the ramaty high energy solar spectroscopic imager − receiving review − may 6, 2002 rhessi...

The Ramaty High Energy Solar Spectroscopic Imager − Receiving Review − May 6, 2002

Agenda

09:00 PDT Mission Overview R. Lin

- Mission Goals - Science Team - Instrument Overview - First Science Results

09:10 Mission Status M. Bester

- Mission Requirements - Spacecraft Systems - Ground Systems Design - IT Security - Mission Status - Phase E Organization - Sustained Engineering & Maintenance - Problems & Resolutions

RHESSI RECEIVING REVIEW


Agenda (continued)

09:30 Mission Operations Status M. Lewis

- Launch & Early Orbit Checkout - Normal Operations - Contingency Operations - Mission Planning - Scheduling of Pass Supports - Spacecraft Commanding - Real-time Health & Safety Monitoring - Trend Analysis - Anomaly Reporting - Spacecraft Simulator - Configuration Control - Flight Operations Team - FOT Responsibilities



Agenda (continued)

09:50 Instrument Status Spectrometer D. Smith Imager G. Hurford

10:10 Science Operations T. Quinn - Level Zero Processing - Data Archiving

Science Data Analysis G. Hurford

J. McTiernan 10:25 Future Plans, Misc. Issues R. Lin et al.



RHESSI Receiving Review

Mission OverviewDr. Robert P. Lin

Principal InvestigatorUniversity of California at Berkeley

Imager – side viewImager – Side View

Mechanical Cryocooler



Mission StatusDr. Manfred BesterProject Manager

University of California at Berkeley


Mission Requirements

Mission Element Requirement

Launch Vehicle Adequate capability to achieve mission orbit

Orbit 600 x 600 km at 38 degMinimize radiation damage, maximize life time and ground station coverage

Launch Date Mid 2000 to end of 2001, near solar maximum

Mission Life Time 2 years nominal, 3 years desired to capture sufficient solar events to perform analysis

Data Volume 16 Gbits storage, 8 Gbits/day downlink

Ground Station Meet telemetry and command requirements, simplify operations and reduce costs

Attitude Sun pointed to 0.2 deg such that entire solar disk is within instrument FOV

Spin Rate 12-20 RPM, required by imaging sample rate


Spacecraft Systems

Spacecraft Bus (Spectrum Astro) Spin Stabilized Sun Pointed Platform ACS Comprises Coarse and Fine Sun Sensors,

Magnetometer and 3 Torquer Rods 4 Solar Panels, 11 NiH2 15 A-hr CPVs S-Band Transceiver, 4 Antennas

Instruments Imager Including SAS, RAS, ADP (PSI) Spectrometer, IDPU, PMT-RAS, PD (UCB)


Ground Systems Design


U.C. Berkeley Mission Operations Center

BGS Antenna, Equipment Racks and FOT Workstations at the UCB Mission Operations Center


IT Network Security

Revised IT Network Security Plan Submitted to GSFC Covers Joint RHESSI and FAST Operations

Enhanced Security Features in MOC Include: Cardkey Entry System Access to MOC Controlled by U.C. Police Department Alarm System Tied into U.C.P.D. Access Restricted to Personnel Essential for Flight and

Ground Station Operations Video Surveillance Systems


Launch and Ascent to Orbit

Drop Time: 05-Feb-2002 20:58:10.665 UTC


Mission Orbit

Target Orbit: 600.00 x 600.00 km at 38.00 deg

Orbit at Payload Separation: 600.24 x 586.85 km at 38.02 deg

Orbit at L+90:603.51 x 578.13 km at 38.03 deg


Ground Station Coverage


Mission Status

Launch & Orbit Insertion Including Sun Pointing Nominal First Acquisition at Berkeley Successful Spacecraft Bus Nominal (Power, ACS, C&DH, Flight

Software, Thermal, Telecomm) Instrument Turn On Nominal Cryocooler Now Running at 52 W First Flare Observed at L+7 Days Spacecraft Fully Autonomous at ~ L+50 Days


Science and Engineering Data Recovery

Ground Station BGS WLP WHM AGOPasses to Date 526 302 100 43

Total Access Time Until L+90: > 8,400 min

Mission Data Recovery: > 98%

Mission Requirement: 8.0 Gbits/day

Mission Achievement at L+90: 1.5 Tbits (16.7 Gbits/day)


Phase E Organization


Sustained Engineering & Maintenance

Organization Responsibilities in Phase A-D Support in Phase E

U.C. Berkeley Project ManagementSpectrometer & Instrument Data Processor Spacecraft Integration and TestBerkeley Ground Station, MOC/SOC DevelopmentMission Operations, Flight Dynamics & Data Analysis

Sustained Engineering Support(UCB Engineering Team)GDS, MOC & SOC Systems(UCB Operations Team)EMP Systems (R. d’Angelo)

NASA / GSFC Grid Mounts, Grid CharacterizationCryogenics Design, Flight Cryocooler, Instrument BlanketsI&T Hardware and Software Support (ITOS, Imaging)Data Analysis Software, Data Analysis and Archiving

Data Analysis(B. Dennis)ITOS Software(G. Greer)

Paul Scherrer Institute Imaging Telescope, Solar Aspect and Roll Angle SystemsAspect Data Processor

SAS, RAS & ADP Support(M. Fivian)

Spectrum Astro Spacecraft BusI&T and L&EO Support to UCB

S/C Bus, Hot Bench & Flight Software (R. Wanner)

SpaceWorks Spacecraft Support N/A

NASA / KSC Launch Vehicle Contract N/A

Orbital Sciences Corporation Launch Vehicle N/A


Problems & Resolutions

Anomaly Detection Operations Personnel on Console Paging of Operators via SERS

Anomaly Resolution Assessment by FOT, Mission Operations Manager, Mission

Operations Scientist Quick Interaction with Subsystems Engineers, Instrument

Scientists and PI Anomaly Resolution According to Contingency Plan


Budget & Physical Constraints

RHESSI Team Awaits Approval of Phase E Budget Updated IT Network Security Plan Has Been Submitted

External Supports PSLA for NASA GN Support at Wallops Ground Station MOU for Pass Supports at Weilheim Ground Station

Expected Mission Life Time At Least 3 Years Cryocooler Performance Much Better Than Anticipated Detectors Are Twice as Sensitive as Anticipated Time at Which Minimum Science Will Be Reached Depends on Solar

Activity



Mission OperationsMark Lewis

Mission Operations ManagerUniversity of California at Berkeley


Launch and Early Orbit Checkout

RHESSI Launched on February 5, 2002 at 20:58 UTC Launch resulted in nominal orbit insertion

~600 km circular orbit, 38 degree inclination L&EO Operations conducted with Spectrum Astro support First RHESSI contact on orbit came at 22:40 UTC

BGS locked onto telemetry without difficulty Spacecraft was healthy, power positive, with arrays deployed Spacecraft pointing was within 10 degrees of the sun All temperatures were nominal Commanding attempts were successful


Launch and Early Orbit Checkout

Major Milestones Accomplished During First Week Set spacecraft clock Loaded Automatic Time Sequence (ATS) command load Tested all downlink rates (125k, 1M and 4M) Powered on the IDPU Turned on the cryocooler; ramped power to 76W; then down to 40W Turned on Particle Detector Powered SSR; Partitioned SSR; Began recording data Turned on Imager; Collected high rate imager data Powered Germanium Detectors; ramped to full power Spun spacecraft to 14 RPM and balanced


Launch and Early Orbit

Additional Milestones Since Launch RHESSI captured its first flare on February 12, 2002 Spun up to 15 RPM and balanced Tuned Particle Detector SAA detection algorithm Exercised attenuators; initiated autonomous shutter control Tuned thresholds for all 9 GEDs RHESSI captures first X-class flare on April 21, 2002 FOT recovered from CPU reset in just 2 orbits (~3 hours)

RHESSI never stopped taking data


Normal Operations

Highly Autonomous Operations Planned for RHESSI 6 BGS passes per day are currently staffed

3-5 Wallops per day are not staffed Weilheim passes requested during times of high solar activity

Only post-pass data available BGS passes will eventually be unstaffed

All passes will be monitored by VMOCC/SERS Violations of limits or configmon rules result in paging FOT

ATS loads currently cover 48 hour period FOT analyze spacecraft trend plots Ops Manager present during any unusual commanding


Mission Planning

Scheduling of Pass Supports SatTrack produces view periods and link margins

BGS passes scheduled directly from SatTrack products Desired Wallops passes sent to Wallops for scheduling Weilheim passes requested on a best effort basis Schedule from Wallops and Weilheim merged with BGS passes

SSR Memory Management High magnetic latitude decimation during orbital night

Particle storms can fill SSR at 1% per minute Decimation times manually inserted into loads Next version of SatTrack will include high magnetic latitude zones


Configuration Control

All RHESSI GSE is Under Configuration Control Changes to GSE hardware/software require CCB approval Changes to Ops Workspace tested on the open network Software configurations controlled using SCCS

If a problem arises, configuration can easily be rolled back

Configuration Control Board The CCB includes Mission Ops Manager, Mission Ops

Scientist, Science Ops Manager, Network Administrator and the Mission Director (at GSFC)


Spacecraft Simulator

The RHESSI Spacecraft Simulator, aka The Hotbench Located at SSL Assembled by Spectrum Astro

Includes CPU, IDPU, SSR and simulation of some hardware ITOS used to for command and control, through dedicated PTP

Allows for loading and testing of Flight Software (IDPU also) Includes AC1000 to simulate ACS sensor inputs and orbit

Limited hardware modeling (ie no temp sensors, etc) Any change to Flight software is first tested on Hotbench

Currently being used to test off-pointing patch Used to test new RTSs

Hotbench is used for training exercises


Flight Operations Team

FOT Staffing and Experience Mission Operations Manager

Mark Lewis – EUVE, FAST, RHESSI (10 years) Spacecraft Controller/Programmer

Joseph Rauch-Leiba – FAST, RHESSI (5 years) 2 Spacecraft Controllers/Mission Planners

Jeremy Thorsness – EUVE, RHESSI (5 years) Pam Lehr – FAST, RHESSI (3 years) Pam is leaving in August; will not be replaced

1 Backup Spacecraft Controller (FAST Controller) Marty Eckert – EUVE, FAST, RHESSI (10 years)



FOT Responsibilities Health and safety of the spacecraft is prime responsibility

Currently, all 6 BGS passes per day are staffed by at least one spacecraft controller

Wallops and Weilheim passes are taken as unstaffed autonomous BGS passes will be unstaffed once limits are tuned better and

spacecraft behavior is well understood VMOCC/SERS is used to autonomously monitor health and status

VMOCC/SERS monitors vc0 and vc1 from all contacts If an anomaly is detected, a page and email is sent out to FOT Paging is persistent and will continue until problem file is handled



FOT Responsibilities – cont. Produce Automatic Time Sequence (ATS) loads

Merge SatTrack products and contact schedules in CMS Produce ATS load; manually edit load as necessary Check load twice (different people)

Load ATS to spacecraft every other day Dump vc1 data during BGS contacts Adjust attenuator states as necessary Produce and monitor spacecraft trend data


Trend Analysis

Daily Trend Plots Plots of important systems are plotted daily using IDL Plots are available on the web

http://sprg/~hessiops/state-of-health/welcome.html

Long-Term Trend Plots Currently produced manually by FOT Produced for investigations, or as requested by team Automated solution is in development

Plots will be put on web once automated

http://sprg/~hessiops/state-of-health/welcome.html


Contingency Operations

Anomalies May be Detected in Real-time or by VMOCC/SERS Spacecraft Controller on-shift/on-call evaluates severity of anomaly

Two-way alpha-numeric pager provides information on rules violated Controller can access problem report remotely Controller can view most relevant spacecraft data from last BGS pass

http://hessi.ssl.berkeley.edu/ground_systems/hessi_spacecraft_status.html

Controller Notifies Ops Manager Instrument specialists or spacecraft engineers called in as necessary Mission Director notified in a timely manner

http://hessi.ssl.berkeley.edu/ground_systems/hessi_spacecraft_status.html


Contingency Operations

Anomaly Resolution Spacecraft Controllers are trained and authorized to respond

immediately to anomalies when necessary With short passes, controllers must be ready to safe the spacecraft

quickly, before seeking outside authorization Anytime the spacecraft is not in immediate danger, Ops Manager will be

contacted before proceeding Ops Manager should be present during anomaly recovery

New contingency procedures developed and implemented with system experts, on as needed basis Lessons learned used to update existing contingency procedures

Anomalies and resolution reported in updates to RHESSI team and in weekly report to Mission Director


Operations Summary

L&EO Went Smoothly RHESSI is performing great Many activities were finished ahead of schedule Instruments were on and taking data after one week Spacecraft was fully checked out after six weeks

Moving Towards One Shift Operation Most routine functions have already been automated Autonomous monitoring elements are in place

Fine tuning of rule base nearly complete



Instrument Status - SpectrometerDr. David Smith

Spectrometer ScientistUniversity of California at Berkeley



Instrument Status - ImagerDr. Gordon Hurford

Imager ScientistUniversity of California at Berkeley


IMAGING SYSTEM CHARACTERISTICS / STATUS

Imaging principles

Uses a set of 9 rotating modulation collimators.

Each grid pair rapidly time-modulates the incident x-ray flux..

Data system records arrival time and energy of each detected photon.

Analysis software uses list of detected photons to reconstruct image of the source.

Requires good aspect solution and knowledge of grid parameters.

Imaging characteristics

Well-suited to relatively simple source geometries. (‘TRACE-like’ images are not expected.)

Inherently accurate absolute source locations (~1 arcsec)

Technique is inherently ‘robust’. (Depends on knowledge rather than control of instrument parameters.)

Imaging system and software are performing well.

System is yielding science-quality images with photometry that supports imaging spectroscopy.


RHESSI IMAGING – SOLAR ASPECT SYSTEM (SAS)

Successfully providing pitch and yaw aspect for image reconstruction.

Internal consistency checks agree to better than the 0.4 arcsec rms requirement.

Good prospects for stand-alone limb science (e.g. helioseismology).

Post-sunrise spacecraft dynamics briefly move Sun outside SAS ‘6-limb’ field of view, resulting in reduction in aspect accuracy for 1 or 2 minutes after ‘sunrise’.

Analysis software upgrade will compensate for this.

Gradual loss of sensitivity (8.3% per month) x200 sensitivity margin Exponential model lifetime greater than 5 years


RHESSI IMAGING – ROLL ASPECT SYSTEM (RAS)

Side-looking CCD-based star scanner to provide roll aspect data

Fully operational, but interaction of earth albedo and current anti-blooming provision results in orbit-dependent mid-day data gap of 0 to 10 minutes.

Revised parameterization should improve this.

Because of manpower limitations, current workaround uses PMTRAS for roll aspect.


RHESSI IMAGING - ROLL ASPECT FROM PMTRAS

Side-looking PMT-based star scanner provides roll aspect.

Added as a backup because of subsequently-resolved RAS scheduling concerns during phase C/D.

Currently providing roll aspect which meets 1-arcminute rms requirement

PMTRAS analysis software is not yet fully transparent to user.

Sometimes requires manual override of star identification.


IMAGING SYSTEM ISSUES

Detector 2 threshold ~10 percent loss of overall effective area below 20 keV Introduces uncertainty in source sizes measurements in range 2.5 to 3.5 arcsec

below 20 keV. Future exploitation of harmonics may compensate for this Some reduction in dynamic range of high resolution images

Data gaps Software compensation to minimize impact on imaging is in place. ~10 percent loss of sensitivity in typical applications

Roll aspect solution not yet fully automated Manual workaround is in place. Algorithm improvements are in progress.

Grid phase calibrations not yet complete. Preliminary phase calibrations in place for grids 3 through 9. (6.8 arcsec resolution) Phase calibration for grids 1 and 2 are in progress. (2.3 arcsec

resolution)


IMAGER SELF-CALIBRATION

Achievement of high dynamic range images depends on good knowledge of grid transmission and modulation efficiency.

Pre-launch calibrations of grids were self-consistent to 2% level.

Inherent redundancy enables the transmission and modulation parameters to be refined using post launch data.

Improved parameters and algorithms can be applied retroactively to complete RHESSI database.



Science OperationsTim Quinn

Science Operations ManagerUniversity of California at Berkeley


Science Operations

Level Zero Processing HESSI Science Operations are fully autonomous Ground Station contact files (VC0-VC3) are transferred to

SUN Enterprise Server post pass UNIX shell scripts call IDL routines which perform level

zero processingConvert contact files (VC1-VC3) to FITS filesProduce QUICKLOOK data and append to FITS files

Count Rates, Packet Rates, and Flare ListUpdate HESSI databaseProduce count rate plots accessible from

rhessidatacenter.ssl.berkeley.edu


Science Operations

Data ArchivingAll Level Zero Products are archived on RAID

systemRaw data files (VC1-VC3) are also archived on

RAID system as well as CD-R



Science Data AnalysisDr. Gordon Hurford

Imager Scientistand

Dr. Jim McTiernanSOC Scientist

University of California at Berkeley


RHESSI DATA ANALYSIS PRINCIPLES

PI team and community have equal access to the data and analysis tools.

Significant effort to make user-friendly interface.

Provision for convenient comparison with other ground and space-based data sets.

Science-driven tradeoffs, which most missions make before the fact. Time resolution Energy range and resolution Spatial resolution Image field of view

Key RHESSI strategy is to defer these tradeoffs to data analysis phase. RHESSI data contains time- and energy-tagged photons Tradeoffs can be made in response to nature of the flare and scientific objectives.


RHESSI DATA PRODUCTS

Basic data product classes (User-selected time, energy and spatial parameters) Light curves Images Integrated energy spectra

Advanced data product classes Feature-based spectra Feature-based light curves

Quick look products are appended to Level-0 database. light curves with 4s time resolution, 8 energy bands representative flare images (limited quality) representative integrated spectra flare lists observing parameters, etc

Most science analyses start from level-0 data.


RHESSI DATA ANALYSIS STATUS

Documented and functional analysis software is on-line and distributed via GSFC Solar Software. Upgrades and improvements continue to be made.

Level-0 database Created at SSL with no routine operator intervention. Opened for general use on March 20. Local access at SSL Mirrored for community access at GSFC and ETH (Zurich) Populated with less than 1 day latency Most quick look products are available. Some reprocessing (~30%) has been necessary. Flare locations and quick-look images to be added when aspect issues resolved.


RHESSI DATA ANALYSIS STATUS

HESSI Experimental Data Center is on-line. Access to Level-0 database Web-based access to analysis tools http://HEDC.ethz.ch/

Documentation and details at

RHESSI SOFTWARE AND DATA ANALYSIS CENTERhttp://hesperia.gsfc.nasa.gov/rhessidatacenter/



Education & Public OutreachDr. Nahide Craig

EPO ScientistUniversity of California at Berkeley


RHESSI EPO at Berkeley

Accomplishments RHESSI Lithograph RHESSI LAUNCH Day

Chabot Science Center SSL - TV Media Coverage Science@NASA on HESSI

NASA Connect “Having a Solar Blast” Video Released to 120,000

Educators RHESSI EPO as a

Model for LWS EPO

Phase E Plans NOBCChE Invited Teacher

Professional Workshop-March 2002 NSTA Conference April 2002

2000 HESSI Lithos Distributed CAL Day OPEN HOUSE April 2002

Lecture & Guided Tour of MOC RHESSI Booth at Campus Lecture at Physics Dept

Dissemination of Materials Summer Teacher Workshops Best of Eclipse Video

Partnerships with SEC Forum and Science Museums & Live Web broadcast from location

the ramaty high energy solar spectroscopic imager − receiving review − may 6, 2002 rhessi...

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