SPP Fields Antenna TRL6 Review Pre-PDR Mechanical Design Jeremy McCauley SSL UCB 7/18/2013 Current Configuration: SPP Spacecraft FIELDS, SPP-ANT-MEC-000 Antenna Assy

TRL6 Development Stowed along SC for Launch – Support at ends and midspan – Angled to fit on panels TRL6 Development Tasks Verify dynamic response Stowed along SC for Launch – Support at ends and midspan – Angled to fit on panels TRL6 Development Tasks Verify dynamic response

Whip Vibe Restrained as designed: – One end fixed, mid point clamped, end fork – Bent to match Stowed configuration First Resonant Frequency: 6 to 10 Hz No permanent deformations or distortions Restrained as designed: – One end fixed, mid point clamped, end fork – Bent to match Stowed configuration First Resonant Frequency: 6 to 10 Hz No permanent deformations or distortions

Backup Slides Current Configuration: SPP Spacecraft FIELDS, SPP-ANT-MEC-000 Antenna Assy

Sep. 23, 2012 SPP FIELDS Meeting Agenda TRL6 Development Tasks Mechanical Design Thermal Design BB Tests

Design Concept Equal exposed length Coplanar with TPS Greatest length, greatest separation Stowed along SC for Launch Preamp located as close to ANT as possible

Design Development Hinge – Similar to THEMIS FGB designed at SSL – Behind TPS at ordinary flight environments – Mounting accomodation worked with APL Hinge – Similar to THEMIS FGB designed at SSL – Behind TPS at ordinary flight environments – Mounting accomodation worked with APL

Design Development Outboard Segment – Exposed to intense sunlight – Shield and Isolate to provide quick thermal cooling Outboard Segment – Exposed to intense sunlight – Shield and Isolate to provide quick thermal cooling

Thermal Design Concept Hinge and Preamp Behind TPS Whip >1300 C Thermal Choke Shield for Stub Shield from TPS Radiator for Preamp Hinge and Preamp Behind TPS Whip >1300 C Thermal Choke Shield for Stub Shield from TPS Radiator for Preamp Thermal Choke TPS

Thermal Design Concept Sapphire Isolators on Whip, Stub and Shield – (APL Data) Alumina inside Stub FR4 or similar all other places Titanium Mounting Foot Sapphire Isolators on Whip, Stub and Shield – (APL Data) Alumina inside Stub FR4 or similar all other places Titanium Mounting Foot  Model

BB Testing Thermal Isolators and Shield – PROMES – SAO – GSFC Whip Vibe FWB Hinge and Stub Cage Thermal Isolators and Shield – PROMES – SAO – GSFC Whip Vibe FWB Hinge and Stub Cage

Sep. 23, 2012 SPP FIELDS Meeting Thermal Choke TTM Whip Disk Whip Choke Choke Water Cooling

Sep. 23, 2012 SPP FIELDS Meeting TTM Choke Thermal Results Thermal Balance

Sep. 23, 2012 SPP FIELDS Meeting Thermal Shield TTM Shield Clamp Bracket Stub Water Cooled

Sep. 23, 2012 SPP FIELDS Meeting TTM Shield Thermal Results Thermal Balance

Sep. 23, 2012 SPP FIELDS Meeting TTM Shield Lessons Learned Re-crystalization of Titanium – Has no observed effect on bracket Melting of silver coating on bolts – Might create gaps on joints Rapid heating – Probably deformed shield

Thermal Distortion Testing 28 inch sample ~10 inch heated section Monitor motion of tip – Max deflection ~0.06” Larger than desired 28 inch sample ~10 inch heated section Monitor motion of tip – Max deflection ~0.06” Larger than desired

Thermal Design Conclusions Niobium good for temperatures – Distortion to be characterized before PDR Thermal Choke works Shield for Stub gives sufficient isolation A286 Screws – No Silver – To be verified with static furnace test over the next month Niobium good for temperatures – Distortion to be characterized before PDR Thermal Choke works Shield for Stub gives sufficient isolation A286 Screws – No Silver – To be verified with static furnace test over the next month

Whip Vibe Anomaly End Bent at Fork – No contact from personnel observed – Transverse to fork when found – Most likely due to fixture during resonant case First Y-axis random Ejected test article – Test rerun for verification End Bent at Fork – No contact from personnel observed – Transverse to fork when found – Most likely due to fixture during resonant case First Y-axis random Ejected test article – Test rerun for verification

FWB and Hinge Testing Testing FWB for torque over temperature range – Second Generation – Ambient Torque Testing verified function as desired Testing Hinge Form and Function Already TRL6 due to previous Flight Designs Testing FWB for torque over temperature range – Second Generation – Ambient Torque Testing verified function as desired Testing Hinge Form and Function Already TRL6 due to previous Flight Designs

TRL6 Conclusions Materials – a/e data complete – Insulators chosen Thermal response – Choke, shield work – Screw material in final test – Tube distortion in testing – SAO Beam testing next month 2 (later 6) beams Dynamic response Materials – a/e data complete – Insulators chosen Thermal response – Choke, shield work – Screw material in final test – Tube distortion in testing – SAO Beam testing next month 2 (later 6) beams Dynamic response TRL6 by PDR