CELT Steering Committee Report

1. CELT Steering Committee Report Jerry Nelson 12 September 2000

2. Membership of Committee and working groups • Steering Committee • Bolte, Mike UCSC • Chanan, Gary UCI • Dekany, Richard JPL • Ellis, Richard Caltech • Ghez, Andrea UCLA • Ian Mclean UCLA • Miller, Joe UCSC co-chair • Nelson,Jerry UCSC • Sargent, Wal Caltech • Steidel, Chuck Caltech co-chair • Tytler, Dave UCSC

3. Membership of Committee and working groups • Telescope Working Group (Responsible for CELT design study, optical design, optical fabrication, telescope structure, active control system of primary) • Antonsson, Erik Caltech • Chanan, Gary UCI • Mast, Terry UCSC • Matthews, Keith Caltech • Nelson, Jerry UCSC chair • Woody, Dave Caltech • Adaptive Optics Working Group(Responsible for the requirements for AO, the design, and the development) • Chanan, Gary UCI • Dekany, Richard JPL chair • Nelson, Jerry UCSC • Quirrenbach, Andreas UCSD

4. Membership of Committee and working groups • Enclosure and Building Working Group(Responsible for the enclosure and support facilities) • Nelson,Jerry UCSC • Tytler, David UCSD chair • Scientific Instruments working Group(Responsible for generating potential scientific instruments and their implied requirements on the telescope system) • Ellis, Richard Caltech • Graham, James UCB • Guhathakurta, Raja UCSC • Kulkarni,Shri Caltech • Larkin, James UCLA • Mclean, Ian UCLA chair • Taylor, Keith Caltech • Vogt, Steve UCSC

5. Membership of Committee and working groups • Science Working Group(Responsible for generating scientific justification) • Bolte, Mike UCSC • Brown, Mike Caltech • Cohen, Judy Caltech • Ellis, Richard Caltech • Ghez, Andrea UCLA co-chair • Jura, Mike UCLA • Steidel, Chuck Caltech co-chair • Site Working Group (Responsible for evaluating potential sites for CELT) • Djorgovski, George Caltech • Miller, Joe UCSC vice chair • Nelson, Jerry UCSC • Quirrenbach, Andreas UCSD • Sargent, Wal Caltech chair

6. CELT Websitehttp://www.ucolick.org/~celt/ • California Extremely Large Telescope • What's New Reports and Notes Internal Documents • Current Schedule Working Groups • Past Events Member Institutions

7. List of CELT Reports • 1. Giant Optical Devices. Jerry Nelson and Terry Mast, Proceedings of the Backaskog Workshop of Extremely Large Telescopes, Anderson, T. ed, pp1-11, June 1999 • 2. CELT Project Plan, (February, 2000) • 3. Design Concepts for the California Extremely Large Telescope (CELT), J. E. Nelson, Proceedings of the SPIE, 4004, 2000. • 4. Systematic Wavefront Control for the California Extremely Large Telescope, R. G. Dekaney and J. E. Nelson, Proceedings of the SPIE, 4003, 2000. • 5. Primary Mirror Segment Fabrication for CELT, Terry S. Mast, Jerry E. Nelson, and Gary Sommargren, Proceedings of the SPIE, 4003, 2000. • 6. Segmented Mirror Control System Hardware for CELT, Terry S. Mast and Jerry E. Nelson, Proceedings of the SPIE, 4003, 2000. • 7. Design Issues for the Active Control System of the California Extremely Large Telescope (CELT), .G. A. Chanan, and E. Sirko, Proceedings of the SPIE, 4004, 2000. • 8. Phasing the Primary Mirror Segments of the Keck Telescopes: A Comparison of Different Techniques Design Issues for the Active Control System of the California Extremely Large Telescope (CELT), Chanan, G. A., Troy, M. and Ohara, C., 2000 • 9. CELT Conceptual Design Plan, Nelson, Mast, Chanan, Dekany (July 2000) • 10. CELT Error Budgets, Terrry Mast and Jerry Nelson (2000) [ in progress ]

8. Overall Plan and Schedule • Three Phases • Conceptual Design • Preliminary Design • Detailed Design • Schedule • Conceptual Design 12 months, starts 1 September 2000 • Preliminary Design 18 months • Detailed Design 18 months • Likely Budget • Conceptual Design $750 K • Preliminary Design $3.0 M • Detailed Design $10 M

9. Conceptual Design Plan • Objectives • Generate a Conceptual Design for a 30-meter diameter telescope. • Develop a set of compelling scientific research areas • Develop conceptual scientific instruments • Develop Observatory requirements • Identify and resolve key technology and cost risk areas • Produce a cost estimate with the likely range of costs • Produce a schedule for the observatory design and construction • Determine the high-priority design and technology development tasks for all activities leading up to and including the Critical Design Review. • Generate a work plan and budget for the Preliminary Design phase • Budget • $750 K • In kind contributions from Caltech, UC, LLNL

10. High Risk areas • High Risk Areas to be addressed in the Conceptual Design phase • Primary Mirror design, fabrication, support, and control • Wind effects on the telescope structure and optics • Adaptive Optics feasibility • Scientific Instrumentation feasibility

11. Reviews and Deliverables • Reviews • Internal Status Reviews by Steering Committee: Quarterly • Working group meetings as needed • CELT Workshop for internal CELT participants • Conceptual Design Review (CoDR) • Deliverables • Report and Technical Notes Series describing the results of this phase • The “Green Book” ; A full summary of the CELT project; the basis for a Conceptual Design Review • CELT Website containing all Reports and Project Information

12. List of Tasks -overview • There are many activities that will be important to complete to make CELT a success. • We have selected for the Conceptual Design Phase funding those tasks that: • 1) are critical to reducing the CELT cost or technical risk • 2) will have within one year significant impact on the telescope design • 3) are not being funded elsewhere

13. Framework for Tasks • Item Task • Observatory requirements 1 • Telescope Design • Error budgets 2 • External design driver:wind 3 • Optical design 4 • Primary mirror 5-17 • Auxiliary optics 18,19 • Telescope structure 20,21 • Adaptive Optics • Modes of operation 22 • Error budgets 23 • Alternative design concepts 24

14. Framework for Tasks (cont) • Item Task • Conceptual Design Review 25 • Preliminary Design plan 26 • CELT working groups 27 • Conceptual Design phase management 28 • CELT website management 29 • Contingency management 30

15. Telescope Geometry • Effort to date is interesting but very incomplete • Contributions from • Dekany • Medwadowski • Meinel • Mast • Nelson • Woody • Two basic upper structures • Quadrupod • Square tube

16. Progress on Telescope Layout

17. Progress on Telescope Layout

18. Progress on Telescope Layout

19. Progress on Telescope Layout

20. Progress on Telescope Layout

21. Progress on Telescope Layout

22. Progress on Telescope Layout

23. Progress on Telescope Layout

24. Progress on Telescope Layout

25. Progress on Telescope Layout

26. Progress on Telescope Layout

27. Requirements (draft) • Elevation range 25°- 89° • Wave length range 0.3µm-30µm • Geometric image quality 0.25 arc seconds (80%) • Wave front error < 100 nm rms(with AO) • Emissivity <0.1 (without cold stops) • Field of view 20 arc minutes • Motion range anywhere in < 5 minutes • Instrument space 12x24m, x2 Nasmyth pl.

28. Nasmyth Platforms, with articulated tertiary • Right Nasmyth, typical instrument axes Blocked by primary

29. Near Term Activities (Sept) • Requirements document • Error budgets • Geometric image blur • Wave front error • Emissivity • Image motion • Wind issues • List questions and discuss with McCallen, White • Stressing fixture • Write requirements • Design stressing fixture

30. Near Term Activities (Sept) • Segment passive support • Write requirements, contract goals • Meet with Gunnels, Hale • Segment displacement sensors • Write requirements, contract goals • Meet with Alan Schier • Segment displacement actuators • Write requirements, contract goals • Meet with Alan Schier • Telescope structure • Write requirements, contract goals • Meet with Medwadowski, Meinel

31. Near Term Activities (Sept) • Strawman design of bearings, drives, encoders • Write requirements, contract goals • Meet with Stan Hermann of VERTEX/RSI • Management • Establish funding, contracts • set up meeting/telecon schedule of design team

32. Tasks for working groups-1 • Steering committee • Requirements review • Quarterly conceptual design review (set dates) • Site • Collect appropriate site data (wind, temp, seeing, etc) • Write report for CoDR on potential sites • Science • Write a quantitative science justification and comparison • Assess importance of thermal infrared • Define the telescope emissivity requirements • Set PSF requirements for stray light, diffraction wings, etc

33. Tasks for working groups-2 • Enclosure and building • Write a report for CoDR on potential enclosure design • Write a report for CoDR on potential support building requirements and design • Science instruments • Write a report for CoDR on potential science instruments (AO on, AO off) • Strawman designs with performance, size, cost • Define the telescope emissivity requirements • Assess value of baffles in telescope

34. Tasks for working groups-3 • Adaptive Optics • Write a report for CoDR on potential AO modes and designs • (see Dekany status report) • Telescope • Design telescope • Write a report for CoDR on details of telescope design and performance