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SPICA / AIV&T issues
Spacecraft 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


No deployable mechanism


Simple, Feasible, Reliable
Smooth PSF


Ceramic material (SiC)
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)
STA Optical 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
4
STA Optical Performance test
at cold (2)
2
LN2 Shroud
GHe Shroud
Flat-mirror
STA
ACF
Cryo
Sorption
Pumps
5
Interfero
meter
6
ACF
8
1
7
Gear
Motor
Turbo
Molecular
Pumps
5-axis
stage
Test Specimen Mount Table (with Shroud)
4
Anti-Vibration Table
GHe
3
Pillar of Vacuum Vessel
LN2
Independent Foundation
5
PLM Thermal Test at cold

Purpose


Date & Duration



Evaluation of PLM cooling
system performances
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
6
SPICA AIV&T timeline
(tentative)
7
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)


(c) Co-operation with FPC-G to establish the
pointing stability


To assure high-sensitivity (low-noise) in orbit
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


Required Function





Mechanical I/F specifications (including disturbance
sources) is equivalent to that of FM
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


Required Function




Nearly equivalent to FM incorporating with detectors
operable at low-temperature expected in orbit
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:




With CQM:




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
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
12
Focal Plane Instrument
Assembly (FPIA) = IOB+FPI
2300
TOB：Telescope
Optical Bench
IOB: Instrument
Optical Bench
13
FPI Evaluation at cold (1)

Date & Duration:


Place：


6m Space Chamber at Tsukuba Space Centre (tbd)
Configuration:


latter half of CY2016, 1-2 months
IOB(FM dummy)＋FPI(FM)＋cooler(TBD)＋FPI warm
electronics (FM) (＋STA Simulator..)
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.
14
FPI Evaluation at cold (2)
IOB
FPI
FPI
LHe
Mech. cooler
15