THEMIS Instrument CDR 1 UCB, April , 2004 EFI Axial Booms Thermal Christopher Smith Thermal Engineer

THEMIS Instrument CDR 2 UCB, April , 2004 Axial Boom Stowed Axial Boom (AXB) Two units mount inside a carbon fiber tube centrally mounted on the probe Tube attached to the top deck through an aluminum flange that is bare bolted Bare bolted to lower deck Two stacers, one from each unit, deploy out the tube ends AXB Mounting Tube Single AXB unit

THEMIS Instrument CDR 3 UCB, April , 2004 AXB  /  Map 80% Alum Foil Tape 20% Bare Carbon Fiber Bare Carbon Fiber Alodined Aluminum VDA Tape

THEMIS Instrument CDR 4 UCB, April , 2004 AXB Model Inputs Optical materials –Aluminum Foil Tape –Bare Carbon Fiber –Alodined Aluminum Thermophysical materials –Aluminum, 6061 –K13D2U Carbon Fiber –T300 Carbon Fiber Heaters –None used at this time, though we are prepared to supply deployment heaters if needed Conductors –Bare bolted top flange to deck: W/C inc. bolts, flange, and adhesive –Bare bolted bottom flange to deck: 3.3 W/C each, 20 W/C total –Bare bolted AXB to Tube mount: 0.79 W/C each, total Power Dissipation –0 Watts AXB Mounting Tab

THEMIS Instrument CDR 5 UCB, April , 2004 AXB Case sets Bottom to sun a cold case boundary condition has no eclipse All above cases run separately with stowed boom and deployed boom

THEMIS Instrument CDR 6 UCB, April , 2004 AXB Mechanical Unit Standard Plots - Deployed

THEMIS Instrument CDR 7 UCB, April , 2004 AXB Mechanical Unit Sunline Plots - Deployed

THEMIS Instrument CDR 8 UCB, April , 2004 AXB Mechanical Unit Standard Plots - Stowed

THEMIS Instrument CDR 9 UCB, April , 2004 AXB Mechanical Unit Sunline Plots - Stowed

THEMIS Instrument CDR 10 UCB, April , 2004 AXB Results Table

THEMIS Instrument CDR 11 UCB, April , 2004 AXB Mounting Tube Modifications Spacecraft was consuming too much power in the coldest, but nominal, science case ~2.2 W To help mitigate this issue two modifications are being considered for the AXB Mounting tube Tube construction switched from all T300 ( 5 W/mK) fiber to 4 plys K13D2U (500 W/mK) + 2 plys T300 Tube exterior changed from blanket to a mix of Foil tape and bare carbon Current results show the AXB unit getting too hot and we are currently exploring options to cool it down Increase isolation between AXBs and tube Isolate tube flange from top deck At worst, cool the tube down by reducing the percentage of foil tape When the design is complete it will be within limits though new temperatures may require the thermal vac hot deploy test be repeated at a new higher temperature

THEMIS Instrument CDR 12 UCB, April , 2004 AXB Temp Map for Hottest Case

THEMIS Instrument CDR 13 UCB, April , 2004 AXB Temp Map for Coldest Case

THEMIS Instrument CDR 14 UCB, April , 2004 Axial Boom Deployed AXB “can” AXB PreAmp Exposed Bit After Deploy

THEMIS Instrument CDR 15 UCB, April , 2004 AXB Geometry Model Deployed Stacer Model

THEMIS Instrument CDR 16 UCB, April , 2004 AXB Deployed Elements  /  Map DAG 154Alodined Aluminum DAG 213 Bronze

THEMIS Instrument CDR 17 UCB, April , 2004 AXB Model Inputs Optical materials –Acheson Coloids DAG 213 (2 part) –Acheson Coloids DAG 154 –Alodined Aluminum –Bronze Thermophysical materials –Aluminum, 6061 –Bronze –Elgiloy –PEEK Heaters –None Conductors –Main Stacer to Tip Piece, 1 rivet and circumferential contact,.3 < G <.9 W/C –Tip Piece To Bronze DDAD Lock, Large threaded interface, 10 W/C –DDAD Lock to PreAmp, large threaded bolt 3.57 W/C –PreAmp to Mini Stacer, 1 rivet and circumferential contact.3< G <.8 W/C –Mini Stacer to Can, 1 rivet, 0.3 W/C Power Dissipation –0.07 Watts Nominal at Preamp AXB Preamp

THEMIS Instrument CDR 18 UCB, April , 2004 AXB Deployed Elements Case Sets Top and Bottom to sun cases after deployment are limited to no less than 11 degrees off the sun line The Model for the Top and Bottom to Sun cases goes through a 180 min eclipse. A 100 min eclipse is the actual limit and is shown in plots

THEMIS Instrument CDR 19 UCB, April , 2004 AXB Boom Elements Standard Plots - Deployed

THEMIS Instrument CDR 20 UCB, April , 2004 AXB Boom Elements Sunline Plots - Deployed

THEMIS Instrument CDR 21 UCB, April , 2004 AXB Preamp Results Table Science operation limited to a 36 min eclipse Current predicts show Preamp falling below the limit on the TO99 can.

THEMIS Instrument CDR 22 UCB, April , 2004 AXB Preamp Qualification AXB Preamp model is currently a simple lump with the proper radiative surfaces Thermal isolation of the TO-99 from the outer shell is complicated and difficult to reliably model Thermal Vacuum test planned determine the thermal isolation of the TO-99 from the preamp outer surface (April 12 th – April 23 rd ) This thermal isolation determined by test will be input into the thermal model to determine a reliable qualification temperature, still likely to be under the current qualified temp of –65

THEMIS Instrument CDR 23 UCB, April , 2004 AXB Preamp Models

THEMIS Instrument CDR 24 UCB, April , 2004 EFI Spin Plane Booms Thermal Christopher Smith Thermal Engineer

THEMIS Instrument CDR 25 UCB, April , 2004 SPB 4 separate units mounted to the bottom deck Snout pokes out the solar panel Sphere and Preamp deploy out the snout on a wire (Half Sphere shown in picture) Sphere and preamp separate as rotation unwinds a thin wire from a spring loaded wheel

THEMIS Instrument CDR 26 UCB, April , 2004 SPB  /  Map AZ 2000 IECW Inorganic White Paint MLI Alodined Aluminum

THEMIS Instrument CDR 27 UCB, April , 2004 SPB Model Inputs Optical materials –Germanium Black Kapton (Sheldahl 275XC Black Kapton) –Alodined Aluminum –AZ 2000 IECW Inorganic White Paint –Blanket:.01 <  <.05 Thermophysical materials –Aluminum, 6061 –ULTEM Heaters –None used at this time, though we are prepared to supply deployment heaters if needed Conductors –1/8” Ultem isolators for top deck: 0.01 W/C each, 0.04 W/C total Power Dissipation –0 Watts

THEMIS Instrument CDR 28 UCB, April , 2004 SPB Case Sets

THEMIS Instrument CDR 29 UCB, April , 2004 SPB Mechanical Unit Standard Plots

THEMIS Instrument CDR 30 UCB, April , 2004 SPB Mechanical Unit Sunline Plots

THEMIS Instrument CDR 31 UCB, April , 2004 SPB Results Table

THEMIS Instrument CDR 32 UCB, April , 2004 SPB Heat Map for Coldest Case

THEMIS Instrument CDR 33 UCB, April , 2004 SPB Heat Map for Hottest Case

THEMIS Instrument CDR 34 UCB, April , 2004 SPB Deployed Elements Preamp and sphere are connected by a thin wire Preamp is connected to SPB deployment unit by another wire Preamp is nearly identical to Axial version Sphere is only a mechanical element Titanium Nitride DAG 213

THEMIS Instrument CDR 35 UCB, April , 2004 Preamp and Sphere Analysis

THEMIS Instrument CDR 36 UCB, April , 2004 SPB Sphere and Preamp Model Nodes 3 and 4 are for the sphere hot and cold cases Nodes 5 and 6 are for the preamp hot and cold cases As with the axial preamp the SPB preamp falls below its limit by a bit. Qualification plan is in the works

THEMIS Instrument CDR 37 UCB, April , 2004 SPB Sphere and Preamp Plot