FIELDS SPP meeting Thermal MLI requirements

Publish in



Please download to get full document.

View again

of 12
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
FIELDS SPP meeting Thermal MLI requirements. G.K.Martin 2013-06-26. SPP Observatory Thermal Overview. Thermal Protection System (TPS) Shields the S/C from the sun during closest approach Transition Structure Assembly (TSA) Conductively isolates the S/C from the TPS Solar arrays
FIELDS SPP meetingThermalMLI requirements G.K.Martin 2013-06-26 SPP Observatory Thermal Overview Thermal Protection System (TPS)
  • Shields the S/C from the sun during closest approach Transition Structure Assembly (TSA)
  • Conductively isolates the S/C from the TPS Solar arrays
  • Two DOF to track the sun (PPT) and move through the umbra & penumbra for optimum solar load CSPR panels
  • Dissipates heat via a water cooled pump system to maintain thermal heatload on solar arrays Barrier blanket
  • Thermal blanket suspended above the top of the S/C that radiatively decouples the backside of the TPS from S/C components Spacecraft
  • Internal heat sharing within S/C design
  • MLI is stood off 2”
  • Aluminum facesheets
  • Louvers on S/C body
  • Conductively isolated to instruments via bracket
  • Radiatively view to instruments is TBR on individual basis (currently radiatively isolated)
  • Unless otherwise noted, the components described have a negligible radiative (no conductive) coupling between TPS & S/C mounted instruments MLI Requirements
  • ICD
  • TheInstrument to observatory MLI blanket interface is the joint responsibility of the Instrument IDT and JHU/APL. Design details will be developed cooperatively.
  • Blanket interfaces shall be captured in the mechanical drawing, with adequate closeout to the spacecraft blankets, and include mechanical tie downs and/or closeout locations [INST_067].
  • The Instrument IDT is responsible for MLI fabrication and installation, unless other arrangements have been made with the spacecraft thermal engineer.
  • The Instrument surfaces with blankets shall have a minimum clearance of 0.635 centimeters from all other surfaces [INST_068].
  • Blanket venting requirements are TBD.
  • External blanket surface electrical resistivity is required to meet the requirements established in the EMECP. The size of all non-conductive areas shall be reported to the JHU/APL system engineer [INST_069]. Approval of non-conductive areas requires approval of JHU/APL in view of electrostatic requirements. At least two (unless otherwise agreed) grounding straps shall be provided for each thermal blanket to meet observatory-level electrostatic requirements installed by the Instrument team [INST_070]. The spacecraft thermal team shall provide ground straps for the Instrument. Ground strap details will be included on the instrument specific ICD.
  • Instrumentsinternal to the spacecraft bus shall not be blanketed [INST_071].
  • Other
  • Components exposed to temperatures > 150°C requires high temperature MLI (S/C mounted instruments do not fall under this category)
  • Instrument shall have an MLI attachment location for S/C blanket close-outs (mechanical requirement)
  • Labor costs for APL built blankets is the instrument responsibility
  • MLI Clearance Requirements 0.25” INSTRUMENT INSTRUMENT Close-out for S/C blanket Clearance required from instrument surface with MLI to any adjoining surface is 0.25” Instrument shall design a mechanical close-out for the S/C blanket interface FIELDS MLI LocationAntenna Preamps and Hinges Antenna preamps MLI (high temperature) on box only, 5 of 6 sides Quantity: 4 (each test & flight) Antenna hinges MLI (high temperature) Quantity: 4 (each test & flight) FIELDS MLI LocationFGMs, SCM MLI on all 3 sensors
  • Lay-up = mylar-dacron (15 to 17 layers)
  • (MAYBE high temperature layup, TBD)
  • GSFC will provide FGM blankets
  • APL is responsible for any boom blankets
  • APL Estimate for FIELDS blankets APL MLI Building Process
  • For teams that APL is building blankets
  • Sent quotes to PM
  • Verify delivery dates
  • Will meet requirements/work together
  • APL blanketing process
  • Build rapid prototype (in quote)
  • Build MLI template
  • MLI drawings (lay-ups)
  • Build test blankets
  • Modify test blanket template for flight blankets
  • Information required from each team
  • Need drawings/design
  • Wiring locations
  • Purge lines
  • Close outs (specifically for odd locations (i.e. near apertures)
  • MLI Lay-ups
  • High temperature MLI lay-up
  • Embossed aluminized Kapton (10 layers)
  • Outer layer of StaMet on Black Kapton
  • Standard MLI lay-up
  • Mylar-dacron alternating layers (17 layers)
  • Outer layer of StaMet on Black Kapton
  • Thermal RequirementsInternal boxes and Contamination
  • Internal boxes (SWEM)
  • Surface finish shall have an IR emittance >0.85
  • Flatness requirement of 0.025 cm
  • Boxes will have thermally conductive mounting interface (CV-2946, TBR)
  • Internal boxes shall NOT have MLI
  • Contamination
  • Bakeouts will be performed of subsystems and components in order to ensure low spacecraft outgassing.  Bakeout candidates among others would include among; solar arrays, flight harness, MLI, boxes. (Bake-out requirements for high temperature components are TBD)
  • Thermal Resources
  • Mass
  • All thermal mass associated with the instruments is carried in the instrument MEL, including S/C controlled thermal hardware such as survival heaters
  • Instrument MELs should include brackets, MLI, heaters, harness, temperature sensors, etc.
  • S/C carries the mass up to interface for heaters & sensors
  • Temperature sensors
  • Each S/C mounted instrument will be allocated survival S/C controlled survival temperature sensors
  • Additional sensors required by the instrument are instrument responsibility
  • Heater power
  • Operational heater power is the responsibility of the instrument & maintained in the instrument power budget
  • Survival heater power (table) is maintained in the S/C power budget
  • FIELDS allocation for survival heater power is 5.0 W
  • Thermal Hardware
  • Procurement
  • Thermal hardware procurement is the responsibility of each instrument provider unless otherwise agreed upon
  • Heaters
  • Heater procurement by S/C can be arranged assuming schematic & funds are provided
  • Temperature sensors (thermistors)
  • Temperature sensors in S/C allocation will be provided by APL
  • MLI
  • APL will provide blanket material to all instrument teams
  • Ground straps
  • APL will provide ground straps for instruments & blankets
  • Related Search
    We Need Your Support
    Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

    Thanks to everyone for your continued support.

    No, Thanks