NIRSpec Status and PDR Results Jeff Valenti & Mike Regan 2006 March 16 TIPS/JIM

Light Path

PDR Objectives Assess compliance with requirements Assess NIRSpec system specifications Assess external interface definitions Integrated Science Instrument Module Microshutter Array Detector Subsystem Assess predicted NIRSpec performance Assess cost, schedule, and risk estimates

PDR Format Board Led by ESA with NASA participation Co-chaired by NASA Independent Review Office Technical Panels System Structure, thermal, and mechanisms Optics Electrical and software Product Assurance Programmatic Panel

PDR Timeline Dec 1 Documents delivered Dec 2 Kick-off meeting held … Panel meetings … Jan 6 Panel chairs met “Review Item Dispositions” submitted Jan 31-Feb 2 Co-location ESA/Industry ESA/Instrument Science Team Feb 9 Panel chairs reported to board Feb 15 Board met

PDR Verdict NIRSpec PASSED its PDR!

PDR Major Findings Microshutter technology is a risk Electrostatic discharge is a risk Create stray light control plan Include detector in EMC control plan Cool light sources used in ground tests Prevent contamination by water Manage target acquisition interfaces Test cold after observatory integration

No Schedule Change JWST launch date slipped to June 2013 NIRSpec delivery date is unchanged Necessary to control ESA costs Requires timely definition of interfaces Requires timely delivery of subsystems NASA funding ISIM to support schedule

Microshutter Update Technology demonstration tests Lifetime test: <5% shutters fail after 10 5 cycles Acoustic test: <1% shutters fail Vibration test: <1% shutters fail Radiation test: <1% shutters fail Open/closed contrast: >2000 EMC/EMI test Demonstrate ability to plug shutters in lab Stiction issue 0.5% shutter stuck open after 10 5 cycles Heating to 300 K causes shutter release

Rogue Path Update Unbaffled telescope Sky skirts FSM and illuminates POM NIRSpec wants 9 mm increase in FSM mask NIRCam coronagraph blocked by >6 mm Outer edge of FSM mask Inner edge of NIRSpec mask

Orders of Magnitude in Scale 10  4  365  K Shutters Q1 Q2 Q3 Q4

Plate Scale Changes We must position targets in shutters Allocate 5 mas for plate scale changes Corresponds to 0.01% change in focal length Rephase primary as often as once a week