Published on

  • Be the first to comment

  • Be the first to like this

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. The Role of Science and Operations in the James Web Space Telescope Mission Development Presenter D.G. Hunter Co-authors H.S. Stockman K.S. Long Track T5 May 20, 2004
  2. 2. JWST Science <ul><li>Detect First Light (After the Big Bang) </li></ul><ul><ul><li>First luminous objects - protogalaxies, supernovae, black holes </li></ul></ul><ul><li>Assembly of Galaxies </li></ul><ul><ul><li>Merging of protogalaxies, effects of black holes, history of star formation </li></ul></ul><ul><li>Birth of Stars and Planetary Systems </li></ul><ul><ul><li>How stars form in dust clouds </li></ul></ul><ul><ul><li>How chemical elements are produced and recirculated </li></ul></ul><ul><li>Planetary Systems and the Origins of Life </li></ul><ul><ul><li>Formation of planets </li></ul></ul><ul><ul><li>Direct observation of other systems </li></ul></ul><ul><ul><li>Outer Solar System </li></ul></ul>
  3. 3. Observatory Design Features Science Instruments Spacecraft Sunshield 25 m 2 Primary Mirror
  4. 4. JWST Will Operate at Sun-Earth L2 <ul><li>L2 allows blocking Sun, Earth & Moon light </li></ul><ul><li>Passive cooling to ~50K </li></ul><ul><li>Stable environment </li></ul><ul><li>Easy communication </li></ul>
  5. 5. Science Instruments Guider MIRI NIRSpec NIRCam
  6. 6. Science Instruments <ul><li>Mid-Infra-Red Instrument (MIRI) </li></ul><ul><ul><li>100x sensitivity over previous systems </li></ul></ul><ul><ul><li>Imaging and spectroscopy capability </li></ul></ul><ul><ul><li>5 to 28 microns </li></ul></ul><ul><ul><li>Cooled to 7K by Cryostat or Cyrocooler </li></ul></ul><ul><ul><li>Combined ESA/NASA contributions </li></ul></ul><ul><li>Fine Guidance Sensor (FGS) </li></ul><ul><ul><li>Ensures guide star availability with >95% probability at any point in the sky </li></ul></ul><ul><ul><li>Includes Tunable filters for Narrowband Imaging </li></ul></ul><ul><ul><li>CSA provided </li></ul></ul><ul><li>Near Infra-Red Camera (NIRCam) </li></ul><ul><ul><li>Detects first light </li></ul></ul><ul><ul><li>0.6 to 5 microns </li></ul></ul><ul><ul><li>4 Imaging modules each with a 2.3’ x 2.3‘ FOV (short 4kx4k, long 2kx2k) </li></ul></ul><ul><ul><li>Coronagraph capability </li></ul></ul><ul><ul><li>FPA’s passively cooled to 30K </li></ul></ul><ul><ul><li>UofAz/LMATC instrument </li></ul></ul><ul><li>Near Infra-Red Spectrometer (NIRSpec) </li></ul><ul><ul><li>Studies galaxy formation, clusters, chemical abundances, star formation, and kinematics </li></ul></ul><ul><ul><li>0.6 to 5 microns </li></ul></ul><ul><ul><li>Simultaneous spectra of >100 objects </li></ul></ul><ul><ul><li>9 square arc minute field of view </li></ul></ul><ul><ul><li>FPA’s passively cooled to 30K </li></ul></ul><ul><ul><li>Resolving powers of ~100 and ~1000. </li></ul></ul><ul><ul><li>ESA provided with NASA Detectors & Microshutter </li></ul></ul>
  7. 7. Operations <ul><li>Five year mission lifetime - propellant tanks sized for 10 years </li></ul><ul><li>Guaranteed Time Observations for Instrument Scientists </li></ul><ul><li>General Observing via a peer reviewed proposal selection process (as for the Hubble Space Telescope) </li></ul><ul><li>Scheduling (long-term and short-term observation plans) </li></ul><ul><li>Event driven execution of uploaded operations plan </li></ul><ul><li>On-board procedures, high level commands </li></ul><ul><li>Data download and archive </li></ul><ul><li>On-the-Fly data calibration </li></ul>
  8. 8. Mission Schedule
  9. 9. Mission Participants <ul><ul><li>NASA </li></ul></ul><ul><ul><li>ESA </li></ul></ul><ul><ul><li>CSA </li></ul></ul><ul><ul><li>Project lead at Goddard Space Flight Center (GSFC) </li></ul></ul><ul><ul><li>Observatory Contractor: Northrop Grumman Space Technology (NGST) </li></ul></ul><ul><ul><li>Science and Operations Center at the Space Telescope Science Institute (STScI) </li></ul></ul>
  10. 10. The STScI Hubble Heritage <ul><li>Successful preparation and checkout of 10 instruments (+2 in SM4). </li></ul><ul><li>Proven and evolving software systems for all aspects of science operations: </li></ul><ul><ul><li>Proposal management </li></ul></ul><ul><ul><li>Guide star selection (GSC II) </li></ul></ul><ul><ul><li>Science planning (APT) </li></ul></ul><ul><ul><li>Scheduling (Spike) </li></ul></ul><ul><ul><li>Hubble archive </li></ul></ul><ul><ul><li>“ On-the-fly” calibration management (OPUS) </li></ul></ul><ul><ul><li>Grants management (GMS) </li></ul></ul><ul><li>Outstanding record of public and astronomical outreach </li></ul>
  11. 11. STScI Role in JWST <ul><li>Manage the science program from observing program solicitation and selection to grants management and science outreach support. </li></ul><ul><li>Operate JWST - beginning in commissioning </li></ul><ul><li>Develop the science and operations ground systems </li></ul><ul><li>Perform ground segment verification </li></ul><ul><li>Perform end to end testing </li></ul><ul><li>Scientific and Public outreach </li></ul><ul><li>Support the Project and JWST teams during the development phase: </li></ul><ul><ul><li>Mission architecture & system engineering </li></ul></ul><ul><ul><li>ISIM & Scientific instruments & ISIM flight software </li></ul></ul><ul><ul><li>Optics and wavefront sensing and control </li></ul></ul><ul><ul><li>Science and operations input to many working groups </li></ul></ul>
  12. 12. The JWST Ground System
  13. 13. JWST Ground Processes Proposal Preparation Proposal Selection Science Planning Operations Scheduling Flight Operations Data Management Data Archive Ground Sys Engineering/ Maintenance Flight System Eng Testbeds & Simulators Flight Dynamics Wavefront Control Instrument Calibration Command Management Flight SW Maintenance Astronomers <ul><li>Uplink </li></ul><ul><li>- Observation Plan </li></ul><ul><li>- Ephemeris </li></ul><ul><li>- Commands </li></ul><ul><li>Flight S/W </li></ul><ul><li>Ranging </li></ul>JPL Deep Space Network JWST Ground Processes and Key Relationships <ul><li>Downlink </li></ul><ul><li>- Event Logs </li></ul><ul><li>R/T Eng Telemetry </li></ul><ul><li>Recorded Telemetry </li></ul><ul><li>Ranging </li></ul><ul><li>Flight S/W </li></ul>JWST - On-Line Documentation - Electronic Forms - Proposal Tools - TAC review - Electronic Forms - Long-term plan - Weekly schedule - WFE Sensing - WFE Control - Station Keeping - Weekly Schedule - Contact Schedule - Eng Activities - Command Loads - R/T Operations - Uplinks - State evaluation - Data capture - Eng Trend - L0 Processing - Sci Data QA - SI Calibration - Short Term Storage - Long-Term Storage (Sci & Eng) - Browsing - Retrieval - SI Calibration - Distribution - WFE Determination - Mirror Actuator Commands - FSW Upgrades - Patches - Tables - SI Procedures - Anomaly Analysis - GSW Requirements - Data Base Management - Vendor OS & Tools - Ground HW / SW Maintenance / Upgrades - H/W Testbeds - SW Simulators - System I&T - SSM/OTA/ISIM Test Environment - Orbit Determination - Station Keeping - Ephemeris - Momentum Monitoring - Anomaly Analysis - Eng Trend Analysis - Degradation Prediction - FSW Requirements - Algorithms - Reference Data - Performance Reports - Proposals - Science Data - Visit Scripts
  14. 14. The Planning System Interface <ul><li>Exposure Time calculators </li></ul><ul><li>Optimum background/roll range </li></ul><ul><li>Orientation planning with Guide Star Catalog II </li></ul><ul><ul><li>Target coordinates in JWST frame </li></ul></ul><ul><ul><li>NIRSpec target selection tool </li></ul></ul><ul><ul><li>Allowable & Optimum roll angles </li></ul></ul><ul><ul><li>Dither pattern selection and optimization </li></ul></ul><ul><ul><li>Predicted glare from bright objects </li></ul></ul><ul><ul><li>Acquisition/offset target selection </li></ul></ul><ul><li>Calibration & engineering operations will also be planned using this planning tool. </li></ul>Hubble Planning Tool Advanced Camera for Surveys
  15. 15. Participation in Development <ul><li>Inform the Observatory development process of the science and operations drivers for, and consequences of each design decision. </li></ul><ul><li>Ultimate objectives: </li></ul><ul><ul><li>achieving a high scientific return, </li></ul></ul><ul><ul><li>reduced lifecycle cost, </li></ul></ul><ul><ul><li>efficient operations and design. </li></ul></ul>
  16. 16. Influencing Development - 1 <ul><li>Develop and maintain the Mission Operations Concept </li></ul><ul><li>Systems Engineering </li></ul><ul><ul><li>Participate in requirements development. </li></ul></ul><ul><ul><li>Evaluate the operations consequences for system level trades. </li></ul></ul><ul><li>Science Instrument Teams </li></ul><ul><ul><li>Develop operation concepts with common approaches </li></ul></ul><ul><ul><li>Develop the calibration plans </li></ul></ul><ul><ul><li>Gain knowledge of the instruments’ design & behavior </li></ul></ul><ul><ul><li>Develop the tools and resources the astronomy community will need for high yield science. </li></ul></ul><ul><li>Flight software </li></ul><ul><ul><li>Ensure commonality of commanding approaches, syntax and terminology </li></ul></ul><ul><ul><li>Develop on-board procedures. </li></ul></ul>
  17. 17. Influencing Development - 2 <ul><li>Integration and Test </li></ul><ul><ul><li>Develop and manage the Project Reference Database </li></ul></ul><ul><ul><li>Provide test conductors who will migrate to the operations team </li></ul></ul><ul><ul><li>Develop operations procedures - test against simulators and with the ground system in the loop with the flight systems. </li></ul></ul><ul><li>Commissioning </li></ul><ul><ul><li>Develop plans and procedures, working with the flight systems developers </li></ul></ul><ul><ul><li>Operate observatory. </li></ul></ul>
  18. 18. Value Added - Mission Simulator <ul><li>JWST Mission Simulator - simulates execution of science observations </li></ul><ul><ul><li>Informed the transformation of the science objectives into the observatory requirements. </li></ul></ul><ul><ul><li> </li></ul></ul><ul><ul><li>Important science influence on requirements </li></ul></ul><ul><ul><ul><li>Field of Regard </li></ul></ul></ul><ul><ul><ul><li>Continuous viewing zone </li></ul></ul></ul><ul><ul><ul><li>Continuous exposure at same orientation… </li></ul></ul></ul>Anti-Sun LOS Allowable Observatory Field-of- Regard SUN Exclusion < 27° from Anti-Sun Exclusion Zone < 85 ° from Sun Observatory Field-of-Regard (FOR)
  19. 19. Value Added - Fine Guidance Sensor Architecture <ul><li>Separation of Fine Guidance Sensor from Near-Infrared Camera. </li></ul><ul><ul><li>Reduced operational complexity </li></ul></ul><ul><ul><li>Improved architecture for science </li></ul></ul><ul><ul><li>Improved management structure. </li></ul></ul>
  20. 20. Value Added - Day in the Life Simulations <ul><li>Developed prototype of flight software for event-driven operations including: </li></ul><ul><ul><li>Executive and processing functions </li></ul></ul><ul><ul><li>On-board procedure scripts </li></ul></ul><ul><ul><li>Commands and telemetry for science instruments and spacecraft </li></ul></ul><ul><li>Executed on top of Command and Data Handling System flight code running on a flight representative single board computer. </li></ul><ul><li>Loaded and ran six days of observation plans for three science instruments. </li></ul><ul><li>Produced detailed event logs plus memory and CPU statistics. </li></ul><ul><li>The exercise: </li></ul><ul><ul><li>developed detailed requirements, </li></ul></ul><ul><ul><li>confirmed the event driven design with flight like operations, </li></ul></ul><ul><ul><li>produced flight like prototypes for the flight software. </li></ul></ul><ul><li>Now preparing to implement more complex scenarios. </li></ul>
  21. 21. System Trades - Momentum Management <ul><ul><li>The JWST attitude required for each science observation results in solar torque being generated by the sunshield. </li></ul></ul><ul><ul><li>Unloading momentum disturbs the orbit. </li></ul></ul><ul><ul><li>Propellant consumption affects the mission lifetime. </li></ul></ul><ul><ul><li>Constraining the scheduling of observations to manage momentum accumulation adds significant complexity and may compromise science. </li></ul></ul>
  22. 22. Ongoing Challenges <ul><li>Aspects of operations are highly sensitive to the flight segment design, such as: </li></ul><ul><ul><li>Momentum management - smaller sunshield is better </li></ul></ul><ul><ul><li>Stray light avoidance - larger sunshield is better </li></ul></ul><ul><ul><li>Both affect scheduling of science observations. </li></ul></ul><ul><ul><li>Importance of operations involvement in design trades </li></ul></ul><ul><li>Funding profile - Pressures on Phase A/B funding </li></ul><ul><ul><li>Lowest lifecycle cost often requires higher initial outlay but few missions have sufficient early funding. </li></ul></ul><ul><ul><li>Prioritization of effort in high impact areas. </li></ul></ul><ul><li>Not everyone has learned the same lessons </li></ul><ul><ul><li>Different missions follow different paradigms </li></ul></ul><ul><ul><li>Demonstrate merits of approach by example. </li></ul></ul>