July 19, 2005

TO: Lillian Reichenthal

> STEREO Instrument Manager

FROM: 545/Thermal Engineering/J. Hawk

SUBJECT: SIT/SEPT -- Thermal Vacuum and Thermal Balance Test Report

This report is to provide the results of the Suprathermal Ion Telecope
(SIT), and the Solar Electron Proton Telescope (SEPT) thermal balance
(TB) tests. Also included in this report are the results of the SIT
instruments thermal vacuum (TV) tests. The tests were conducted in the
Dynavac thermal vacuum chamber, building 7 at the NASA GSFC.

These Instrument level tests were conducted to fulfill the thermal
vacuum requirement for the SEPT and SIT instruments. The tests consisted
of two thermal balance phases with a chamber break in between.
Subsequently, the SIT instruments underwent thermal vacuum cycling. SEPT
had already completed the required instrument level TV cycling. The
Phase 1 thermal balance test was conducted from February 10 through
February 17, 2005 and included test articles SEPT-E Ahead, SEPT-E Behind
and SIT Ahead. The Phase 2 thermal balance test was conducted from
February 21 through March 9, 2005 and included test articles SEPT-NS
Ahead, SEPT-NS Behind and SIT Behind. Next, the AHEAD and BEHIND SIT
instruments underwent thermal vacuum cycling. Shown in Figures 1 and 2
is the Phase 1 thermal balance test set-up. Figures 4 and 5 show the
Phase 2 thermal balance test set-up. The SIT thermal vacuum test set-up
is shown in Figure 6. During the SIT Ahead TB the instrument
temperatures were significantly warmer than predicted (\~20°C). After
the Phase 1 TB chamber break, it was discovered that the thin film
thermal coating for the radiators were applied with the low emissivity
inconel side facing out instead of the high emissivity ITO silver Teflon
side. Inconel's low emissivity explained the significantly warmer than
predicted temperatures. The thermal coating was removed and replaced
correctly with the ITO silver Teflon side facing out and TB was repeated
on SIT Ahead.

**[Thermal Balance Results]{.underline}**

Data from the TB test was used to correlate the thermal model. After
minor changes to the thermal model thermal blanket effectiveness and
isolator conductance couplings the temperature predictions matched test
results within an average of 2ºC.

Flight predictions were made with the correlated model for the three
cases:

-   Cold Survival

-   Cold Operational

-   Hot Operational

The test setup was carried out according to the STEREO-GSFC-002.C test
plan. The assemblies were mounted to the interface plate using the
flight isolator feet. Flight-like MLI was installed in the flight
configuration. The radiator surfaces have the flight high emissivity ITO
silver Teflon installed to dissipate heat. Ground straps between the
test article and the interface plate were configured as flight-like as
possible. Flight cables were routed and secured to the interface plate
as flight-like as possible. The cables, which in flight run along the
spacecraft deck, were coiled up and attached to the interface plate
under the MLI blanket. GSE cables ran from the flight cables to the
chamber feed-thru connecter and to external GSE.

![](media/image1.png){width="5.084027777777778in"
height="5.780555555555556in"}

Figure 1 SIT/SEPT Phase 1 TB Test Set-up

![](media/image2.png){width="5.982638888888889in"
height="4.518055555555556in"} Figure 2 SIT/SEPT Phase 1 TB Test

![](media/image3.png){width="5.010416666666667in"
height="5.114583333333333in"}

Figure 3 SIT AHEAD TB Retest Set-up

![](media/image4.png){width="4.722916666666666in"
height="5.223611111111111in"}

Figure 4 SIT/SEPT Phase 2 TB Test Set-up

![](media/image5.png){width="5.99375in" height="4.495138888888889in"}

Figure 5 SIT/SEPT Phase 2 TB Test

**TABLE 1: Phase 1 Comparison Test vs. Analysis Results (°C)**

  ------------- --------------------------- ---------- ----------- ---------- ---------
  **Survival                                                                  
  Cases**                                                                     

  SEPT AHEAD                                                                  
  Ecliptic                                                                    

   TC \#        Location                    Measured   NODE \#     Predicts   DELTA T

  TC24          Front of SEPTA on Bracket   -12.9      ASEPT.93    -14.0      1.1
                Ecliptic                                                      

  TC25          Front of SEPTA Telescope    -13.0      ASEPT.64    -14.5      1.6
                Ecliptic                                                      

  TC26          Front of SEPTA Telescope    -12.2      ASEPT.21    -15.3      3.1
                Ecliptic                                                      

  TC27          Front of SEPTA Telescope    -12.3      ASEPT.21    -15.3      3.0
                Ecliptic                                                      

  TC28          Front of SEPTA on Bracket   -12.3      ASEPT.106   -14.7      2.5
                Ecliptic                                                      

  TC29          Front of SEPTA on Bracket   -13.0      ASEPT.94    -14.1      1.1
                Ecliptic                                                      

  TC30          Front of SEPTA EBOX         -12.6      ASEPT.35    -14.6      2.0
                Ecliptic                                                      

  TC31          Back of SEPTA on Bracket    -13.1      ASEPT.105   -14.6      1.5
                Ecliptic                                                      

  TC32          Back of SEPTA Telescope     -13.2      ASEPT.82    -14.0      0.8
                Ecliptic                                                      

  TC33          Back of SEPTA Telescope     -13.7      ASEPT.28    -13.0      0.6
                Ecliptic                                                      

  TC34          Back of SEPTA Telescope     -13.9      ASEPT.28    -13.0      0.8
                Ecliptic                                                      

  TC35          Back of SEPTA on Bracket    -13.8      ASEPT.92    -13.9      0.1
                Ecliptic                                                      

  TC36          Back of SEPTA on Bracket    -12.6      ASEPT.109   -14.6      2.1
                Ecliptic                                                      

  TC37          Back of SEPTA EBOX Ecliptic -12.6      ASEPT.40    -14.6      1.9

  TC38          Bottom of SEPTA Bracket     -12.0      ASEPT.109   -14.6      2.7
                Ecliptic                                                      

  TC39          Bottom of SEPTA Bracket     -12.8      ASEPT.94    -14.1      1.4
                Ecliptic                                                      

  TC40          Radiator Side of SEPTA      -13.6      ASEPT.39    -14.4      0.8
                Ecliptic                                                      

  TC106         Bottom of SEPTA Ecliptic    -13.5      ASEPT.36    -14.4      0.9

  TC107         Bottom of SEPTA Ecliptic    -12.4      ASEPT.36    -14.4      2.0

  SEPT BEHIND                                                                 
  Ecliptic                                                                    

                                            Measured   NODE        Predicts   DELTA T

  TC108         Front of SEPTB on Bracket   -27.8      BSEPT.93    -27.2      0.6

  TC109         Front of SEPTB Telescope    -27.6      BSEPT.64    -26.7      0.9

  TC110         Front of SEPTB Telescope    -27.7      BSEPT.21    -26.4      1.3

  TC111         Front of SEPTB Telescope    -27.6      BSEPT.21    -26.4      1.2

  TC112         Front of SEPTB on Bracket   -27.1      BSEPT.106   -27.2      0.1

  TC113         Front of SEPTB on Bracket   -27.9      BSEPT.94    -27.3      0.6

  TC114         Front of SEPTB EBOX         -27.2      BSEPT.35    -27.4      0.3

  TC115         Back of SEPTB on Bracket    -27.1      BSEPT.105   -27.3      0.2

  TC116         Back of SEPTB Telescope     -27.2      BSEPT.82    -27.5      0.3

  TC117         Back of SEPTB Telescope     -27.2      BSEPT.28    -27.6      0.4

  TC118         Back of SEPTB Telescope     -27.3      BSEPT.28    -27.6      0.3

  TC119         Back of SEPTB on Bracket    -27.7      BSEPT.92    -27.2      0.5

  TC120         Back of SEPTB on Bracket    -26.9      BSEPT.109   -27.3      0.5

  TC121         Back of SEPTB EBOX          -27.4      BSEPT.40    -27.5      0.1

  TC122         Bottom of SEPTB Bracket     -26.9      BSEPT.109   -27.3      0.5

  TC123         Bottom of SEPTB Bracket     -28.3      BSEPT.94    -27.3      1.0

  TC126         Radiator Side of SEPTB EBOX -28.8      BSEPT.39    -27.3      1.5

  TC124         Bottom of SEPTB             -27.5      BSEPT.36    -27.1      0.4

  TC125         Bottom of SEPTB             -26.7      BSEPT.36    -27.1      0.4

  **Cold                                                                      
  Operational                                                                 
  Cases**                                                                     

  SEPT AHEAD                                                                  
  Ecliptic                                                                    

  TC \#         Location                    Measured   NODE \#     Predicts   DELTA T

  TC24          Front of SEPTA on Bracket   -6.2       ASEPT.93    -9.1       2.9
                Ecliptic                                                      

  TC25          Front of SEPTA Telescope    -6.2       ASEPT.64    -9.8       3.6
                Ecliptic                                                      

  TC26          Front of SEPTA Telescope    -5.5       ASEPT.21    -10.7      5.2
                Ecliptic                                                      

  TC27          Front of SEPTA Telescope    -5.6       ASEPT.21    -10.7      5.1
                Ecliptic                                                      

  TC28          Front of SEPTA on Bracket   -5.4       ASEPT.106   -9.8       4.4
                Ecliptic                                                      

  TC29          Front of SEPTA on Bracket   -6.3       ASEPT.94    -9.0       2.7
                Ecliptic                                                      

  TC30          Front of SEPTA EBOX         -5.4       ASEPT.35    -8.8       3.4
                Ecliptic                                                      

  TC31          Back of SEPTA on Bracket    -6.3       ASEPT.105   -9.7       3.4
                Ecliptic                                                      

  TC32          Back of SEPTA Telescope     -6.5       ASEPT.82    -9.2       2.7
                Ecliptic                                                      

  TC33          Back of SEPTA Telescope     -7.0       ASEPT.28    -8.4       1.4
                Ecliptic                                                      

  TC34          Back of SEPTA Telescope     -7.2       ASEPT.28    -8.4       1.2
                Ecliptic                                                      

  TC35          Back of SEPTA on Bracket    -7.1       ASEPT.92    -8.9       1.9
                Ecliptic                                                      

  TC36          Back of SEPTA on Bracket    -5.6       ASEPT.109   -9.6       3.9
                Ecliptic                                                      

  TC37          Back of SEPTA EBOX Ecliptic -5.5       ASEPT.40    -8.8       3.3

  TC38          Bottom of SEPTA Bracket     -5.1       ASEPT.109   -9.6       4.5
                Ecliptic                                                      

  TC39          Bottom of SEPTA Bracket     -6.0       ASEPT.94    -9.0       3.0
                Ecliptic                                                      

  TC40          Radiator Side of SEPTA      -6.9       ASEPT.39    -8.9       2.0
                Ecliptic                                                      

  TC106         Bottom of SEPTA Ecliptic    -7.0       ASEPT.36    -9.1       2.1

  TC107         Bottom of SEPTA Ecliptic    -5.6       ASEPT.36    -9.1       3.5

  SEPT BEHIND                                                                 
  Ecliptic                                                                    

  TC108         Front of SEPTB on Bracket   -20.2      BSEPT.93    -18.0      2.2

  TC109         Front of SEPTB Telescope    -20.0      BSEPT.64    -17.7      2.3

  TC110         Front of SEPTB Telescope    -20.1      BSEPT.21    -17.7      2.4

  TC111         Front of SEPTB Telescope    -19.9      BSEPT.21    -17.7      2.2

  TC112         Front of SEPTB on Bracket   -19.3      BSEPT.106   -18.1      1.2

  TC113         Front of SEPTB on Bracket   -20.2      BSEPT.94    -18.0      2.2

  TC114         Front of SEPTB EBOX         -19.1      BSEPT.35    -17.5      1.6

  TC115         Back of SEPTB on Bracket    -19.3      BSEPT.105   -18.2      1.2

  TC116         Back of SEPTB Telescope     -19.5      BSEPT.82    -18.6      0.9

  TC117         Back of SEPTB Telescope     -19.6      BSEPT.28    -18.9      0.7

  TC118         Back of SEPTB Telescope     -19.7      BSEPT.28    -18.9      0.8

  TC119         Back of SEPTB on Bracket    -20.0      BSEPT.92    -18.1      1.9

  TC120         Back of SEPTB on Bracket    -19.0      BSEPT.109   -18.1      1.0

  TC121         Back of SEPTB EBOX          -19.3      BSEPT.40    -17.5      1.8

  TC122         Bottom of SEPTB Bracket     -18.9      BSEPT.109   -18.1      0.8

  TC123         Bottom of SEPTB Bracket     -20.5      BSEPT.94    -18.0      2.5

  TC126         Radiator Side of SEPTB EBOX -21.1      BSEPT.39    -17.6      3.5

  TC124         Bottom of SEPTB             -19.9      BSEPT.36    -17.7      2.3

  TC125         Bottom of SEPTB             -18.8      BSEPT.36    -17.7      1.1

  **Hot                                                                       
  Operational                                                                 
  Cases**                                                                     

  SEPT AHEAD                                                                  
  Ecliptic                                                                    

                                            Measured   NODE \#     Predicts   DELTA T

  TC24          Front of SEPTA on Bracket   24.0       ASEPT.93    20.8       3.2
                Ecliptic                                                      

  TC25          Front of SEPTA Telescope    24.1       ASEPT.64    19.9       4.2
                Ecliptic                                                      

  TC26          Front of SEPTA Telescope    25.1       ASEPT.21    18.6       6.5
                Ecliptic                                                      

  TC27          Front of SEPTA Telescope    25.2       ASEPT.21    18.6       6.6
                Ecliptic                                                      

  TC28          Front of SEPTA on Bracket   25.1       ASEPT.106   19.6       5.5
                Ecliptic                                                      

  TC29          Front of SEPTA on Bracket   23.7       ASEPT.94    20.6       3.1
                Ecliptic                                                      

  TC30          Front of SEPTA EBOX         24.6       ASEPT.35    20.0       4.6
                Ecliptic                                                      

  TC31          Back of SEPTA on Bracket    23.9       ASEPT.105   19.8       4.1
                Ecliptic                                                      

  TC32          Back of SEPTA Telescope     23.6       ASEPT.82    20.9       2.8
                Ecliptic                                                      

  TC33          Back of SEPTA Telescope     22.9       ASEPT.28    22.4       0.5
                Ecliptic                                                      

  TC34          Back of SEPTA Telescope     22.6       ASEPT.28    22.4       0.2
                Ecliptic                                                      

  TC35          Back of SEPTA on Bracket    22.7       ASEPT.92    21.0       1.7
                Ecliptic                                                      

  TC36          Back of SEPTA on Bracket    24.5       ASEPT.109   19.7       4.8
                Ecliptic                                                      

  TC37          Back of SEPTA EBOX Ecliptic 24.3       ASEPT.40    20.0       4.3

  TC38          Bottom of SEPTA Bracket     25.1       ASEPT.109   19.7       5.3
                Ecliptic                                                      

  TC39          Bottom of SEPTA Bracket     23.9       ASEPT.94    20.6       3.3
                Ecliptic                                                      

  TC40          Radiator Side of SEPTA      22.5       ASEPT.39    20.0       2.4
                Ecliptic                                                      

  TC106         Bottom of SEPTA Ecliptic    22.7       ASEPT.36    19.6       3.1

  TC107         Bottom of SEPTA Ecliptic    24.6       ASEPT.36    19.6       5.0

  SEPT BEHIND                                                                 
  Ecliptic                                                                    

                                            Measured   NODE \#     Predicts   DELTA T

  TC108         Front of SEPTB on Bracket   2.0        BSEPT.93    5.8        3.8

  TC109         Front of SEPTB Telescope    2.1        BSEPT.64    6.6        4.5

  TC110         Front of SEPTB Telescope    2.1        BSEPT.21    6.9        4.8

  TC111         Front of SEPTB Telescope    2.3        BSEPT.21    6.9        4.6

  TC112         Front of SEPTB on Bracket   3.0        BSEPT.106   5.7        2.8

  TC113         Front of SEPTB on Bracket   1.6        BSEPT.94    5.6        4.0

  TC114         Front of SEPTB EBOX         2.8        BSEPT.35    5.4        2.6

  TC115         Back of SEPTB on Bracket    3.0        BSEPT.105   5.6        2.6

  TC116         Back of SEPTB Telescope     2.9        BSEPT.82    5.2        2.3

  TC117         Back of SEPTB Telescope     2.9        BSEPT.28    5.0        2.1

  TC118         Back of SEPTB Telescope     2.8        BSEPT.28    5.0        2.3

  TC119         Back of SEPTB on Bracket    2.1        BSEPT.92    5.7        3.6

  TC120         Back of SEPTB on Bracket    3.4        BSEPT.109   5.5        2.0

  TC121         Back of SEPTB EBOX          2.7        BSEPT.40    5.4        2.7

  TC122         Bottom of SEPTB Bracket     3.5        BSEPT.109   5.5        2.0

  TC123         Bottom of SEPTB Bracket     1.3        BSEPT.94    5.6        4.3

  TC126         Radiator Side of SEPTB EBOX 0.2        BSEPT.39    5.4        5.2

  TC124         Bottom of SEPTB             1.8        BSEPT.36    5.2        3.5

  TC125         Bottom of SEPTB             3.4        BSEPT.36    5.2        1.8
  ------------- --------------------------- ---------- ----------- ---------- ---------

**TABLE 2: Phase 2** Comparison Test vs. Analysis Results (°C)

  ------------- ------------------------------- ---------- ------------- ---------- --------
  **Survival                                                                        
  Cases**                                                                           

  SIT BEHIND                                                                        

  TC #          Location                        Measured   NODE \#       Predicts   DELTA T

  TC1           Front of SIT EBOX Behind        -29.8      BSIT.444      -27.0      2.9

  TC2           Front of HVPS Behind            -30.0      BPOWER.325    -27.1      2.9

  TC3           Right Side of SIT EBOX Behind   NA         BSIT.431      -27.0      NA

  TC4           Right Side of HVPS Behind       -30.1      BPOWER.328    -27.1      3.0

  TC5           Right Side of SIT Telescope     -30.7      BSIT.435      -27.9      2.7
                Behind                                                              

  TC6           Top of SIT Telescope Behind     -30.0      BSIT.433      -28.3      1.8

  TC7           Top Front of SIT Telescope      -31.8      BSIT.425      -29.2      2.6
                Behind                                                              

  TC8           Top of SIT Collimator Behind    -51.2      BSIT.437      -45.3      5.9

  TC9           Right Side of SIT Collimator    -49.5      BSIT.419      -45.0      4.5
                Behind                                                              

  TC10          Front of SIT Telescope Behind   -31.4      BSIT.429      -28.4      3.0

  TC11          Top of SIT Telescope Behind     -30.5      BSIT.433      -28.3      2.3

  TC12          Back of SIT Telescope Behind    -30.5      BSIT.415      -27.8      2.7

  TC13          Left Side of SIT Ebox Behind    -29.4      BSIT.431      -27.0      2.4

  TC14          Left Side of HVPS Behind        -29.8      BPOWER.327    -27.1      2.7

  TC15          Left Side of SIT Telescope      -31.5      BSIT.413      -28.0      3.6
                Behind                                                              

  TC16          Front of SIT Telescope Behind   -32.1      BSIT.429      -28.4      3.6

  TC17          Back of SIT Telescope Behind    -30.8      BSIT.415      -27.8      3.1

  TC18          Back of HVPS Behind             -30.1      BPOWER.326    -27.1      2.9

  TC19          Back of SIT EBOX Behind         -29.5      BSIT.409      -27.0      2.6

  TC20          Bottom of SIT EBOX Behind       -29.5      BSIT.432      -26.9      2.6

  TC21          Bottom of SIT EBOX Behind       -29.6      BSIT.432      -26.9      2.7

  TC22          Under SIT Collimator exterior   -51.5      BSIT.427      -45.2      6.3
                Behind                                                              

  TC23          Right Side of SIT Collimator    -50.6      BSIT.419      -45.0      5.5
                Behind                                                              

  SEPT AHEAD NS                                                                     

  TC #          Location                        Measured   NODE          Predicts   DELTA T

  TC24          Front of SEPTA on Bracket NS    -20.0      SEPTNS.93     -20.8      0.9

  TC25          Front of SEPTA Telescope NS     -20.1      SEPTNS.64     -21.1      1.0

  TC26          Front of SEPTA Telescope NS     -20.3      SEPTNS.21     -22.0      1.7

  TC27          Front of SEPTA Telescope NS     -20.3      SEPTNS.21     -22.0      1.7

  TC28          Front of SEPTA on Bracket NS    -19.1      SEPTNS.106    -21.0      1.9

  TC29          Front of SEPTA on Bracket NS    -19.3      SEPTNS.94     -19.3      0.0

  TC30          Front of SEPTA EBOX NS          -16.6      SEPTNS.35     -15.2      1.4

  TC31          Back of SEPTA on Bracket NS     -19.7      SEPTNS.105    -20.9      1.2

  TC32          Back of SEPTA Telescope NS      -19.7      SEPTNS.82     -21.1      1.4

  TC33          Back of SEPTA Telescope NS      -20.7      SEPTNS.28     -21.9      1.3

  TC34          Back of SEPTA Telescope NS      -20.7      SEPTNS.28     -21.9      1.2

  TC35          Back of SEPTA on Bracket NS     -19.8      SEPTNS.92     -21.0      1.1

  TC36          Back of SEPTA on Bracket NS     -18.5      SEPTNS.109    -19.3      0.8

  TC37          Back of SEPTA EBOX NS           -16.4      SEPTNS.40     -15.2      1.2

  TC38          Bottom of SEPTA Bracket NS      -16.9      SEPTNS.109    -19.3      2.4

  TC39          Bottom of SEPTA Bracket NS      -18.0      SEPTNS.94     -19.3      1.3

  TC40          Radiator Side of SEPTA NS       -16.9      SEPTNS.39     -15.2      1.7

  TC106         Bottom of SEPTA NS              -16.0      SEPTNS.36     -13.5      2.5

  TC107         Bottom of SEPTA NS              -14.6      SEPTNS.36     -13.5      1.1

  SEPT BEHIND                                                                       
  NS                                                                                

  TC #          Location                        Measured   NODE          Predicts   DELTA T

  TC108         Front of SEPTB on Bracket NS    -16.6      SEPTNSB.93    -21.1      4.5

  TC109         Front of SEPTB Telescope NS     -17.0      SEPTNSB.64    -21.4      4.4

  TC110         Front of SEPTB Telescope NS     -17.1      SEPTNSB.21    -22.2      5.1

  TC111         Front of SEPTB Telescope NS     -16.9      SEPTNSB.21    -22.2      5.3

  TC112         Front of SEPTB on Bracket NS    -15.9      SEPTNSB.106   -21.2      5.3

  TC113         Front of SEPTB on Bracket NS    -15.1      SEPTNSB.94    -19.6      4.5

  TC114         Front of SEPTB EBOX NS          -12.9      SEPTNSB.35    -15.4      2.5

  TC115         Back of SEPTB on Bracket NS     -16.2      SEPTNSB.105   -21.1      4.9

  TC116         Back of SEPTB Telescope NS      -16.7      SEPTNSB.82    -21.4      4.7

  TC117         Back of SEPTB Telescope NS      -17.7      SEPTNSB.28    -22.3      4.6

  TC118         Back of SEPTB Telescope NS      -17.8      SEPTNSB.28    -22.3      4.4

  TC119         Back of SEPTB on Bracket NS     -16.1      SEPTNSB.92    -21.3      5.1

  TC120         Back of SEPTB on Bracket NS     -17.1      SEPTNSB.109   -19.6      2.4

  TC121         Back of SEPTB EBOX NS           -14.0      SEPTNSB.40    -15.4      1.5

  TC122         Bottom of SEPTB Bracket NS      -15.4      SEPTNSB.109   -19.6      4.2

  TC123         Bottom of SEPTB Bracket NS      -15.2      SEPTNSB.94    -19.6      4.4

  TC126         Radiator Side of SEPTB EBOX NS  -13.7      SEPTNSB.39    -15.4      1.7

  TC124         Bottom of SEPTB NS              -10.6      SEPTNSB.36    -13.8      3.2

  TC125         Bottom of SEPTB NS              NA         SEPTNSB.36    -13.8      NA

  **Cold                                                                            
  Operational                                                                       
  Cases**                                                                           

  SIT BEHIND                                                                        

  TC #          Location                        Measured   NODE \#       Predicts   DELTA T

  TC1           Front of SIT EBOX Behind        0.7        BSIT.444      -1.7       2.4

  TC2           Front of HVPS Behind            0.3        BPOWER.325    -1.7       1.9

  TC3           Right Side of SIT EBOX Behind   NA         BSIT.431      -1.6       NA

  TC4           Right Side of HVPS Behind       0.1        BPOWER.328    -1.6       1.7

  TC5           Right Side of SIT Telescope     -9.6       BSIT.435      -10.2      0.6
                Behind                                                              

  TC6           Top of SIT Telescope Behind     -9.7       BSIT.433      -10.6      0.9

  TC7           Top Front of SIT Telescope      -11.0      BSIT.425      -11.8      0.8
                Behind                                                              

  TC8           Top of SIT Collimator Behind    -33.9      BSIT.437      -32.3      1.7

  TC9           Right Side of SIT Collimator    -32.0      BSIT.419      -31.9      0.1
                Behind                                                              

  TC10          Front of SIT Telescope Behind   -10.2      BSIT.429      -10.8      0.6

  TC11          Top of SIT Telescope Behind     -9.1       BSIT.433      -10.6      1.5

  TC12          Back of SIT Telescope Behind    -8.5       BSIT.415      -10.0      1.5

  TC13          Left Side of SIT Ebox Behind    0.9        BSIT.431      -1.6       2.5

  TC14          Left Side of HVPS Behind        0.5        BPOWER.327    -1.7       2.2

  TC15          Left Side of SIT Telescope      -8.4       BSIT.413      -10.2      1.9
                Behind                                                              

  TC16          Front of SIT Telescope Behind   -9.2       BSIT.429      -10.8      1.6

  TC17          Back of SIT Telescope Behind    -8.5       BSIT.415      -10.0      1.5

  TC18          Back of HVPS Behind             0.1        BPOWER.326    -1.7       1.7

  TC19          Back of SIT EBOX Behind         0.4        BSIT.409      -1.7       2.1

  TC20          Bottom of SIT EBOX Behind       0.7        BSIT.432      -1.8       2.5

  TC21          Bottom of SIT EBOX Behind       0.3        BSIT.432      -1.8       2.1

  TC22          Under SIT Collimator exterior   -34.0      BSIT.427      -32.2      1.9
                Behind                                                              

  TC23          Right Side of SIT Collimator    -32.9      BSIT.419      -31.9      1.0
                Behind                                                              

  SEPT AHEAD NS                                                                     

  TC #          Location                        Measured   NODE          Predicts   DELTA T

  TC24          Front of SEPTA on Bracket NS    -31.4      SEPTNS.93     -30.8      0.6

  TC25          Front of SEPTA Telescope NS     -31.6      SEPTNS.64     -31.0      0.6

  TC26          Front of SEPTA Telescope NS     -31.8      SEPTNS.21     -31.7      0.0

  TC27          Front of SEPTA Telescope NS     -31.8      SEPTNS.21     -31.7      0.0

  TC28          Front of SEPTA on Bracket NS    -30.8      SEPTNS.106    -30.9      0.1

  TC29          Front of SEPTA on Bracket NS    -30.9      SEPTNS.94     -29.5      1.4

  TC30          Front of SEPTA EBOX NS          -28.6      SEPTNS.35     -25.9      2.7

  TC31          Back of SEPTA on Bracket NS     -31.1      SEPTNS.105    -30.8      0.3

  TC32          Back of SEPTA Telescope NS      -31.3      SEPTNS.82     -31.0      0.3

  TC33          Back of SEPTA Telescope NS      -32.1      SEPTNS.28     -31.7      0.4

  TC34          Back of SEPTA Telescope NS      -32.1      SEPTNS.28     -31.7      0.4

  TC35          Back of SEPTA on Bracket NS     -31.3      SEPTNS.92     -30.9      0.5

  TC36          Back of SEPTA on Bracket NS     -30.2      SEPTNS.109    -29.5      0.7

  TC37          Back of SEPTA EBOX NS           -28.1      SEPTNS.40     -25.9      2.2

  TC38          Bottom of SEPTA Bracket NS      -28.8      SEPTNS.109    -29.5      0.7

  TC39          Bottom of SEPTA Bracket NS      -29.7      SEPTNS.94     -29.5      0.2

  TC40          Radiator Side of SEPTA NS       -28.8      SEPTNS.39     -26.1      2.7

  TC106         Bottom of SEPTA NS              -29.0      SEPTNS.36     -25.2      3.8

  TC107         Bottom of SEPTA NS              -27.8      SEPTNS.36     -25.2      2.6

  SEPT BEHIND                                                                       
  NS                                                                                

  TC #          Location                        Measured   NODE          Predicts   DELTA T

  TC108         Front of SEPTB on Bracket NS    -29.6      SEPTNSB.93    -31.7      2.1

  TC109         Front of SEPTB Telescope NS     -29.8      SEPTNSB.64    -31.8      2.0

  TC110         Front of SEPTB Telescope NS     -30.1      SEPTNSB.21    -32.5      2.4

  TC111         Front of SEPTB Telescope NS     -29.9      SEPTNSB.21    -32.5      2.6

  TC112         Front of SEPTB on Bracket NS    -29.0      SEPTNSB.106   -31.7      2.7

  TC113         Front of SEPTB on Bracket NS    -28.3      SEPTNSB.94    -30.4      2.1

  TC114         Front of SEPTB EBOX NS          -26.8      SEPTNSB.35    -26.8      0.0

  TC115         Back of SEPTB on Bracket NS     -29.3      SEPTNSB.105   -31.6      2.4

  TC116         Back of SEPTB Telescope NS      -29.7      SEPTNSB.82    -31.9      2.1

  TC117         Back of SEPTB Telescope NS      -30.6      SEPTNSB.28    -32.6      2.0

  TC118         Back of SEPTB Telescope NS      -30.7      SEPTNSB.28    -32.6      1.9

  TC119         Back of SEPTB on Bracket NS     -29.3      SEPTNSB.92    -31.8      2.5

  TC120         Back of SEPTB on Bracket NS     -30.0      SEPTNSB.109   -30.3      0.4

  TC121         Back of SEPTB EBOX NS           -27.4      SEPTNSB.40    -26.8      0.6

  TC122         Bottom of SEPTB Bracket NS      -28.6      SEPTNSB.109   -30.3      1.7

  TC123         Bottom of SEPTB Bracket NS      -28.5      SEPTNSB.94    -30.4      1.9

  TC126         Radiator Side of SEPTB EBOX NS  -27.3      SEPTNSB.39    -27.0      0.3

  TC124         Bottom of SEPTB NS              -26.5      SEPTNSB.36    -26.1      0.3

  TC125         Bottom of SEPTB NS              NA         SEPTNSB.36    -26.1      NA
  ------------- ------------------------------- ---------- ------------- ---------- --------

**TABLE 3: Comparison of SIT AHEAD Test vs. Analysis Results (°C)**

  ------------- ---------------------------- ---------- ------------ ---------- --------
  **Survival                                                                    
  Balance**                                                                     

  TC #          Location                     Measured   NODE         Predicts   DELTA T

  TC1           Front of SIT EBOX Ahead      -29.1      ASIT.444     -29.9      0.8

  TC2           Front of HVPS Ahead          -28.5      APOWER.325   -29.6      1.1

  TC3           Right Side of SIT EBOX Ahead -28.1      ASIT.431     -29.8      1.7

  TC4           Right Side of HVPS Ahead     -27.8      APOWER.328   -29.6      1.8

  TC5           Right Side of SIT Telescope  -15.4      ASIT.413     -16.0      0.6
                Ahead                                                           

  TC6           Top of SIT Telescope Ahead   -15.4      ASIT.433     -16.3      0.9

  TC7           Top Front of SIT Telescope   -14.4      ASIT.425     -16.0      1.6
                Ahead                                                           

  TC8           Top of SIT Collimator Ahead  -12.7      ASIT.437     -14.5      1.8

  TC9           Lengthened Side SIT          -15.5      ASIT.417     -13.8      1.7
                Collimator Ahead                                                

  TC10          Front of SIT Telescope Ahead -17.3      ASIT.429     -15.9      1.4

  TC11          Top of SIT Telescope Ahead   -15.8      ASIT.433     -16.3      0.5

  TC12          Back of SIT Telescope Ahead  -16.7      ASIT.415     -16.2      0.5

  TC13          Left Side of SIT EBOX Ahead  -29.9      ASIT.445     -30.2      0.3

  TC14          Left Side of HVPS Ahead      -28.7      APOWER.327   -29.6      0.9

  TC15          Left Side of SIT Telescope   -18.5      ASIT.435     -16.5      2.0
                Ahead                                                           

  TC16          Front of SIT Telescope Ahead -17.8      ASIT.429     -15.9      1.9

  TC17          Back of SIT Telescope Ahead  -16.9      ASIT.415     -16.2      0.7

  TC18          Back of HVPS Ahead           -28.0      APOWER.326   -29.6      1.7

  TC19          Back of SIT EBOX Ahead       -29.1      ASIT.409     -29.9      0.8

  TC20          Bottom of SIT EBOX Ahead     -29.6      ASIT.432     -29.8      0.2

  TC21          Bottom of SIT EBOX Ahead     -32.9      ASIT.432     -29.8      3.1

  TC22          Under SIT Collimator         -12.6      ASIT.427     -12.1      0.5
                exterior Ahead                                                  

  TC23          Heater Side SIT Collimator   -4.0       ASIT.419     -5.3       1.3
                Ahead                                                           

  **Hot                                                                         
  Operational                                                                   
  Balance**                                                                     

  TC #          Location                     Measured   NODE         Predicts   DELTA T

  TC1           Front of SIT EBOX Ahead      3.2        ASIT.444     5.1        1.9

  TC2           Front of HVPS Ahead          3.1        APOWER.325   5.1        2.0

  TC3           Right Side of SIT EBOX Ahead 4.7        ASIT.431     5.3        0.6

  TC4           Right Side of HVPS Ahead     3.6        APOWER.328   5.2        1.6

  TC5           Right Side of SIT Telescope  -4.1       ASIT.413     -0.6       3.5
                Ahead                                                           

  TC6           Top of SIT Telescope Ahead   -3.4       ASIT.433     -0.9       2.5

  TC7           Top Front of SIT Telescope   0.4        ASIT.425     -0.4       0.7
                Ahead                                                           

  TC8           Top of SIT Collimator Ahead  6.6        ASIT.437     3.9        2.7

  TC9           lengthed Side SIT Collimator 4.8        ASIT.417     4.6        0.2
                Ahead                                                           

  TC10          Front of SIT Telescope Ahead -2.9       ASIT.429     -0.4       2.5

  TC11          Top of SIT Telescope Ahead   -4.6       ASIT.433     -0.9       3.7

  TC12          Back of SIT Telescope Ahead  -4.5       ASIT.415     -0.9       3.6

  TC13          Left Side of SIT EBOX Ahead  1.8        ASIT.445     4.7        2.9

  TC14          Left Side of HVPS Ahead      2.6        APOWER.327   5.1        2.5

  TC15          Left Side of SIT Telescope   -4.4       ASIT.435     -1.3       3.1
                Ahead                                                           

  TC16          Front of SIT Telescope Ahead -3.7       ASIT.429     -0.4       3.3

  TC17          Back of SIT Telescope Ahead  -4.2       ASIT.415     -0.9       3.3

  TC18          Back of HVPS Ahead           3.2        APOWER.326   5.1        2.0

  TC19          Back of SIT EBOX Ahead       3.6        ASIT.409     5.1        1.4

  TC20          Bottom of SIT EBOX Ahead     2.8        ASIT.432     5.3        2.5

  TC21          Bottom of SIT EBOX Ahead     -0.4       ASIT.432     5.3        5.7

  TC22          Under SIT Collimator         6.8        ASIT.427     6.5        0.3
                exterior Ahead                                                  

  TC23          Heater Side SIT Collimator   17.3       ASIT.419     15.3       1.9
                Ahead                                                           
  ------------- ---------------------------- ---------- ------------ ---------- --------

**[Thermal Vacuum Results]{.underline}**

The TV test consisted of six operational qualification cycles, a cold
turn-on, a hot turn-on and both a hot/cold survival soak were
accomplished. The SIT Behind telescope surface barrier detector was not
working correctly and a replacement was not available. However, the TV
test was carried out testing the function of all but the failed detector
on the SIT Behind instrument. Additional testing of SIT Behind will
occur when a replacement detector becomes available. The SIT Ahead
instrument has satisfactorily completed the thermal vacuum test program
and has met all of the requirements spelled out in the STEREO-GSFC-002.C
test plan and STEREO Environment Definition, Observatory, Component and
Instrument Test Requirements Document.

The test setup was carried out according to the STEREO-GSFC-002.C test
plan. Two units were mounted side by side on a heat exchanger (see
Figure 6).

To provide good thermal contact to the cold plate the flight Ultem
stand-offs below the mounting feet were omitted from the bottom plate of
the E-Boxes.

![](media/image6.wmf){width="5.882638888888889in"
height="4.804861111111111in"}

Figure 6 SIT TV Test Set-up

![](media/image7.png){width="5.998611111111111in"
height="4.026388888888889in"}

1 = Stabilize, Soak 1Hour and Test Concurrently.

2 = Stabilize, Turn On, Soak 1Hour and Test Concurrently.

**Figure 7: SIT Thermal Vacuum Test Temperature Profile**

![](media/image8.wmf){width="5.995833333333334in"
height="4.107638888888889in"}

**Figure 8: SIT Thermal Vacuum Test Temperature Data**

**Table 5: SIT** Thermal Vacuum Soak Temperatures

  ---------------------- --------- -------- -------- --------- ----------
  Component              Bakeout   Hot Srv  Hot Op   Cold Srv  Cold Op
                         (^O^C)    (^O^C)   (^O^C)   (^O^C)    (^O^C)

  SIT EBOX               50        50       45       -40       -30

  SIT Telescope          32        32       30       -40       -30
  ---------------------- --------- -------- -------- --------- ----------

**[Conclusions]{.underline}**

-   The SIT Ahead instrument has satisfactorily completed the thermal
    vacuum test program.

-   The SIT Behind instrument will undergo addition TV testing, to
    complete the thermal vacuum test program, when the surface barrier
    detector is replaced.

-   The thermal balance test correlation has successfully verified the
    SIT instruments thermal models and the thermal conductance of the
    isolators.

-   Thermal coatings chosen for the SEPT/SIT instruments are adequate
    for maintaining temperatures in the acceptable range.

-   The SIT qualification test has been conducted from --40ºC to +50ºC
    (survival), which indicates significantly more margin at the hot end
    than for the cold case for the SIT Ahead instrument. When making the
    SIT Ahead instrument's flight MLI blanket, the radiator area was
    reduced to provide additional heater margin at the cold end with the
    minimum expected flight voltage.

-   The SIT qualification test has been conducted from --30ºC to +30ºC
    (operational), which for the SIT Ahead instrument, again indicates
    significantly more margin at the hot end than for the cold case. The
    reduced radiator area will provide additional heater margin at the
    cold end.

-   All the SEPT units proved to have adequate margin at both the hot
    and cold ends.