1. TIPS - October 18 2007 Updates on ACS-R Marco Sirianni October 18, 2007

2. TIPS - October 18 2007 Agenda ACS Status ACS-R –Concept –Schedule –EVA activities –Role of STScI

3. TIPS - October 18 2007 Status of ACS oACS Side 1 Failed on June 19, 2006 The ARB identified a most probable candidate for the failure, an Interpoint DC-DC Converter on LVPS 3 board in MEB1 Precluded all WFC and HRC CCD imaging. Operations started on side-2 electronics on Jul 4 2006. oACS Side 2 failed on January 27, 2007 Short likely in the Hold Bus Side-2 is completely inoperable Side-2 is inaccessible to astronauts for repair Side 2 is not part of repair mission oACS was configured for Side-1 SBC operations only on February 15, 2007

4. TIPS - October 18 2007 ACS-R Immediately after the failure of Jan 2007 the HST project assembled a team for the repair of ACS. At the end of February a specific option was select for further study. On October 3 & 4 the ACS-R project passed the critical design review.

5. TIPS - October 18 2007 ACS-R CDR NameAffiliationPrimary Disciplines Dennis DillmanNASA/NESCReview Team Chair Tom AkersConsultantEVA John GrunsfeldJSC Crew OfficeSTS-125 Crew Richard HarmsHST SM4 SRBInstrument Systems Denny HoltConsultantShuttle Mission Mgmt Chris IannelloKSC EngineeringPower Systems Wes OusleyGSFC AETDThermal Engineering Joe PellicciottiGSFC AETDMechanical Systems Pete SalernoGSFC SROElectrical Systems Steve ScottGSFC Chief EngineerSystems, C&DH, SW

6. TIPS - October 18 2007 ACS-R Team

7. TIPS - October 18 2007 LVPS H MEB Side 1 APB LVPS O LVPS H MEB Side 2 APB LVPS O HOLD Bus OPERATE Bus Failed Element Suspect Element PDU 20 Amp Fuse OPERATE Bus HOLD Bus PDU 20 Amp Fuse Side 1 is fully operational except for the LVPS power to the CEBs. Currently running on Side 1. Side 1 is fully operational except for the LVPS power to the CEBs. Currently running on Side 1. Side 2 is inoperable. +15, -15, +35 +5 +15, -15, +35 +5 WFC CEB WFC CCD HRC CEB HRC CCD ACS Current state simplified Electrical Block Diagram

8. TIPS - October 18 2007 ACS-R concept Restore WFC functionality under side-1 (LVPS failed on 6/2006) by replacing the WFC CEB cards with a new module (CEB-R) powered by a new LVPS (LVPS-R) Restore HRC functionality by backpowering the existing HRC CEB (the success depends on the status of the existing wire harness within ACS) Requirement: do not harm SBC

9. TIPS - October 18 2007 ACS-R simplified Electrical Block Diagram LVPS H MEB Side 1 APB LVPS O LVPS H MEB Side 2 APB LVPS O HOLD Bus OPERATE Bus Failed Element Suspect Element PDU 20 Amp Fuse OPERATE Bus HOLD Bus PDU 20 Amp Fuse Side 1 used to operate the entire instrument except for the CEBs which are replaced/powered by a new box. Side 2 is inoperable. +15, -15, +35 +5 +15, -15, +35 +5 New CEB WFC CCD HRC CEB HRC CCD New Element New Power Supply

10. TIPS - October 18 2007 ACS-R Design Concept PIE = Power Intercept Element CEB-R = CCD Electronic Box - Repair LVPS-R= Low Voltage Power Supply - Repair POE = Power Output Element PIE = Power Intercept Element CEB-R = CCD Electronic Box - Repair LVPS-R= Low Voltage Power Supply - Repair POE = Power Output Element PIE LVPS-R POE CEB-R

11. TIPS - October 18 2007 CEB Astronaut Handrail Electrical Interface Conector

12. TIPS - October 18 2007 CEB-R Replace the original 4 boards with a new element which contains 4 replacement boards Backplane Timing Board Clock B/Y Board Clock A/X Board ASPC/Bias Board Motherboard Mating Connectors

13. TIPS - October 18 2007 LVPS-R ACS HandrailHandrail Post Post Attachment Clamp Tether Ring Grounding Plug PIE Connector Cover with Tether Ring POE Cable Stowing

14. TIPS - October 18 2007 HRC Backpowering The ACS-R design provides the option of backpowering the existing HRC CEB through the existing harness within the instrument. One of the main issue is the supply of the +35V. If it can be provided by the original LVPS than it will be sincronized (-> lower noise), but it must be provided by the LVPS-R HRC could be noisier. Preliminary tests with flight spare HRC CEB and CCD show no difference

15. TIPS - October 18 2007 ACS-R Testing Besides the single component testing the full ACS-R system will be tested with: Flight spare HRC CEB (backpowering testing) Flight spare build for HRC and WFC –Cannot be cooled as on-orbit –Used for testing with hi-I preamp and detector –Functional testing when lowest noise is not needed WFC SITE spare CCDs (+custom cryostat) –Can be cooled to -80 C, crosstalk testing CCD emulator – allows readout of a complete 4Kx4K image –adjustable noise level: Match on-orbit detector level to determine expected performance Set noise level very low to verify noise contribution of CEB-R Set noise level high to optimize timing pattern and CDS for best results.

16. TIPS - October 18 2007 Schedule Highlights Testing with the first engineering module of CEB-R and ACS flight spare CCDs will start on Oct 25th. Flight LVPS ready Mid Jan Flight CEB-R ready early March Servicing Mission Ground Testing (SMGT) End of February (possibly a second campaign with complete flight-hardware) TV testing - April Shipment to KSC - Jun 9 Launch - August 8

17. TIPS - October 18 2007 More Detailed Schedule ACS Repair System Integration ACS-R Functional Test ACS-R T/V Test Mechanical Interface Verifications CEB Test Set ACS-R Performance Test ACS-R EMI Test CEB Test Set VEST Performance Test Envelope Metrology HFMS Fit-Check Carrier Fit-Checks Crew Fams CEB Test Set EICIT/IVT Tests CEB Test Set ACS Spare Detector Kirby Cryostat/CCDs CEB Test Set ACS Spare Detector T/V Test Fixture VEST/Ops Bench CCD Emulator SM4 System Compatibility Test VEST/Ops Bench CCD Emulator Ship to Launch Site 2/21 – 2/25/082/26 – 2/28/082/29 – 3/6/083/7 – 3/20/083/21 – 4/17/08 SM4 Mission Timeline Test 4/15 – 4/18/08 ACS Repair SMGT VEST/Ops Bench CCD Emulator VEST/Ops Bench CCD Emulator 5/13 – 5/14/08 System I&T Tests using EM ACS Repair System hardware: 4/29 – 5/5/084/22 – 4/28/08 2/27 – 2/28/08 Deliver to I&T ACS Repair VEST Tests VEST/Ops Bench CCD Emulator EICIT/IVT AT/FT SFT 4/21/08 ACS-R Pre-Ship Performance Test 5/16 – 5/22/08 1/31 – 2/14/08 CEB Test Set ACS Spare Detector Kirby Cryostat/CCDs

18. TIPS - October 18 2007 Current Timeline

19. TIPS - October 18 2007 EVA Tasks All ACS Repair EVA tasks have been evaluated by suited SM4 crew ACS Prep 00:05 Install Guide Studs 00:20 Remove the EMI Grid 00:10  Install grid cutter, actuate, remove grid cutter w/grid Remove WFC Access Cover Plate and CEB Top Plate 00:45  Install FCP, release fasteners, remove FCP Remove 4 WFC CEB electronic boards 01:00 Install WFC CEB Replacement Module 00:10 Install Power Supply Module to ACS handrail, mate PIE connector to LVPS-R and POE connector to CEB-R00:10 ACS worksite clean-up 00:20 Total (w/o door operations) 03:00 The EVA timeline will continue to be refined through upcoming scheduled NBL crew training and test runs as well as 1-G activities to address open issues on tool stowage, tool design, fastener access, etc.

20. TIPS - October 18 2007 EVA Tools Screen Grid Cutter Fastener Capture Plate Card Extraction Tool

21. TIPS - October 18 2007 The role of STScI Support ground calibration to identify areas where science operations may need modification (commanding, proposal preparation, data processing) Support IPT in the definition of the ACS-R AT/FT Support the scientific evaluation of the FT SMOV planning and on-orbit re-commissioning

22. TIPS - October 18 2007 ACS-R in SMOV ACS-06 CCD Functional Test\ ACS-08 WFC CCD Cross Talk SMOV WFC and HRC observations will be kept in separate proposals/visits to facilitate operations in case of unforeseen problems with the HRC backpowering. Cycle 17 calibration programs will overlap with SMOV and will provide further characterization of the instrument. We will include, as part of cycle 17 calibration plan, a “CCD optimization” program to investigate the benefits of operating the CCDs with a reduced clocking rate and clamp and sample scheme. The full impact on science operation (read noise, CTE, dynamic range, readout time) will be evaluated before making new options available for GO science. This program will be executed promptly if the noise characteristics of the default configuration are not satisfactory.

23. TIPS - October 18 2007 Conclusion ACS-R successfully passed CDR More integrated testing will start soon STScI will be more involved in the future starting with the ground testing -----Original Message----- From: Weiss, Mike Sent: Thursday, October 04, 2007 10:33 PM To: Smith, Hsiao Subject: Way to Go! The ACS Repair just pulled off a miracle! You should all feel extremely proud of what you just accomplished, and I'm sure that you do. Please pass on to Ed, Pete and the entire team gratitude from not only the HST Program Office but from anyone in our Agency who may feel that NASA no longer has the "Right Stuff." ACS Repair has just proved them wrong. Superb effort on the part of all! Mike