USMP-3 Microgravity Data


Microgravity data shown below is PRELIMINARY data, subject to changes once further analysis has been performed. The data result from CCD images captured approximately every 90 seconds during dendrite growth. As the resolution of these images are not sufficient to determine dendrite shape characteristics, only the growth velocity is presented here.
The IDGE experiment is broken up into three phases. The data from each phase is in its own table below.
 

Sample Material Tests
These are initial tests to assess the purity of the sample after launch, and determine the melting temperature.
        Melting Plateau:  Shape of plot indicates sample purity has been maintained
        Freezing Plateau: Melting/Freezing temperature = 58.095 C

Phase 1
Accumulation of Dense Data
This data corresponds to dendrite crystals grown under "quality" microgravity conditions. The objective during this phase of the experiment is to obtain data points that may be used in conjunction with the data obtained during USMP-2, to further densify the range of supercoolings where characterization is desired.
Velocities Based on View 1
     Cycle            Supercooling           Velocity    
     Num.             ± 0.002(K)             (microns/s)                        
     ___________________________________________________________
        1               1.10                    210             
        2               0.54                    34
        3               0.76                    79
        4               0.60                    45

Phase 2
Science of Opportunity
This data corresponds to dendrite crystals grown with CCD images only. This data will later be used in conjunction with g-level measurements to assess the affect that convection has upon dendrite growth rates.
Velocities Based on View 1 Velocities Based on View 1
     Cycle             Supercooling          Velocity       
     Num.              ± 0.002(K)           (microns/s)                 
     ___________________________________________________________
        5               0.18                    3.2             
        6               0.26                    6.2
        7               0.36                    14.3
        8               0.18                    3.3
        9               0.26                    6.2
        10              0.36                    14.7
        11              0.18                    3.4
        12              0.26                    6.8
        13              0.36                    13.4
        14              0.18                    3.3
        15              0.26                    7.1
        16              0.36                    14.3

Phase 3
Primary Science
This data corresponds to dendrite crystals grown under "quality" microgravity conditions. The objective during this phase of the experiment is to obtain a large number of measurements at each of three supercoolings. This information will be used to characterize the three-dimensional shape of dendrite tips.
     Cycle         Supercooling                Velocity       
     Num.          ± 0.002(K)                 (microns/s)                  
     ___________________________________________________________
        37              0.46                    25.06
        38              0.46                    25.94   
        39              0.46                    25.83
        40              0.46                    24.07
        41              0.46                    25.46
        42              0.46                    27.02
        43              0.46                    25.58
        44              0.46            
        45              0.46                    27.72
        46              0.46                    27.15
        47              0.46                    22.30
        48              0.46                    24.98
        49              0.46                    25.89
        50              0.46                    25.32
        51              0.46                    26.15
        52              0.46                    25.27
        53              0.46                    24.10
        54              0.46                    25.87
        55              0.46                    24.14
        56              0.46                    25.85

        57              0.65                    53.14
        58              0.65                    55.63
        59              0.65                    52.34
        60              0.65                    53.11
        61              0.65                    52.63
        62              0.65                    56.46
        63              0.65                    52.52
        64              0.65                    55.90
        65              0.65                    54.28
        66              0.65                    50.89
        67              0.65                    53.45
        68              0.65                    51.79
        69              0.65                    56.94
        70              0.65                    54.55
        71              0.65                    54.26
        72              0.65                    55.21
        73              0.65                    53.01
        74              0.65                    52.44
        75              0.65                    54.62
        76              0.65                    53.72

        77              0.26                    5.36
        78              0.26                    6.56
        79              0.26                    6.96
        80              0.26                    6.75
        81              0.26                    6.20
        82              0.26                    5.45
        83              0.26                    7.00
        84              0.26                    6.98
        85              0.26                    6.42
        86              0.26                    6.11