TAUVEX Early Ops
From Tauwiki
This document gives a summary of the events soon after launch until First Light.
Contents |
[edit] Survival mode
17 minutes after launch, battery power will be available using which we can set TAUVEX to survival mode that uses 15W of power. This can be achieved by relaying a command to TAUVEX to switch on the DC/DC converters.
[edit] Full power
32 minutes after launch, the solar panels will be opened and TAUVEX will now have full power. Now TAUVEX can be turned on. This will put TAUVEX in a normal temperature regime with default system settings.
[edit] Outgassing
88 minutes after launch (56 minutes after Full power), we have 1553 communication and this will enable us to send any command to TAUVEX and so we can give the command for starting the outgassing at this stage. The first three weeks of operations will be devoted to outgassing, during which the power is used to raise the temperature above normal values. The outgassing will start even before the spacecraft reaches its final orbit.
[edit] scientific data testing
After outgassing, the data transmission of the instrument will be tested using synthetic data calibration. The HVPS will not be turned on during this process.
[edit] Offset measurements
The W, S, Z offsets are tested with the HVPS turned off.
[edit] Dark count measurement
Soon after these initial tests High Voltage Power Supply is switched on, with the filter in the closed position. During this phase, measurements of the dark counts will be taken for 1 orbit. After the initial measurement of dark counts during the PV phase, the dark counts will be measured once every 2-3 months.
[edit] First Light
After the 1st orbit the 3 telescopes are made to point to some area of the sky, each with 3 different filters. The first observation using TAUVEX will be of the South Celestial Pole (SCP). Since the scan rate is minimum at the poles we can observe this location for a longer period. This location contains several stars many of which are A-type and hence UV emitters. Given below is a list of stars in the region together with the predicted counts in the BBF filter of TAUVEX.
| Tycho no. | R.A.(hrs.) | Dec(deg.) | BBF |
| 9502 | 0.33 | -89.81 | 17.32 |
| 9503 | 3.80 | -89.77 | 13.95 |
| 9504 | 5.53 | -89.71 | 13.85 |
| 9505 | 6.03 | -89.67 | 15.23 |
| 9505 | 7.05 | -89.53 | 13.56 |
| 9518 | 8.07 | -89.55 | 16.15 |
| 9518 | 8.41 | -89.74 | 13.39 |
| 9518 | 8.97 | -89.83 | 13.39 |
| 9518 | 9.94 | -89.78 | 7.92 |
| 9519 | 11.51 | -89.51 | 12.63 |
| 9520 | 12.64 | -89.61 | 12.83 |
| 9520 | 13.28 | -89.87 | 12.57 |
| 9520 | 13.44 | -89.54 | 12.47 |
| 9521 | 14.59 | -89.77 | 14.85 |
| 9521 | 14.65 | -89.56 | 13.13 |
| 9521 | 14.84 | -89.80 | 16.08 |
| 9536 | 21.80 | -89.62 | 12.41 |
| 9536 | 21.93 | -89.62 | 12.66 |
| 9537 | 23.05 | -89.66 | 12.06 |
The telescope filter combination for this observation:
T1||SF1
T2||SF2
T3||SF3
In the shade(~2hrs), the telescope filter combination:
T1||SF1
T2||BBF
T3||SF3
