5.8 The First Space Flight Test and Its Results
385
Fig. 5.31 Distribution of eight candidate observation objects on the celestial sphere
to the center of the Earth’s disk. The scanning observation mode is used to evaluate
the space background noise, through the scanning belt formed as the satellite moves
along the orbit and the detector points to a sky area. The candidate object observation
mode is a customized observation mode, by using which the X-ray detector TSXS
or HTPC points to one of the eight candidate observation objects for carrying out
the X-ray detections. The arbitrary target-pointing mode is similar to the third mode,
but for the mode, the angular position parameters of the target celestial bodies are
uploaded to the satellite through the ground TT&C stations at any time according
to the actual observation plan, rather than those stored in the onboard memory in
advance. Obviously, besides the eight candidate observation objects, the XPNAV-1
satellite can arbitrarily observe other X-ray sources, such as the center of the Milky
Way system, and the supernova remnants.
At 7:42 Beijing time on November 10, 2016, the XPNAV-1 satellite was launched
with the solid-fueled launch vehicle Long March 11 at Jiuquan Satellite Launch
Center, China. After the launch vehicle took off ten minutes, the satellite was separated from it to enter into the predetermined orbit over the equator in the Indian
Ocean. The XPNAV-1 orbit is designed as the Sun synchronization orbit with the
local time of 6:00 AM at the descending node, the orbital altitude of 510 km and
the inclination of 97.4°. After the in-orbit tests for a week, the XPNAV-1 satellite
started to enter the stage of scientific test missions on November 18, 2016. From the
observation data analysis, it is shown that the SNR of the observation data from the
TSXS is higher than that of the observation data from the HTPC, so the observation
and test results obtained by using the TSXS are mainly discussed and demonstrated
in this section.
385
Fig. 5.31 Distribution of eight candidate observation objects on the celestial sphere
to the center of the Earth’s disk. The scanning observation mode is used to evaluate
the space background noise, through the scanning belt formed as the satellite moves
along the orbit and the detector points to a sky area. The candidate object observation
mode is a customized observation mode, by using which the X-ray detector TSXS
or HTPC points to one of the eight candidate observation objects for carrying out
the X-ray detections. The arbitrary target-pointing mode is similar to the third mode,
but for the mode, the angular position parameters of the target celestial bodies are
uploaded to the satellite through the ground TT&C stations at any time according
to the actual observation plan, rather than those stored in the onboard memory in
advance. Obviously, besides the eight candidate observation objects, the XPNAV-1
satellite can arbitrarily observe other X-ray sources, such as the center of the Milky
Way system, and the supernova remnants.
At 7:42 Beijing time on November 10, 2016, the XPNAV-1 satellite was launched
with the solid-fueled launch vehicle Long March 11 at Jiuquan Satellite Launch
Center, China. After the launch vehicle took off ten minutes, the satellite was separated from it to enter into the predetermined orbit over the equator in the Indian
Ocean. The XPNAV-1 orbit is designed as the Sun synchronization orbit with the
local time of 6:00 AM at the descending node, the orbital altitude of 510 km and
the inclination of 97.4°. After the in-orbit tests for a week, the XPNAV-1 satellite
started to enter the stage of scientific test missions on November 18, 2016. From the
observation data analysis, it is shown that the SNR of the observation data from the
TSXS is higher than that of the observation data from the HTPC, so the observation
and test results obtained by using the TSXS are mainly discussed and demonstrated
in this section.