GOSAT MISSION and SPACECRAFT PARTS REQUIRMENTS

Transcription

1 MISSION and SPACECRAFT PARTS REQUIRMENTS OCT. 22, 2004 GOSAT PROJECT TEAM Japan Aerospace Exploration Agency (JAXA)

2 GOSAT Objectives (1) Kyoto Protocol (1997): Mandatory for Developed Nations to Reduce Green House Gases (GHG s) emission GOSAT ( ) collects data for Estimating the source and sink of GHGs at sub-continental scale GOSAT project is a joint project of JAXA, MOE* and NIES** *MOE: Ministry of Environment **NIES: National Institute for Environmental Studies 2

3 GOSAT Objectives(2) To contribute to the advancement of earth observation technologies for future missions. High reliability bus-system High speed data handling system Super Spectrometer (Over 20,000 channels) 3

4 Mission Targets(1) Observation of CO 2 density during the first commitment period (2008 to 2012) of the Kyoto Protocol Relative accuracy for 3-month average : 1% (4ppmv) at sub-continental 4

5 Mission Targets(2) Reduction of errors by half in identifying the GHGs source and sink at Subcontinental scale Data obtained by 1) GOSAT Sensor 2) Ground-based Instruments 5

6 Mission Sensor Main Sensor: Observing Sensor (GOS) Designed to detect Interferogram of 1) Solar Short Wave Infrared spectra (SWIR) reflected and scattered on the earth s surface 2) Solar Thermal Infrared spectra (TIR) radiated from the ground and the atmosphere. Earth Earth 1) SWIR Observation 2) TIR Observation 6

7 Mission Sensor Observing Sensor (GOS) a Michelson-type Fourier Transform Spectrometer (FTS) High optical throughput and spectral resolution M1: Fixed Mirror Light source Michelson-type FTS M2: Moving Mirror Detector Path-difference between path-a and path-b makes interferogram at the detector. A B 7

8 GOS Data Processing Flow M1: Fixed Mirror Light source FTS M2: Moving Mirror Detector Inverse FFT Interferogram Relative value H2O Wavenumber (cm-1) CO 2 and CH 4 absorption spectra CH4 CO2 Global distribution (CO 2 Column density) Source and sink in sub-continental scale 8

9 GOS Breadboard Model Baffle Light source Detector Swing Corner-cube mirror Path-difference between path-a and path-b makes interferogram at the detector. A B 9

10 Spacecraft (Main Specifications) Size Mass Power Life Span Orbit Launch Main body Total Total Altitude Inclination Re-visit Vehicle Schedule 1.5 x 2 x 3.2 m 1650kg ~ 3kW 5 years sun synchronous orbit 666km 98deg 3 days H-IIA Feb

11 Reliability improvement (1) Endurance and Survivability: Reduction of single failure points Additional redundancy systems Maximize data acquisition during contingency (2) Bus systems : Utilization of Flight-proven parts and components ( as many as possible ) (3) EEE parts: Utilization of Class I quality level and its equivalent parts (as many as possible ) 11

12 GOSAT PARTS (1) DEFINITIONS OF QUALIFIED PARTS CLASS Standard Parts Class ClassⅠ ClassⅡ Parts specification list JAXA QPL/QML parts NPSL level 1 parts GSFC EEE-INST-002 Level 1 parts GSFC PPL-21 Grade1 parts ESCC (or ESA/SCC) QPLlevel B parts EPPL partⅠparts MIL QPL/QML parts(npsl level 1 equivalent) JAXA QPL/QML JAXAClassII parts NPSL level 2 parts GSFC EEE-INST-002 Level 2 parts GSFC PPL-21 Grade 2 parts ESCC (or ESA/SCC) QPL level C parts EPPL partⅡparts MIL QPL/QML parts(npsl Level 2 equivalent) Nonstandard Parts Well established / recognized parts for satellite Non-established / recognized parts for satellite Flight proven parts or evaluated parts for satellites, and parts with established specs and qualification test data equivalent to standard parts Available to obtain technical data Parts need to be established new specs and new qualification test data and technical data equivalent to standard parts Available to get technical data 12

13 GOSAT PARTS (2) Case study a) Cost Estimation of Parts Case Model: Virtual Earth observation satellite (larger than GOSAT) Investigated parts: IC, Transistor, Diode IC: ~200typs,~1400 pcs, Tr.: ~20typs, ~4800pcs, Di.:~40typs, ~1200 pcs Comparison of total costs Class I : 100 % Class II + : 87 % Class II : 73 % Note: 1) Class I parts case: Using class II+ (: up-screening) parts when class I part purchases are not available. Class II+ and II parts case: Using class I parts when class II part purchases are not available 2) This cost are included data packages, DPA, and RVT(if necessary) 13

14 GOSAT PARTS b) Comparison average unit prices between part s quality level Transistor Total parts number: IC Total parts number: 119 Ratio Class I Class II+ Class II Ratio Class I Class II+ Class II <= < <= < <= < <= < Class I unit price ($) Diod Total parts number: <= < <= < <= < <=10000 Class I unit price ($) 10000< <= < Ratio Class I Class II+ Class II <= < <= < <= < <= < <= < Class I unit price ($) 14

15 GOSAT PARTS (3) Parts Selection Requirement Subsystems for All flight parts (except subsystems described right) for TEDA (except interface parts) Standard Parts Nonstandard Parts ClassⅠ standard ClassⅡ standard parts Well established / recognized parts for satellite Nonestablished / recognized parts for satellite as is 1)Up screening requirement: ClassⅠstandard part equivalent 2)NSPAR approval: necessary condition 3)Preparation documents for NSPAR: 1non-standard part approval request application, 2Part spec, 3Test data, 4Explanation of difference between ClassⅠstandard part 1)Up screening requirement: ClassⅠstandard part equivalent 2)NSPAR approval: necessary condition 3)Preparation documents for NSPAR: 1non-standard part approval request application, 2Part spec, 3Test data, 4Explanation of structure 5Used satellite names & subsystems 1)Up screening requirement: ClassⅠstandard part equivalent 2)NSPAR approval: necessary condition 3)Preparation documents for NSPAR: 1non-standard part approval request application, 2Part spec, 3Test data, 4Explanation of structure 5Estimation of reliability for GOSAT parts NSPAR: Non-Standard Part Approval Request as is as is Confirmed upon negotiation with JAXA Confirmed upon negotiation with JAXA changed 15

16 Appendix: Up-screening conditions for case study 1) For IC L/I Screen MIL-STD-883 test method Note 1 PIND 2020, test condition A 2 Serialization (1) Marking shall be passed per method 2015 of MIL-STD-883 and marking material shall be met for the following outgassing characteristics per ASTM E TML: 1.0% or less - CVCM: 0.1% or less (2) All numerical characters shall be "type"(not hand written). (3) Serial number may be identified under tag when there cannot be marked on the surface of the part. 3 Radiographic 2012, two views 4 Pre burn-in electrical test Measured at room temperature only. 5 Burn-in (Dynamic) 1015, 160 hours at 125 degree C minimum 6 Post burn-in electrical test Measured at room temperature only. 7 Delta calculation 8 PDA calculation 5% 9 Final electrical test Measured at high and low temperatures. 10 Seal (Fine & Gross) External visual ) For Tr & Di MIL-STD-750 Screen Note test method 1 PIND 2052, condition A 2 Serialization (1) Marking shall be passed per method 2015 of MIL-STD-883 and marking material shall be met for the following outgassing characteristics per ASTM E TML: 1.0% or less - CVCM: 0.1% or less (2) All numerical characters shall be "type"(not hand written). (3) Serial number may be identified under tag when there cannot be marked on the surface of the part. 3 Radiography Interim electrical and delta L/I parameters for PDA 5 Burn-in For bipolar transistors 1039, test condition B, 160 hours minimum For powerfets 1042, test condition A, 160 hours minimum For diodes, zeners and rectifiers 6 Final electrical test 7 Delta calculation 8 PDA calculation 10% 9 Hermetic seal (Fine and Gross) External visual , test condition B, 160 hours minimum