Residual Risk Assessment at Delivery – Delta from PSR

1. Residual Risk Assessment Residual Risk Assessment at Delivery – Delta from PSR Jeff Radwick OMPS Project Engineer/Risk Manager

2. Agenda Residual Risk Assessment • Risk Scoring Criteria • Was-Is Matrix (with waivers) • Was-Is Table (with waivers) • Yellow Risk Charts • FM2 Impact on PFM Residual Risk

3. Risk Scoring Criteria Risk Management EID – End-Item Delivery IPD – IPT Product Delivery Risks discussed today are technical risks

4. Residual Risk Summary Residual Risk Assessment Was at PSR Is at Delta-PSR 13 1 2 1 2 1 1 1 1 1 1 1 4 1 8 4 2 • The delta in number is due almost solely to approved waivers • They predominantly are of negligible risk factor score (RFS) • The trend globally is down and to the left, indicating an improved risk picture from that presented at PSR

5. Residual Risk Summary Residual Risk Assessment - No change in status from PSR

6. Residual Risk Summary Residual Risk Assessment

7. Residual Risk Summary Residual Risk Assessment

8. Residual Risk # 1: EMI / EMC Performance Residual Risk Assessment Residual Mission Risk

9. Residual Risk # 2: Radiation Effects on CCDs Residual Risk Assessment Residual Mission Risk

10. Residual Risk # 8: Weak Bit in Hitachi EEPROMs in Single Board Computer Residual Risk Assessment Residual Mission Risk

11. Residual Risk # 22: MGSE Design Safety Factors Residual Risk Assessment Residual Mission Risk

12. Other Residual Risks to the Mission Residual Risk Assessment • Stray Light on Nadir Sensor (3,3) or (1,2) • NPP stray light sources will be seen by Nadir instrument during on-orbit calibrations • Waiver submitted communicates the need to add black Kapton tape to sun sensor mast on NPP to the next level of integration • Diffuse scatter test (glint test) successfully completed • Risk factor score is a 9 if NPP mitigation is not done

13. FM2 Impact on PFM Residual Risk Residual Risk Assessment • BATC OMPS conducted an assessment of FM2 design changes and their impact to the PFM residual risk at delivery • All FM2 design changes are the result of process and/or design improvements derived as result of the experience gained on the PFM. • These are summarized in the backup slides • Technical (performance) risks are derived from requirements • If a non-compliance on the PFM drove the change on FM2, a waiver was submitted and approved • Therefore BATC-OMPS concludes that FM2 changes do not cause any change to the PFM residual risk state at delivery

14. The OMPS PFM residual risk at delivery is assessed to be low-moderate Risk Summary & Recommendation Residual Risk Assessment • All risks are understood and mitigation plans are either completed or addressed during sell-off / waiver process

15. Residual Risk Assessment Backup Slides

16. Nadir Design Changes for FM2 Are Primarily Based on PFM Lessons Learned OMPS Delta PSR • Mechanical Design Changes • Changed NP mechanical design to match Code V model (address salvage EO) • Changed interface for optical mounts to spherical washers on spherical seats (boresight FRB) • Changed TC spectrometer slit from bonded to clamped assembly (reduce thermal “puckering”) • Changed sunshade design (mitigate glint issue) • Added relief to LED housing (prevent shorting) • Changed to finer grind on aluminum diffusers (improved diffuser BRDF) • Changed diffuser mount to external (allows diffuser replacement without telescope disassembly) • Added board stiffeners to FPA PWA (reduce flexing in vibration environments) • Optical Design Changes • Minor improvements to stray light and light leak • Changed coating on fused silica optical cubes from chrome to aluminum (meet 80% requirement) • Electrical Design Changes • Reduced use of Tiodize and added grounding straps (EMI/EMC mitigation) • Added insulation pad underneath thermostats (prevent shorting) • Added twisting/shielding to FPA temp sense diode wiring and change routing (EMI/EMC mitigation) • Minor changes in FPA PWA design (improved full well performance) • NPOESS Specific Design Changes • Additional optical cube with 15-deg rotation for NPOESS (at NGST request)

17. MEB Design Changes for FM2 Are Based on PFM Lessons Learned and De-Manifest of Limb Sensor OMPS Delta PSR • Mechanical Design Changes • Reduced diameter of cable harness support bars (allows MLI to lay more flush with top of MEB) • Minor changes to MEB mounting spacers (facilitate easier AI&T) • Electrical Design Changes • Modified survival heater wiring (to meet MEB spec) • Added resistors across MEB thermostats (eliminate floating wires) • Motherboard: added 1 white wire (allows MEB to process NP housing temp sensor) • Motherboard: remove 1553 transformer center tap chassis ground (proposed) • Nadir T&C: removed common mode chokes in CCD bias rails (reduces rail sag while clocking) • Nadir SP: changed filter caps and added .5 ohm in series with tantalum caps (improved stability) • LVPS1: changed linear regulators (increase margin on WCA) • LVPS2: lowered temperature on Vref & added test point isolation resistors (temperature de-rating) • NPOESS Specific Design Changes • Limb T&C and SP: changed to Limb replacement board (provides signal termination) • Added dust covers and associated hardware to unused connectors • Revised cable routing and added cable harness routing supports • Modified chassis surface finish (to meet NPOESS thermal requirements)