Transcript 3.3 - Indico@IHEP

eXTP Accomodation Study
Hong Bin , Zhang Long
Institute of Spacecraft System Engineering . CAST
Oct 27th , 2015
Outline
1
The XTP Remarks
2
The eXTP Requirements
3
WFM Configuration
4
LAD Configuration
5
Discussion and Summary
1.The XTP Remarks
XTP Instruments
 High energy X-ray Focusing Array (5 Units) FL=5500mm
 Low energy X-ray Focusing Array (10 Units) FL=4500mm
 High energy Collimating Array (2 Units) or LAD (20 Units, 1.5m2)
 Wide Field Camera (1 Unit)
1.The XTP Remarks
Launch Vehicles
Lauch Vehicles
LM-3C
Lauch Site
Xichang
Payload Fairing
4200F
The 4200F fairing has an
external diameter of
4,200 mm, a total height
of 9,381 mm ,is
the biggest one in the
series of the LM-3 family.
1.The XTP Remarks
Observation Mode
a. The –X axis points to the specific
targets in the inertial space ；
targets
goals
b. The sun vector is constrainted in XOZ
plane and in a obtuse angle with the +Z
axis；
c. The normal vector of solar array shall
be parallelled to the sun vector by
rotating the solar array；
d. Altitude maneuver is performed to
observation continually according to the
user‘s plan of observation.
X
O
Z
面
Ψ
Y
O
Z
X
S
Suns
1.The XTP Remarks
XTP System Parameters
Item
Requirement (XTP)
Mass
3500 kg
Power Budget
3200 W
(include short-term power consumption)
Orbit
550km, 28°(14°backup)
Observation Mode
Pointing Observation
Accuracy of attitude pointing
< 0.01° (3σ)
Accuracy of attitude
measurement
< 0.002° (3σ)
Attitude maneuver
0.005°/s (3σ)
1’/500s (3σ)
<10min in +/-30degree, 20 times/year
Life time
5 years
Attitude stabilization
2.The eXTP Requirements
eXTP Instruments
 High energy X-ray Focusing Array(5 Units) FL= 4500mm
 Low energy X-ray Focusing Array (10 Units) FL= 4500mm
 LAD (40 Units——4 panles 3 m2)
 Wide Field Monitor (2 pairs)
2.The eXTP Requirements
eXTP Anticipate Parameters
Item
eXTP Anticipate Parameters
Mass
3700 kg
Power Budget
3600 W
(include short-term power consumption)
Orbit
550km 28°(14°？)
Observation Mode
Pointing Observation
Accuracy of attitude pointing
< 0.01° (3σ)
Accuracy of attitude
measurement
< 0.002° (3σ)
Attitude maneuver
0.005°/s (3σ)
1’/500s (3σ)
<10min in +/-30degree, 20 times/year
Life time
5 years
Attitude stabilization
It’s impossible to decrease the orbit inclination(less than 14°).
3. WFM Configuration(2 pairs)
WFM Configuration（2 pairs）
 First, the WFM is placed on the optical bench where is blank;
 Part of the cameras would be obstructed by the sunshield In
place B ;
 No space enough to
mount the camera due
B
to the two star trackers
in place A and C, and the
fairing is another
A
C
reasons;
 So there is only one
place could mount the
WFM;
D
√
3. WFM Configuration(2 pairs)
WFM Sunshield-By Satellite Structure
 place D is an ideal place to
mount the WFM because the
tube could act as the
sunshield which could protect
the masks and detectors from
the solar radiation;
 Two anti-sun camera pairs are
mounted on place D, inclined
by 0°, 60°;
 With respect to the optical
axis (+15°, -15°，+30°)
4. LAD Configuration(4 panels)
LAD Configuration（40 modules）




Two panels per side;
Each panels assembled 10 modules;
Folded on the ground;
Stretched out in two opposite direction In
orbit;
 The temperature could be
under control if we could
protect the detector from
the solar radiation,
according to the results of
thermal analysis.
 The sunshield is required.
on the ground
In orbit
4. LAD Configuration(4 panels)
LAD Sunshield Dimensions
 Sunshield acreage requirement：40 m2 (all optics in the shadow);
 The temperature of the LAD could be controlled at -20℃~-10℃;
 The atmospheric drag is increased , so it needs more than 40kg
fuel to maintain the orbit height.
More details talked by Mr Li Xiao！
4. LAD Configuration(4 panels)
LAD Structure and Mechanical
structure
Supports the 40 Units LAD module ;
Made of CFRP;
Permit the alignment of the LAD
module;
Stiff enough to avoid deformations
due to accelerations and thermal
stresses.
mechanical
Withstand launch loads;
Release the panels in obit ;
deploy and latch in the final
position.
More details talked by Mr Li Xiao！
5. Dicussion and Summary
 It’s impossible to decrease the orbit inclination ( less than 14°).
 It’s feasible to mount 2 pairs WFM and 40 LAD Module.
 The sunshield is required to fufill temperature requirements of
the LAD.
 With the sunshield, the temperature of LAD could be controlled
at -20℃~-10℃.
 The sunshield would increase the atmospheric drag, more fuel is
required to maintain the orbit height.
Thank you for Your
attention！