVE

Observatory science data collection:- No Data recorder, dramatically easing overall system complexity & cost- Data loss allocations characterized in data capture budget meet instrument science requirements - BER allocation for Radiation SEE data loss

RF Link:- BER allocation in data capture budget

Ground station :- Data Distribution System (DDS) system provides 30 day temporary data storage; replaces Observatory recorder & eliminates complex recorder management of Observatory- Dual 30 day recorder allows for system anomalies & maintenance, as well as data storage for retransmission in event of SOC data loss or line outages

Data transmission to SOCs:- High speed data lines with 1.5x capability allows for retransmission of data to SOCs from 30 day DDS storage- Result is essentially “error free’ data transmission from DDS to SOCs

SOC data collection & analysis:- SOCs can request retransmission of science data from 30 day DDS over existing high speed data lines- Removes quick turn-around data evaluation, reducing SOC complexity and cost

Dual antenna sites (SDO dedicated):- Both antennas actively receiving & transferring data to DDS - Geographically diverse (3 miles) to address localized rain attenuation- Each antenna has 48 hr data buffer to avoid data loss in transferring data to ground station DDS- Dual antennas dramatically increase system reliability, remove need for more costly, higher reliability single antenna- remove need for quick turnaround maintenance to avoid prohibitive data loss in event of single antenna anomaly

NO PROCESSING OF SCIENCE DATA AT GROUND STATION-Dramatically eases complexity and cost of ground system-Allows “bent pipe” transfer of instrument science data to SOCs

ScienceCommunity

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Mission Overview Page 7SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Ground System Architecture10/21/03

Telemetry & Command(T&C)

SystemASIST / FEDS

Telemetry MonitoringCommand Management

HK Data Archival (DHDS)HK Level-0 Processing

Automated OperationsAnomaly detection

Flight DynamicsSystem

Orbit DeterminationManeuver PlanningProduct Generation

R/T Attitude DeterminationSensor/Actuator Calibration

SDO Mission Operations Center

HMI AIA JSOC(Stanford / LMSAL/

Palo Alto Ca.) EVE SOC(LASP /

Boulder Co.)

Acquisition Data

Observatory Commands

Observatory Housekeeping Telemetry

Tracking Data

Trending

Mission Planning& Scheduling

plan daily/periodic eventscreate engineering planGenerate Daily Loads

HMIScience Data

55Mbps

Station Status

Ka-Band:150 Mbps

Science Data

S-Band: TRK, Cmd & HK Tlm

Instrument Commands / Loads

Data DistributionSystem(Incl. 30-Day

Science Data Storage)

SDO Ground Site #1(White Sands)

Station Control

S-Bandground system

Ka-Bandground system

Ka Science Data

AIAScience Data

67Mbps

EVEScience Data

7 Mbps

R/T Housekeeping Telemetry

Science Planning and FDS Products

ExternalTracking Station

S-Band HK Tlm, TRK Data

AcquisitionData

DDS Control

DDS Status

Ground StationControl System

DDSControl System

SDO Ground Site #2(White Sands)

Ka-Band:150 Mbps

Science Data

R/T Housekeeping Telemetry

S-Band: TRK, Cmd & HK Tlm

Cmd & HK TlmS-Band: TRK,

Cmd(Includes 72-hr storage)

S-Bandground system

Ka-Bandground system

Alert NotificationSystem (ANS)

Flight Software Maintenance Lab

(FLATSAT)

Flight software loadsSimulated housekeeping telemetry

Memory dumpsSimulated commands

(Includes 48-hr storage)

Same Interfaces as Prime Ground Site

(Includes 72-hr storage)

(Includes 48-hr storage)

Status and Control

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Mission Overview Page 8SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Mission Phases Overview

Launch & Acquisition

Phase covering pre-launch configuration until Observatory is power-positive and pointing at the sun- Launch, separation, XPNDR power on, S/A deployment & RW power, sun acquisition

In-Orbit Checkout & Orbit

Circularization

Phase used during first weeks to checkout and calibrate Observatory-S/C modes verified, Ka-band deployed & verified, initial instrument checkout, calibration-Orbit circularization occurs during In-Orbit Checkout (IOC), with several burns needed at Apogee to raise orbit to GEO

Instrument Commissioning

Begins once SDO is on-station & Ka-Band downlink has been established. Phase lasts 60-90 days- Includes Instrument optical system checkout, calibration maneuvers, & commissioning activities

Science Mission Phase

Expected to be phase that mission stays in 99% of time once at GEO. Dominated by routine continuous instrument operations with few other operational activities planned- Science data transferred first to ground, then to SOCs, all on a continual basis (24/7)

Science Mission Phase Activities/Modes

Normal Mode Continuous routine uninterrupted instrument operations- Science data transferred first to ground, then to SOCs, all on a continual basis (24/7)

Periodic Calibrations/

Housekeeping

Interruptions in normal science phase needed for maintaining science quality- Instrument calibration maneuvers, Instrument alignment calibrations, HGA pointing calibration

Eclipse Principal Observatory req in this phase is to survive & minimize impact on science operations- Power storage and thermal (instrument optical bench and spacecraft) considerations

Stationkeeping & Momentum

Management

Required operations to keep SDO within its orbit “slot” & maintain Observatory angular momentum near zero- Planned to interrupt science once per month

Safehold & Emergency Modes

Several capabilities will exist on the Observatory for “safing” in the event of an anomaly- Fault detection/correction, autonomous safehold, 1553 safing notification, power subsystem load shedding

Disposal At end of mission, NASA requires disposal of SDO into an orbit that won’t interfere with other spacecraft- Increase altitude to >300 km above GEO orbit, Passivate energy sources

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Mission Overview Page 9SDO Preliminary Design Review (PDR) – March 9-12, 2004

Key Systems Engineering Functions

Requirements ID & Mgmt- Level 1 Reqs, Min Mission Reqs -Mostly Driven by Science- Top Down Hierarchy - Reqs Flow, Doc Tree, WBS, Product Structure, Team Org-Database utilized to track reqs flow, owner, verification

Architecture & Design- What the End Item looks like - Flight and Ground Elements, Hardware, Software Block Diagrams, Operations Team-Special Accommodations for Verification & Test - Design for testability

Operations Concept Development- How the End Item is used -Flight and Ground Elements, Hardware, Software, Operations Team- How the End Item can be verified & tested on the ground - Test Points, GSE impacts on Architecture and Design

The Three Major Functions Must Lead to a Balanced Design that is Consistent with Project Cost, Schedule and Risk

Project Objectives Met, Ready for Operations

Consistency is addressed repeatedly over the project life cycle- Phase A brings them into initial agreement - “Single Best System”

-Major Trades performed - Initial Reliability Analysis selects redundancy & back up approach -Initial Performance Predictions

- Phase B refines them and shows close agreement analytically - “Right System”- Phase C and D makes sure that they remain in agreement along with assuring design and build the “System Right”

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Mission Overview Page 10SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Requirements Flow Review• LWS Goals

• 7 Science Questions

• 5 Science Measurement Objectives• Science Measurement

Requirements (Full and Minimum Mission)• 3 Sets of Instrument Performance Reqs

(Full & Minimum Performance Reqs)

• Mission Requirements (MRD)

• Instrument and Subsystem Requirements

• Lower Level Requirements

Level 1 Requirements

Level 2 Requirements

SDO Science Definition Team Report

Level 3 Requirements

Lower Level Requirements

ScienceInvestigation Objectives

Requirements Flow

AnalysisAppendix A to the LWS Program Plan

• LWS Goals LWS Definition Team Report(s)

• 4 Science ObjectivesAIAEVE

HMI

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Mission Overview Page 11SDO Preliminary Design Review (PDR) – March 9-12, 2004

1. Solar Cycle Measurements: Make measurements over a significant portion of the solar cycle to capture the solar variations that may exist in different time periods of a solar cycle. ALL

2. Spectral Irradiance Measurements: Measure the extreme ultraviolet spectral irradiance of the Sun at a rapid cadence. EVE

3. Dopplergrams. Measure the Doppler shifts due to oscillation velocities over the entire visible disk. HMI

4. Longitudinal & Vector Magnetic Field Measurements. Make high-resolution measurements of the longitudinal and vector magnetic field over the entire visible disk. HMI

5. Atmospheric Images. Make images of the chromosphere and inner corona at several temperatures at a rapid cadence. AIA

The following measurements are necessary to answer the seven SDO Science Questions and will be performed by the three SDO investigations:

5 SDO Measurement Objectives

Each of these Measurement Objectives are identified within the Level 1 Requirements document along with Full & Minimum Mission performance levels

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Mission Overview Page 12SDO Preliminary Design Review (PDR) – March 9-12, 2004

Evaluating Mission Success

SDO's success criteria for mission performance are defined in the SDO Level 1 requirements: - FULL SUCCESS:

• 22 72-day intervals• Full success performance for all three investigations

• Full instrument science performance requirements detailed in SDO Science Overview presentation

- MINIMUM SUCCESS: • 11 72-day intervals • Minimum success performance for any two of three investigations

• Minimum instrument science performance requirements detailed in SDO Science Overview presentation

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Mission Overview Page 13SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Requirements Tree

Program Data Management Plan

(SDO Science Data)

EVE Instrument Specification

and ICD (2 Docs)

Mission Requirements

(MRD)

Level 1Requirements

HMI Instrument Specification

and ICD (2 Docs)

AIA Instrument Specification

and ICD (2 Docs)

Cross CuttingMAR, Elec Systems,

Environment, Contamination, etc

Operations Concept Document

Subsystem Requirements

Component Requirements

Technical Resources

(Mass, Power, etc)

Level 1 Reqs

Level 2 Reqs

Level 3 Reqs

(Appendix A to the LWS Program Plan)

(SDO Mission Reqs Doc [MRD], etc)

Ground System Requirements

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Mission Overview Page 14SDO Preliminary Design Review (PDR) – March 9-12, 2004

Mission Requirements Document (MRD) Hierarchy

5.0 Ground Segment Requirements- 5.1 Integration & Test (I&T)

- 5.1.1 High Rate Science GSE- 5.1.2 Low Rate GSE

- 5.2 Ground Station Implementation- 5.2.1 Dedicated Site Requirements- 5.2.2 Ancillary Site Requirements- 5.2.3 Commanding- 5.2.4 Housekeeping Telemetry- 5.2.5 Tracking- 5.2.6 Science Telemetry

- 5.3 Mission Operations Center (MOC)- 5.3.1 Command & Telemetry Functions- 5.3.2 Data Products

- 5.4 Science Operations Center (SOC)- 5.4.1 Ops- 5.4.2 Archive- 5.4.3 Data Products- 5.4.4 Science Data Acceptance

1.0 Science Requirements- 1.1 Science Observations- 1.2 Data Capture & Completeness- 1.3 Angular Resolution & Coverage- 1.4 Spectral Resolution & Wavelength Range- 1.5 Precision, Accuracy, & Dynamic Range- 1.6 Cadence

2.0 Mission Implementation- 2.1 Orbit- 2.2 Mission Life- 2.3 Environment- 2.4 Launch Vehicle (LV)- 2.5 Mission Implementation/Ops Concept- 2.6 Standard Spacecraft Services- 2.7 Development Approach

3.0 Instrument Requirements- 3.1 EVE

- 3.1.1 Alignment & Stability- 3.1.2 Spectral Resolution- 3.1.3 Timing- 3.1.4 Data Completeness- 3.1.5 Interface Reqs

- 3.2 HMI- 3.2.1 Alignment & Jitter- 3.2.2 Angular Resolution- 3.2.3 Timing- 3.2.4 Data Completeness- 3.2.5 Interface Reqs

- 3.3 AIA- 3.3.1 Alignment & Jitter- 3.3.2 Angular Resolution- 3.3.3 Timing- 3.3.4 Data Completeness- 3.3.5 Interface Reqs- 3.3.6 Dynamic Range

4.0 Spacecraft Requirements- 4.1 Structural/Thermal

- 4.1.1 LV Accom.- 4.1.2 S/C & Instr Accom.- 4.1.3 Thermal Monitoring & Control- 4.1.4 Instr. Optical Bench

- 4.2 Attitude Control & Determination- 4.2.1 Acquisition- 4.2.2 Pointing Knowledge- 4.2.3 Attitude Control & Stability- 4.2.4 Propulsion & Delta-V- 4.2.5 Momentum Management- 4.2.6 Safehold

- 4.3 Power- 4.3.1 Power Generation- 4.3.2 Power Storage- 4.3.3 Power Distribution- 4.3.4 Load Shedding- 4.3.5 Constraints

- 4.4 Comm & Data System- 4.4.1 S-Band Communication- 4.4.2 Ka-Band Communication- 4.4.3 Data System Functions

- 4.5 HGA Assembly- 4.5.1 Operation, Pointing, & Stability

- 4.6 Deployment Actuation & Verification- 4.6.1 Solar Array Deploy & Verif.- 4.6.2 HGA Deployment & Verif.

MRD

Requirements are organized in a hierarchy:

- Top level mission concept originates from Level 1 science requirements and defines top-level system requirements that apply to all mission elements

- Further concept definition is then based on this top-level concept and provides more detailed information on the specifics of the implementation

Level 1 Reqs

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Mission Overview Page 15SDO Preliminary Design Review (PDR) – March 9-12, 2004

Level 1 Requirements Flow/Traceability to Level 2

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Mission Overview Page 16SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Requirements • Level 1 Science Requirements

– Captured in the Appendix A to LWS Program Plan– Clearly addresses the Science objectives and measurements, full and minimum mission requirements

• Level 2 mission requirements captured in the Mission Requirements Document (MRD)– Level 2 requirements show clear flowdown and traceability from Level 1 Science requirements– Requirements properly and clearly allocated to specific subsystems– Detailed review process: SDO Systems Requirements Retreat (SRR), SRR/SCR, & MRD CM baseline– Other cross-cutting documents also identified as source of Level 2 requirements (MAR, Electrical Spec,

Environmental Verification reqs, etc)

• Derivation of Level 3 reqs as part of preliminary design & PDR preparation process– Subsystem requirements required to be submitted for CM baseline review by subsystem PDRs– Requirements show clear traceability to higher level reqs (MRD or other reqs documents) – Detailed requirements review as part of subsystem PDR process– Subsystem Level 3 requirements reviewed and baselined under CM prior to Mission PDR

• Requirements status– Level 1- Ready for signature by GSFC & NASA HQ as Appendix to LWS Program Plan– Level 2- Baselined and under SDO CM– Level 3- Majority baselined and under SDO CM, remainder in CM process– ICDs- In process

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Mission Overview Page 17SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Reqs Traceability/Verification Process

• All SDO requirements documents are included in the SDO document tree• All SDO requirements documents clearly identified, along with owner and due date

• Traceability– Each requirements document (Level 2 and lower) includes a requirements matrix with the following fields for

requirements traceability:o Requirement description and rationaleo Requirements allocation (or assignment)o Requirements traceability (“Trace From”)

• Provides traceability of requirements down from Level 1 through Level 2 (MRD or other cross-cutting documents) and lower

• Verification– Requirements documents also include verification matrix columns alongside the reqs entries

o CCR # - Documents by configuration change request any change to requiremento Verification Lead- Identifies individual or group responsible for leading and closing verification efforto Verification Status- Current status of verification efforto Verification Data- Points to data source where detailed verification information is containedo Signoff- Indicates project and systems team acceptance and signoff of verification effort

• Each requirements document owner is responsible (with systems oversight) to make sure that each requirements is adequately verified and signed off as part of the systems verification process

o Verification fields clearly delineate requirements signoff responsibility within documents

– DOORS database used as supplementary tool to trace reqs flow and track verification• Currently continuing the process of entering Level 3 reqs into DOORs

o MRD already entered into DOORS; Subsystem reqs being entered into system as they are completed and reviewed

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Mission Overview Page 18SDO Preliminary Design Review (PDR) – March 9-12, 2004

• Radiation - Total Dose and SEE464-SYS-ANYS-0010  Radiation Analysis for the Solar Dynamics Observatory

• Describes the environment, analysis method and results for the environment and preliminary Ray Trace results for certain selected areas of the Observatory

464-ELEC-SPEC-0004 Electrical Systems Specification• Documents the TID and SEE Requirements

• Thermal464-THM-REQ-0018  SDO Thermal Control Subsystem Requirements Specification

• Mechanical464-MECH-REQ-0007  Solar Dynamics Observatory (SDO) Structural Analysis and Test

Requirements

• Contamination464-SYS-PLAN-0002  Solar Dynamics Observatory (SDO) Contamination Control Plan

• Micrometeoroid and Orbital Debris No Special Environment Requirements

• Atomic Oxygen No Special Requirements for GEO orbit or short <30 Day transfer orbit

• Disturbances (Atmospheric drag, gravity gradient, solar pressure)464-ACS-REQ-0024  SDO Attitude Control Subsystem (ACS) Requirements

SDO Environments

464-ELEC-SPEC-0004 Electrical Systems Specification

•Documents the Requirements necessary to mitigate threats 464-SYS-REQ-0002 

Solar Dynamics Observatory (SDO) Project Environmental Verification Requirements

• Radiation - Charging Surface and Internal Requirements to mitigate ESD threats

• RF Exposure Pad, Launch and Orbit RF Environment

• Magnetic Orbital Environment and Observatory Generated

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Mission Overview Page 19SDO Preliminary Design Review (PDR) – March 9-12, 2004

Radiation - Total Dose and SEE

Radiation Effect Radiation Requirement ApproachTotal Dose (TID) 40 Krad behind 200 mil Al Acceptable with added shielding per Table 3-7.

Single Event Latchup (SEL) > 100 MeV-cm2/ Acceptable parts selection.

LETth > 37 MeV-cm2/mg Acceptable parts selection.

Single Event Upset (SEU) LETth < 37 MeV-cm2/mg

May be acceptable in lieu of SEU rates and effectsanalysis for the subsystem or SEU mitigationmethods, such as EDAC.

Dose-Depth Curve for GEO

10 Š

4

10 0

10 1

10 2

10 3

10 4

10 5

0 100 200 300 400 500 600 700 800 900 1000Aluminum Shield Thickness (mils)

Dos

e (k

rad-

Si /

5 yr

s)

Trapped ElectronsSolar protonsTotal

Approx 40K Rad behind 200 mil Al including 2x RDM

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Mission Overview Page 20SDO Preliminary Design Review (PDR) – March 9-12, 2004

Radiation Total Dose PredictionsRadiation total dose predictions based on recent ray

trace update with following assumptions– Spacecraft walls for the propulsion and spacecraft bus

modules are 40 mil thick aluminum.– Spacecraft walls for the instrument module are 40 mil

thick graphite composite material.– The size of the bus top deck hole is 45 inches across.– The propulsion module baseplate has 73.5 kg of mass

distributed over the 10 cm thick structure– Fuel tanks are empty & have 40 mil thick titanium walls.– All boxes have 100 mil thick aluminum walls.– Doses inside each box are calculated at the center

point.– The TID requirements include a 2 krad(Si) dose resulting

from a top level analysis of the GTO.– The TID requirements are for the required 5-year

mission in geosynchronous orbit.– The TID requirements include a factor of 2 margin.

***AIA & HMI preliminary radiation estimates shown, with TID analysis to confirm levels to be completed after PDR

– CCDs are shielded with 0.6 in. (1.5 cm) Aluminum equivalent (4-pi steradians)

– Optics Package electronics and Camera Electronics Boxes are shielded with 0.2 in. (0.5 cm) Al equivalent

– CCDs are cooled (to approximately -75 C) to mitigate the loss of charge transfer efficiency that is caused by radiation damage

Component Dose Requirement in Krad(Si): ACE Box 1 6.6

ACE Box 2 7.3

AEB (AIA Elec Box) 9.1

C&DH Box 1 6.8

C&DH Box 2 7.2

Gimbal Control Box 7.6

HEB (HMI Elec Box) 7.2

IRU Box 1 7.4

IRU Box 2 6.9

IRU Box 3 6.8

Ka Transmitter Box 1 11.4

Ka Transmitter Box 2 11.3

PSE Box 8.2

S-Band XPNDR Box 1 6.9

S-Band XPNDR Box 2 6.6

EEB (EVE Elec Box) 30.8

RWs 2.7

RW Electronics Boxes 2.5

EVE Instrument 3.5 (CCDs) 4.4 (ESP)

AIA Instrument *** 8 (CCDs) 24 (Optic pkg/ Camera Elec)

HMI Instrument *** 8 (CCDs) 24 (Optic pkg/ Camera Elec)

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Mission Overview Page 21SDO Preliminary Design Review (PDR) – March 9-12, 2004

Other Environments

• Charging requirements (464-ELEC-SPEC-0004 Section 3.7)

– External Charging: Surfaces charge then discharge to space or other parts of spacecrafto Designate Sun Side surface to bleed off charge accumulated by spacecraft portion shaded from the

sun.o External surfaces (>6 cm2) shall be conductive (<109 Ohm/Sq) and grounded to the observatory

structureo Unavoidable dielectrics accepted by waiver only

• Solar array substrate insulator, some tape, etc

– Internal Charging: Isolated conductive elements charges (floating conductors) and then discharges; Insulator charges and then discharges

o Mitigated by shielding to reduce internal charge rateo Control via other methods if shielding reqs not met

• Filter circuitry, exterior conductive surface coating, EMI shielding, conductive barrier, etc• Detailed in Section 3.7.3 of Electrical Spec

o No Floating conductors

– Addressed in Electrical Systems portion of PDR presentation

• Contamination (464-SYS-PLAN-0002)

– Addressed in contamination portion of PDR presentation

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Mission Overview Page 22SDO Preliminary Design Review (PDR) – March 9-12, 2004

Units Policy• NASA Units Policy guidance in NASA NPD 8010.2C

– “Use of the Metric System of Measurement in NASA Programs”• Adopt metric measurements as preferred system of weights and measures• Permit controlled use of hybrid units where full implementation of metric system is not feasible

• Policy documented in the SEMP– Flight & Ground Operational Software use Metric units (includes Flight operational products & deliverables,

such as algorithms and analysis)• Rationale: Limits opportunity for error in system with highly complex verification process; difficult to find flight units errors prior

to flight; various combinations of components & parameters may not be completely exercised or tested

– ICDs use metric units with English equivalent where necessary (typical for some mechanical items and Launch Vehicle)

• Areas that are more easily verified via ground inspection, assembly, testing prior to flight

– Manufacturing drawings can be English to enable use of US manufacturing facilities– Identify where Metric units are not used per NASA NPD 8010.2C.

• The plan for the prevention of misapplication of units is documented in the SEMP and implemented/tracked by the Systems Engineering team

– Identify categories where units error could result in loss of mission (ICDs, drawings, analysis, models, etc)• Identify in each subsystem where units error could cause mission loss

– Decide and document areas where ground verification and testing may not catch units error• Reviews, inspections, tests; Identify areas where ground testing might not catch errors where English units are misapplied

– Track the defenses against misapplication of units; Correct identified potential mission critical units errors• Utilize spreadsheet or database to record and track items

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Mission Overview Page 23SDO Preliminary Design Review (PDR) – March 9-12, 2004

Systems Engineering PlanningSDO Systems Engineering Management Plan acts as guiding document for System Engineering

functions throughout the various mission lifecycle phases- SDO SEMP (464-SYS-PLAN-0006)

SDO SEMP Completed, reviewed by the Team and GSFC Systems Engineering Office, baselined in SDO CM system as configured document

• Practical Definition of “Who” performs the Functions• Especially important to delineate responsibilities when functions are spread out among multiple partners

or contracts

• Describes a plan for “How” and “When” the Functions are done• “How” part should address the technique or mechanism for accomplishing the work and how various

interested parties will communicate

• Includes an Organization Chart with Job Description and Assignment• Details sources of communication among Observatory team

o Regular meetings between system team, with project mgmt, subsystems, instrumentso Website for collection/dissemination of project documents and analysiso Etc.

• Includes schedule for Systems Engineering activities & the resources required.• Not intended to contain boiler plate for general Systems Engineering, but is intended to

define specifics for the subject Project

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Mission Overview Page 24SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Systems Team Peer ReviewSDO Systems Team Peer Review held 12/2/03

– Intended as an independent review of the SDO systems engineering approach and processes by the GSFC Systems Engineering organization

• Review goals and Review Team Charter:– SDO System Engineering Process

• Review of the processes and approach used in the development and implementation of the SDO Mission o Are the appropriate system engineering functions clearly identified and addressed?o Are adequate processes planned to address all of the major system engineering functions required throughout the

complete developmental lifecycle?o Is the implementation of system engineering functions properly identified throughout the lifecycle phases so as to guide

the proper sequencing of work and catch problems and issues at an early enough stage to minimize development impacts?

o Does the SDO Systems Engineering approach adequately follow the intent and guidance of GPG 7120.5, Systems Engineering?

– SDO System Engineering Design Implementation• Review of the SDO implementation design concept

o Is there a clear flowdown of requirements to define the system and meet the mission objectives?o Does the overall implementation design reasonably balance the system requirements, architecture design, and

operations concept into a cohesive whole that meets the mission objectives?o Are there any significant implementation suggestions, experience bases, or lessons-learned that could add to the SDO

system implementation

• Review summary and actions:– Review team pleased with the SDO implementation approach and processes

• “…review team unanimously and strongly endorses both the systems engineering process and the mission design implementation that were presented at the review.”

– 9 RFAs generated, all in process of being addressed and closed– Systems Engineering Peer Review package, Review teams summary and comments, and RFA list available

for review

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Mission Overview Page 25SDO Preliminary Design Review (PDR) – March 9-12, 2004

Systems Engineering Lifecycle

• SDO development effort follows the phased development approach to conceive, develop the mission implementation concept, implement, verify and test, and operate the SDO mission

– Various development functions are allocated to different phases of the mission lifecycle in order to accomplish system development tasks in the proper order

– The Life Cycle Phases defines the work and progression gates to the next development step– Uses schedules and milestones to guide the proper sequencing of work

• The follow charts address the current phases of the Systems Engineering lifecycle by detailing the specific SDO implementation activities planned for each phase

– Documented in the SDO SEMP (464-SYS-PLAN-0006, Section 3.3)– Lifecycle activities planned to be updated in the SEMP at the end of each development phase as part of

planning for the next phase

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Mission Overview Page 26SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Phase B ActivitiesSystem Definition - Phase B Status

Understanding the Objectives

- Level 1 Science Reqs competed & signed off by NASA HQ; Includes minimum mission reqs- Track any changes to Level 1 reqs (changes req NASA HQ approval)

- Level 1 reqs updated & incorporated in Appendix to LWS Program Plan & ready for signoff

Operations Concept Development

- Refine SDO Mission Phases definitions and SDO Operation Concept Document - Mission Phases updated & Mission timeline added; SDO Ops Concept Document baselined under SDO CM

Architecture & Design Development

- CM block diagram of SDO architecture design concept- Begin preliminary system and subsystem design process- Begin conceptual breadboard design process; use conceptual breadboards as initial testbeds and for initial interface testing across subsystems for risk reduction

- Prelim Architecture baselined by various subsystem specs; preliminary design process underway; BBs in process for functional design verification

Requirements Identification &

Management

- Define draft Level 2 MRD reqs & demonstrate flowdown & traceability to Level 1 reqs at MDR- Detailed walkthrough of MRD Level 2 reqs traceability and assignment at SRR- Initial entry of MRD Level 2 reqs into DOORS database for mgmt and tracking- Define initial SDO Doc Tree, detailing subsystem reqs documentation structure & responsibility

- MRD reviewed and baselined, entered into DOORS for reqs management & tracking; SDO document tree updated with SDO core documents and allocations

Validation & Verification

- Update MRD Level 2 reqs with verification information and use process to check validity of reqs - Preliminary verification information incorporated into MRD; Reqs validation via Peer & PDR reviews, DOORS entry started, verification matrix baselined or in process

Interfaces & ICDs - Baseline and release initial documents and ICDs on SDO Document Tree - MRD, Subsystem Level 3 reqs baselined; ICD’s in process

Mission Environments

- Complete more detailed radiation environment assessment and Observatory ray trace- Update contamination assessment and complete draft Contamination Control Plan- Begin evaluation and tracking of parts and materials for use in identified flight environment- Update flight operational & test environments in Systems Verif & Envi Def document

-Environments identified and documented-SDO Verif and Envi Reqs Doc baselined-Ray trace updated-Contamination assessment completed (Contam PDR)- Parts ID, evaluation, & tracking

Technical Resource Budget Tracking

- Bring resource allocations under CM at beginning of Phase B within appropriate margins- Track and control resource allocations to complete Phase B within PDR margin allocations

-SDO technical resources under CM control-All technical resources within PDR margin allocations

Risk Management - Complete initial FMEA of preliminary design concept and fold results back into design- Update fault tree analysis and reliability block diagrams & use to further optimize design concept- Ongoing identification, classification, & reporting of risk items per Risk Mgmt Plan & Procedures

-Prelim reliability studies completed for each subsystem as part of Subsystem PDR process-Risk Mgmt process ongoing per Risk Mgmt Plan

System Milestone Reviews

- Hold subsystem peer reviews and PDRs to review Level 1 reqs and initial design concepts- Hold PDR for external review team- acts as review milestone for progression Phase C

- Subsystem PDR held- PDR packages available

Configuration Management & Documentation

- Initiate CCB process to address changes to configured documents- Bring Level 1 Reqs, MRD Level 2 Reqs, and Level 3 Subsystem spec under CM

- MRD, Other Level 2 Docs, Level 3 Reqs docs brought under CM

System Engineering Management Plan

- Update SEMP for Phase C Design activity plans to ensure system is “implemented right” - SEMP updated and baselined for entry into Phase C

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Mission Overview Page 27SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO Phase C ActivitiesSystem Design

Phase C

Understanding the Objectives

- Track any changes to Level 1 reqs (changes req NASA HQ approval)

Operations Concept Development

- Complete SDO Mission Phases definitions and SDO Operation Concept Document and bring document under CM

Architecture & Design Development

- Begin ETU design process; use ETU for design validation and for initial interface testing across subsystems for risk reduction

Requirements Identification & Management

- Track changes to Level 2 MRD and Level 3 reqs using DOORS database for reqs mgmt

Validation & Verification - Begin effort to verify all reqs that identify analysis as verification method- Begin formulation, development and planning for Comprehensive Performance Test (CPT), used to validate reqs and system functionality and performance

Interfaces & ICDs - Baseline and release component and lower level ICDs

Mission Environments - Update and maintain environmental assessments and plans- Continue evaluation and tracking of parts and materials for use in identified flight environment- Update flight operational & test environments in Systems Verif & Envi Def document for use in subsystem and Observatory verification program

Technical Resource Budget Tracking

- Track and control resource allocations to complete Phase C within CDR margin allocations

Risk Management - Complete initial FMEA of flight design concept and assess results- Update fault tree analysis and reliability block diagrams & use to evaluate design concept- Ongoing identification, classification, & reporting of risk items per Risk Mgmt Plan & Procedures

System Milestone Reviews - Hold subsystem CDRs to review flight design concepts- Hold CDR for external review team- acts as review milestone for progression Phase D

Configuration Management & Documentation

- Bring flight drawings and ICDs under CM

System Engineering Management Plan

- Update SEMP for Phase D Development activity plans to ensure flight system is properly tested and verified

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Mission Overview Page 28SDO Preliminary Design Review (PDR) – March 9-12, 2004

SDO SRR/SCR• SDO SRR/ SCR held April 8-11 2003

– Objectives• Demonstrate that the system requirements are clearly defined and reflect mission objectives• Demonstrate that the Mission architecture/design/operations concept is acceptable

o i.e. system fulfills mission objectives and can be built within the project constraints

• Demonstrate that a preliminary development flow and preliminary product verification program are defined

• Demonstrate mission requirements, architecture/design, and operations concept is developed and documented at a level sufficient to proceed into preliminary design

• SRR/SCR RFA status:• Received 54 RFAs

Status as of PDR presentation submission deadline• 51 dispositioned by SDO team and submitted for closure review by Code 300 & Independent Review

teamso 34 closed by Code 300 Review Chairo 17 still remain open pending closure review by Code 300 Review Chair

• 3 remain open

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Mission Overview Page 29SDO Preliminary Design Review (PDR) – March 9-12, 2004

Open SDO SCR RFAs• The following SCR RFAs were still open as of the PDR presentation deadline submission

date• Formal responses for each of these RFAs are available as parts of SCR RFA status package

– SCR RFA #19 Document Launch Window Constraints– SCR RFA #43 Evaluate heat rise in MMIC to avoid Tjunc above 125C; consider alternate

design configurations– SCR RFA #53 Examine and define reliability triggers for end of life disposal

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Mission Overview Page 30SDO Preliminary Design Review (PDR) – March 9-12, 2004

Mission Systems Summary– Reviews of system and subsystem requirements, designs, and operations concept are

mutually consistent and contain sufficient detail/ maturity to proceed with detailed design activities

• Requirements clearly allocated and flow-down to the subsystem level shown, as well as traceability to higher-level reqs

• Design concept meets functional and performance requirements based operations concept (both system and subsystem level)

o Architecture trades of various implementation concepts as well as those considered to enhance mission reliability have been completed and documented

• Project and review team review of subsystems requirements, designs, and implementation concepts (Reqs baseline process, Peer reviews, Subsystem PDRs, etc.)

• Project drivers and risks are clearly identified and tracked as part of ongoing SDO process

– Sufficient detail in the preliminary design to support cost and schedule estimates for phases C, D, & E

– Technical resources and budgets have been established, are clearly allocated and within acceptable margins

– Plan for implementation of Phases C, D, E are clearly laid out in the Systems Engineering Management Plan

Ready to proceed into the detailed design phase