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Particles and Fields Package Peer Review, SSL May 10, 2010. Christopher Smith Thermal . Responsibilities. UCB builds individual instrument thermal models SWIA, SEP, LPW, PFDPU UCB and Goddard (John Hawk) currently both working on SWEA. Will transition to UCB only.
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Particles and Fields Package Peer Review, SSL May 10, 2010 Christopher Smith Thermal
Responsibilities UCB builds individual instrument thermal models SWIA, SEP, LPW, PFDPU UCB and Goddard (John Hawk) currently both working on SWEA. Will transition to UCB only. UCB submits these models to LM who incorporates them into the spacecraft thermal model. LM generates sink couplings for each instrument node for environments and delivers these to UCB UCB incorporates LM environments and goes through a design cycle to meet ERD requirements. UCB returns new generation of instrument models to LM. Cycle repeats as necessary LM responsible for producing official predicts for mission First predicts and environments scheduled to be complete for PDR
UCB Plan This method is cumbersome and does not allow UCB to quickly and easily analyze design changes. Also may generate incomplete identification of individual instrument worst cases. The best option is to take delivery of the entire spacecraft model from LM and run full model here but LM not fond of the idea In the meantime UCB will generated a boundary node spacecraft and environments to run here. Goal is to complete a more realistic design cycle here
Current Status Complete Paul Turin did early work with a spreadsheet to choose coatings given Aero and Thruster flux Initial instrument models delivered to LM in April Completed building boundary node spacecraft To do before PDR Complete environments for boundary node spacecraft Earth Orbit, Mars Orbit complete Need to complete Deep Dip heating and Thrusters heating Complete identification of worst cases and complete compliant design Generate heater predicts Receive environmental loads from LM and initial predicts from LM
ERD Highlights 1 Solar Flux at 1 AU At Earth: 1400 to (1290?) to 0 W Solar, 0 to .32 Albedo, 0 to 270 Planetary IR Cruise: 0 1414 W Solar Mars: 0 to 490 to 410 W Solar, .18 to .35 Albedo by latitude, -125 to 25 C Planetary IR Deep Dip Heating “Aerothermalheating rates for deep dip science operations shall be assumed to be a constant 0.1 W/cm2 (worst case/fully margined) for a 10 minute drag duration. It should be assumed that the aeroheating flux may impinge on the spacecraft from any direction (with respect to the spacecraft body axes) for the entire drag duration.” Approximately 1 sun, 1000 W/m2 , given other worst case assumption, and depending on final design, PFDPU may get sun and aeroheating on radiator surface for ~10min
ERD Highlights 2 200 failure free vacuum operations, minimum 48 hrs hot, 72 cold 8 cycles total per component over all TVAC testing, minimum of 4 at component level. Minimum of 12 hrs operating at each hot and cold Thermal balance called out for SWIA and STATIC Thermally Isolate Instruments Design for deck temperatures of -50 to 50
Optical Properties • All Materials approved by GSFC and JPL on previous missions • Clear Alodine done by one plater with specified soak time. Extensive sampling with THEMIS. Occasional sampling with other missions. Wide BOL/EOL variance assumed in design
Thermal Limits and Margins “Predicts” at least +/- 5 from model predictions Flight Acceptance +/- 5 from Predicts Protoflight / Qual +/- 10 from Predicts
SWIA Thermal Model Germanium Black Kapton Blanket DAG 213 Power Disipation: 1.48 W +/- 15% Mass: 2.03 kg Blanket Conduction to SC Isolated 4 #8 Titanium with .25" G10 Isolator = .013 W/C each
STATIC Thermal Model Blanket DAG 213 Power Disipation: 3.98 W +/- 15% Mass: 2.33 kg Blanket Conduction to SC Isolated 4 #8 Titanium with .25" G10 Isolator = .013 W/C each
SWEA Thermal Model Blanket DAG 213 Power Disipation: .867 W +/- 15% Mass: 1.64 kg SC Balance Mass: ~ 20 kg Blanket Conduction to SC Isolated 4 #8 Titanium with .25" G10 Isolator = .013 W/C each
SEP Thermal Model Silver Teflon Ebanol C Black Body Power Disipation: .015 W +/- 15% Mass: .687 kg Clear Alodine Conduction to SC Isolated 4 #8 Titanium with .25" G10 Isolator = .013 W/C each
PFDPU Thermal Model Blanket Power Disipation: 11.5 W +/- 15% Mass: 4.78 kg Conduction to SC Isolated 6 #8 Titanium with .25" G10 Isolator = .013 W/C each Black Anodize
STATIC Thermal Model Stowed Stowed Stacer and DAD PreAmp Power: .015 W +/- 15% Mass: 2.31kg Bit light of 2.9 in resource table Rod Caging Mechanism Base Mech: 6 #8 Ti with .25" G10 Isolator = .013 W/C each Cage: 4 #8 Ti with .25" G10 Isolator = .013 W/C each
STATIC Thermal Model Deployed Clear Alodine DAG 213 Titanium Nitride
Spacecraft Boundary Model Solar Arrays -145 to 145 C MLI Unbound All Panels and Gussets -50 to +50 C
Components Installed On SC SEE TD MODEL