Download
1 / 15
150 likes | 273 Views
This document outlines the AIV&T (Assembly, Integration, Verification & Testing) issues related to the SPICA spacecraft program, focusing on the development of its Telescope Assembly (STA). It details the mechanical design, thermal models, and optical performance testing strategies that are critical for achieving the mission’s goals. The plan includes timelines for model deliveries, environmental testing, and performance evaluations, with particular attention to the needs of the Focal Plane Instrument (FPI) and its operational integrity in orbit.
E N D
SPICA / AIV&T issuesSpacecraft test program & model philosophy (tentative plan) Feb. 19 2010 revised Nov. 19, 2009 1st draft by H. Matsuhara, N. Takahashi, T. Nakagawa
ＳＰＩＣＡ Telescope Assembly (STA) • 3m-class cooled telescope • Monolithic Mirror • Ceramic material (SiC) • No deployable mechanism • Simple, Feasible, Reliable • Smooth PSF • Essential for Coronagraph • Herschel & AKARI Heritage • SPICA: WFE 0.35μm, 5K (3.5m) • AKARI: WFE 0.35μm, 6K (70cm) • Herschel: WFE 6μm, 80K (3.5m)
STA models & proposed delivery (tentative plan) • STM (Structure Thermal Model) • Proposed delivery : Oct. 2012 (beginning of 3Q of FY2012) • AIT plan • Integrated as PLM (STM) • Thermal test at cold (@Tsukuba 13m chamber) • Integrated into Spacecraft (STM) • Spacecraft Mechanical Environmental test & Thermal Vacuum Test • FM • Proposed delivery : Jan. 2017 (beginning of 4Q 2016)
STAOptical Performance test at cold (1) • Date & duration： • 1Q of CY2017, 1-2 months • Place : • 6m Space Chamber in Tsukuba Space Center • Configuration • IOB（ＦＭ）＋STA(FM) • Additional thermal sheild in the chamber • Purposes: • Optical performance evaluation of ＳＴＡ at <10K • Multiple measurements are connected by the Stitching Method
STAOptical Performance test at cold (2) Flat-mirror STA 5-axis stage
PLM Thermal Test at cold • Purpose • Evaluation of PLM cooling system performances • Date & Duration • STM: April 2013 • FM: Dec. 2017, ~2months • Method • Additional shields in the existing 13m space chamber in Tsukuba • Shields are externally lifted by mechanical coolers
Key issues for FPI AIV&T • FPI’s system-level test plan should take account of the critical issues as below: • (a) FPI is cooled to <5K with J-T coolers under extremely careful Spacecraft thermal design. • (b) disturbance and interference from J-T coolers and AOCS (such as RW, gyro) • To assure high-sensitivity (low-noise) in orbit • (c) Co-operation with FPC-G to establish the pointing stability • Interferences? Alignment? • (d) Co-focus among FPIs (especially MIR’s) • Since STA 2ry cannot be adjusted so frequently in orbit
FPI Model philosophy • Cold FPIs • Minimum number of Models required for the system level test (in the previous page) is: • FM (Flight Model) (& its spare) • STM : structure thermal model • CQM : cold qualification model • Delivery date of FM: • June 2016 (August 2016 at worst) in the proposed scenario. • Warm Electronics • Similar as above, except for the terminology (CQM PM (proto-model) • Spacecraft DHS simulator(SpaceWire I/F) will be developed, and distributed hopefully before 2014 ( under discussion)
STM (Structure Thermal Model) for FPIs • Description • Mechanical I/F specifications (including disturbance sources) is equivalent to that of FM • Required Function • Same mechanical I/F specifications to FM • Nearly the same thermal I/F (TBD, for spacecraft(PM) thermal test) • Equipped with thermometers, acceleration sensors for measurement of I/F environmental condition • Simulate mechanical disturbance according to the system operation modes • Proposed Delivery • Oct. 2012 : before starting of assembly of PLM(STM) for the system Mechanical & Thermal Test
CQM (Cold Qualification Model) for FPIs • Description • Nearly equivalent to FM incorporating with detectors operable at low-temperature expected in orbit • Required Function • Same thermal, mechanical, electrical I/F specifications to FM • Equipped with detectors operable at low-temperature, with the same noise performance as that of FM • Simulate heat-dissipation (load to J-Ts), mechanical disturbance according to the system operation modes • Proposed Delivery • Apr. 2015 : when the PLM(FM) is available for us to test the items (a), (b), & (c) in page 8.
FPI: ＳＰＩＣＡ system test plan • With STM: • Mechanical Environmental test & thermal test at cold at the PLM level • Mechanical Environmental test & Thermal vacuum test at Spacecraft level • Measure disturbance at FPI from J-T cooler/AOCS • With CQM: • Cooling compliance test with J-T (PM) • Evaluate effect of mechanical disturbances from J-T (PM) and AOCS simulator, • Evaluate electrical interferences among FPIs, J-T, AOCS in the latter half of FY2015 • With FM • FPI evaluation at cold (optical & electrical) • STA optical performance test at cold • Thermal test at cold at PLM level
Focal Plane Instrument Assembly (FPIA) = IOB+FPI TOB：Telescope Optical Bench IOB: Instrument Optical Bench 2300
FPI Evaluation at cold (1) • Date & Duration: • latter half of CY2016, 1-2 months • Place： • 6m Space Chamber at Tsukuba Space Centre (tbd) • Configuration: • IOB(FM dummy)＋FPI(FM)＋cooler(TBD)＋FPI warm electronics (FM) (＋STASimulator..) • Purposes: • With all FM FPIs together, all functional, electrical & optical performance evaluation at cold (operating temperature in orbit) as well as interference test. • Optical performance will be measures with a STA simulator.
FPI Evaluation at cold (2) IOB FPI FPI LHe Mech. cooler
