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CHAPTER 5
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CHAPTER 5
MECHANICAL/ELECTRICAL INTERFACE
The interface between LV and SC consists of mechanical and electrical interfaces.
Through mechanical interface, the SC is mated with the LV mechanically, while the
electrical interface functions to electrically connect the LV with SC.
In this chapter, interfaces of LM-2E/ETS and LM-2E/EPKM are focused on.
Part A: Mechanical/Electrical Interface Provided by LM-2E/ETS
A5.1 LM-2E/ETS Mechanical Interface
A5.1.1 Summary
LM-2E/ETS provides two types of mechanical interface: Type A and Type B. Type A
mechanical interface is used for connecting SCs laterally, while Type B for
connecting SCs from their bottom.
A5.1.2 Type A Mechanical Interface
The SCs are connected to the dispenser laterally, and the dispenser is bolted on the
main structure of OMS that is connected with payload adapter by clampband. See
Figure A5-1.
Note: 1) OMS stands for orbital maneuver system;
2) ETS consists of OMS and Dispenser;
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Spacecraft
Dispenser
Spacecraft
Orbital Maneuver System (OMS)
Payload Adapter
Figure A5-1 Type A Mechanical Interface
z
Type A SC Dispenser
The SC dispenser functions to fasten and release the satellites. The typical type A SC
dispenser is composed of a cylinder and a cone made from frame-skin
semi-monocoque structure. The specific design is program dependent.
The dispenser is fixed on the main structure of OMS by bolts. The SCs are connected
with the dispenser by low-shock explosive nuts and separation springs.
See Figure A5-2a&b.
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A
Explosive Nut
Flight Direction
TBD
Separation
Spring
SC
TBD
Dispenser
TBD
B
Direction A
Direction B
Dispenser
Dispenser
I
SC
A
A
III
SC
II
Figure A5-2a Type A SC Dispenser
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z
Separation Device for Type A Dispenser
The SC/LV separation device consists of explosive nuts and separation springs as
shown in Figure A5-2b. The explosive nuts are used for locking and unlocking the
SCs. Catchers can collect the separated bolts. The separation springs includes springs,
bracket, pushing rod, etc. The device can provide a SC/LV separation velocity
according to user's requirements.
Detail II
Detail I
C
Detail III
View C
Separation Plane
Interface Plane
Spheric Head
Explosive
Nut
TBD
TBD
Bolt Catcher
100
Figure A5-2b Separation Device for Type A SC dispenser
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A5.1.3 Type B Mechanical Interface
The SCs are connected to the dispenser from their bottom, and the dispenser is fixed
on the main structure of OMS, which is connected with payload adapter by
clampband. See Figure A5-3. There are 4 SC adapters fixed on the main structure of
the typical type B dispenser. The SCs are mounted on the SC adapters by low-shock
explosive nuts and separation springs.
Spacecraft
Spacecraft
Dispenser
Orbit Maneuver System
Payload Adapter
Figure A5-3 Configuration of Type B Mechanical Interface
z
Type B Dispenser
The type B dispenser is a short reverse cone structure with four SC adapters as shown
in Figure A5-4a. The SC adapter is fastened to the SC adapter at its bottom using
explosive nuts. All the separation system except for bolt catcher is attached on the SC
adapter.
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SC Adapter
II
I
III
I
IV
Figure A5-4a Type B Dispenser (1)
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Detail I
A
A
Section A-A
SC Adapter
Separation
Spring Bracket
Figure A5-4bType B Dispenser (2)
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z
Separation System
The separation system consists of explosive nuts and separation springs. See Figure
A5-4c. The explosive nuts are used for locking and unlocking the SCs. The separation
springs includes springs, bracket, pushing rod, etc. The catcher can collect the
separated bolts. The separation system can provide a SC/LV separation velocity
according to user's requirements.
SC
Bolt
Catcher
SC/LV Separation Plane
Explosive
Nut
Separation Spring
Separation Spring
Bracket
Figure 5-4c Separation System for Type B Dispenser
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A5.2 LM-2E/ETS Electrical Interface
The SC is electrically connected with SC's electrical ground support equipment
(EGSE) through In-flight-disconnectors (IFDs) and umbilical cables provided by LV
side. By using of EGSE and the umbilical cables, SC team can perform wired testing
and pre-launch control to the SC, such as SC power-supply, on-board battery charging,
wired-monitoring on powering status and other parameters.
A5.2.1 In-Flight-Disconnectors (IFDs)
z
Quantity
Typically, there are two IFDs mounted on the dispenser for each SC. The detailed
location will be coordinated between SC and LV sides and finally defined in ICD.
z
IFD Supply
Generally, the IFDs are selected and provided by the user. CALT is responsible to
solder IFDs to the umbilical cables. The necessary operation and measurement
description shall also be provided. (If the user selects the China-made connectors,
CALT will provide the halves installed on the SC side.). The available China-made
connectors are YF8-64 (64 pins), FD- 20(20 pins), FD-26(26 pins), FD-50(50 pins),
etc.
z
Separation signal through IFDs
There are four break-wires on the two IFDs for each SC, which generate SC/LV
separation signals. The SC will receive the SC/LV separation signals once the
break-wires circuitry break while SC/LV separates.
In the same way, there are four break-wires on the IFDs. The IFDs will send the
SC/Dispenser separation signal to LV once the break-wires circuitry break while
SC/Dispenser separates. This separation signal will be sent to LV’s telemetry system
through EY1 interface. The break-wire’s allowable current: ≤100mA, allowable
voltage: ≤30V.
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A5.2.2 Umbilical System
The umbilical system consists of onboard-LV Parts and ground parts. Refer to Figure
A5-5 and Figure A5-6. The cable from Launch Control Console (LCC) to Umbilical
Tower, EB26/EB36, BOX3, BOX4, and Power-supplies 1&2 are the common for
different missions. The onboard-LV cable, as well as ground cable from WXTC to ED
13,14&15 and BOX1 & BOX2, will be designed for dedicated SC according to user's
needs. In order to assure the quality of the product, the umbilical system will be
provided to the user after pre-delivery acceptance test and insulation/conductivity
checkouts in the launch site.
Dispenser
J12
P12 Pn2
SC1
Jn2
SCn
J11 P11
EC1
Pn1 Jn1
EC2
Payload Adapter
WXTC
To GSE
Figure A5-5 LM-2E/ETS Onboard-LV Electrical Interface
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SC1
SCn
J11
J12
Jn1
Jn2
P11
P12
Pn1
P n2
Onboard-LV
Umbilical Part
EC1
EY1
EC2
G1
WXTC
EB26
ED13 ED14 ED15
BOX 1
ED23
X1
ED22
ED24
Power
Supply1
EB37
EB36
BOX3
EB33
EB46
Ground Umbilical Part
Power
Supply2
EB56
X31
BOX 2
P5
ED43
ED42
ED44
P6
P7
DLWX
P1
J1
SC Console
P2
J2
P3
J3
WK
BOX4
P8
WZT
P4
J4
SC RPS
Figure A5-6 Onboard-LV and Ground Umbilical System
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A5.2.2.1 Onboard-LV Umbilical Cable
z
Composition
The Onboard-LV cable net comprises the cables from the IFDs to WXTC. These
umbilical cables will fly with LV.
Whereas:
Code
P11,P12…Pn1,Pn2
EC1、EC2
EY1
WXTC
G1
Description
LV/SC electrical connectors at LV side which is
crimp-connected to the cables.
Technological interfaces between Dispenser and OMS.
Interface between umbilical cable and LV TM system, through
which the LV/SC separation signal is sent to LV TM system
Umbilical cable connector (LV-Ground)
Grounding points to overlap the shielding of wires and the shell
of LV
Refer to Figure A5-6.
z
Umbilical Cable Design
SC side shall specify characteristics of the IFDs. The specific contents are pin
assignment, usage, maximum voltage, maximum current, one-way maximum
resistance etc. CALT will design the umbilical cable according to the specified
requirements.
z
Types and Performance of Umbilical Cable
Generally, ASTVR and ASTVRP wires are adopted for the onboard-LV cable net:
ASTVR, 0.5mm2, fiber-sheath, PVC insulation;
ASTVRP, 0.5mm2, fiber-sheath, PVC insulation, shielded.
For both cables, their working voltage is ≤500V and DC resistance is 38.0Ω/km
(20°C). The single core or cluster is shielded and sheathed.
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A5.2.2.2 Ground Umbilical System
z
Composition
The ground umbilical cable net consists of umbilical cable connector (WXTC), cables,
box adapters, etc. Refer to Figure A5-6.
Whereas:
Code
WXTC
BOX1
BOX2
BOX3
BOX4
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Description
WXTC is umbilical cable connector (LV-Ground) whose female half
(socket) is installed at the wall of the VEB, while the male half (pin) is
attached to the top end of ground cable. The disconnection of WXTC is
electrically controlled. (The disconnection is powered by BOX 3 and
controlled by BOX 4. In the mean time, forced disconnection is also used
as a spare separation method.) Generally, WXTC disconnects at about
8min prior to launch. If the launch was terminated after the
disconnection, WXTC could be reconnected within 30min.
The SC should switch over to internal power supply and cut off ground
power supply at 5 minutes prior to WXTC disconnection. Therefore,
during disconnection only a low current monitoring signal (such as 30V,
≤100mA) is permitted to pass through the WXTC.
BOX 1 is a box adapter for umbilical cable that is located inside the
Payload Cable Measurement Room on the umbilical tower. Refer to
Chapter 7. (If needed, BOX 1 can provide more interfaces for the
connection with SC ground equipment.)
BOX 2 is another box adapter for umbilical cable that is located inside
the Underground Power-supply Room. Refer to Chapter 7. Other SC
ground support equipment (RPS, Console, etc.) are also located inside the
Underground Power-supply Room.
This is a relay box for the disconnection of the umbilical cable. BOX 3 is
located inside the Underground Power-supply Room. Box 3 is powered
by 2 DC regulated power supply sets. These two power supply sets are in
“working-state” sparing to each other.
BOX 4 is located inside the Payload Cable Measurement Room . It is for
the control of the pre-launch disconnection of SC umbilical cables.
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z
Interface on Ground
Generally, there are four interfaces on ground, namely, two for SC Console
(P1/J1&P2/J2), and the other two for SC power supply (P3/J3&P4/J4). SC side will
define the detailed requirement of ground interfaces. Those connectors (P1,P2,P3,P4)
to be connected with SC ground equipment should be provided by SC side to LV side
for the manufacture of cables.
Location
Code
LV side
interfaces
P1
P2
P3
P4
Specification
Quantity
To be defined by SC side
2
2
2
2
If LV side couldn’t get the connectors from SC side, this ground interface cable will
be provided in cores with pin marks. SC side can also provide this ground cable. The
length of this cable is about 5 meters. If so, LV side will provide the connectors to
connect with BOX 2.
z
Type & Performance of Umbilical Cable
— Single-Core Shielded Cable
Woven wire net for shielding of cable; Working voltage: ≤60V; DC resistance (20°C)
of each core: 38.0Ω/km. Function: common control and signal indicating.
— Ordinary Insulation Cable
No shielding for each core, woven tin-plated copper wire for shielding of cable;
Working voltage: ≤110V; DC resistance (20°C) of each core: 28.0Ω/km. Function:
SC's power supply and battery charging.
— Twin-twist Shielded Cable
Each twisted pair is shielded and the whole cable has a woven wire net for shielding.
Impedance: 100Ω. Function: SC data transmission and communication.
Under normal condition, the umbilical cable (both onboard-LV and ground) has a
insulation resistance of ≥10MΩ (including between cores, core and shielding, core
and LV shell)
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The umbilical system can be dedicatedly designed according to the user's
requirements.
A5.2.3 Umbilical Cable Disconnect Control
LV side is responsible for the pre-launch disconnection of umbilical cable through
BOX3 and BOX 4.
Inside the underground Power Supply Room, there are two DC regulated power
supply which will provide power for the cables. They are all in working condition
sparing to each other.
Generally, according to the count-down launch procedure, only after LV side has
received the confirmation that SC has turned to internal power and SC is normal,
could the order of umbilical cable disconnection be sent out.
A5.2.4 Anti-lightning, Shielding and Grounding
In order to assure the safety of the operations of both LV and SC, some measures have
been taken for anti-lightning, shielding and grounding.
(1) The cable has two shielding layers, the outer shielding is for anti-lightning while
the inner shielding is for anti-interference.
(2) For the cables from WXTC to BOX 2, the outer shielding (anti-lightning) has a
grounding point every 20m. These grounding measures can assure the lightning
and other inductance to be discharged immediately. The grounding locations are
either on the swing rods or the cable’s supporting brackets.
(3) The inner shield has a single grounding. The inner shields of the on-board cables
are connected to BOX 2 through WXTC. BOX 2 has a grounding pole.
(4) The inner and outer shields are insulated with each other inside the cables.
SPECIAL STATEMENT
Any signal possibly dangerous to the flight can not be sent to the SCs during the
whole flight till LV/SC separation. Only LV/SC separation can be used as the initial
reference for all SC operations. After LV/SC separation, SC side can control SC
through microswitches and remote commands.
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A5.3 RF Links
A5.3.1 RF Path
JSLC can provide RF link from technical center to the umbilical tower. Refer to
Figure A5-7.
SC T&C RF Field
Dispenser
RF Links
J12
P12
Pn2 Jn2
SC 1
BS2
SC n
J11
P11
Pn1 Jn1
EC1
EC2
EGSE
WXTC
TO BOX3
40m
BOX1
ED26
ED13 ED14 ED15
X1
ED23 ED24 ED22
BLOCKHOUSE
G1
EY1
LV Telemetry System Interface
SC CONTROL ROOM
350m
SC Console
SC RPS
CLTC is repsonisble for
connection.
J1 P1
P5
J2 P2
P6
J3 P3
P7
J4 P4
P8
X31
BOX2
ED43
ED44
ED42
Underground Umbilical Cables
Figure A5-7 RF Links in JSLC
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A5.3.2 Characteristics of RF Link
(1) Frequency
C Band:
Ku Band:
Up-link: 5925~6425 MHz
Down-link: 3700~4200 MHz
TBD
(2) Signal Level
C Band: See following table
Ku Band: TBD
Frequency
Telemetry
Command
SC Antenna
EIRP
PFD
37dBm
-85dBW/m2
EGSE
Input
-70dBm
Output
30dBm
SPECIAL STATEMENT
A mission dedicated RF working plan will be worked out. Anyway, the SC RF
equipment should be turned off during the whole flight phase of LV until all SCs are
separated form the LV hardware.
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Part B: Mechanical/Electrical Interface Provided by LM-2E/EPKM
B5.1 LM-2E/EPKM Mechanical Interface
B5.1.1 Summary
As shown in Figure B5-1, the SC adapter is connected with the SC on the top, and
bolted with EPKM on the bottom. EPKM is bolted with the interface adapter, which is
connected with LV adapter by clampband. When the clampband is released, the
EPKM/SC stack, together with interface adapter, separates from LV adapter. The SC
adapter connects with EPKM by 100 bolts. In general, SC will control the EPKM
flight as well as EPKM/SC separation. CALT is willing to satisfy other requirements.
Spacecraft
SC Adapter
EPKM
Interface Adapter
LV Adapter
Figure B5-1 LM-2E/EPKM Mechanical Interface Overview
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B5.1.2 LV Adapter
LV adapter is an 895mm-high truncated cone, whose top ring diameter is 1868mm
and bottom ring diameter is 3184mm. Refer to Figure B5-2.
0.5 A
0.4
B
0.5 A
895 1
φ1868 0.2
142.5 0.3
0.4
φ0.2
A
φ3184
1.0
39 25'
Overhead View
III
6 Separation spring brackets
2 Umbilical connector brackets
60
φ21
30
26
II
IV
45
3'
1 Rate Gyro
I
Figure B5-2 LV Adapter
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B5.1.3 Interface Adapter
LV adapter is a truncated cone, whose top ring diameter is 1868mm and bottom ring
diameter is 3184mm. Refer to Figure B5-3.
φ1760
φ1868 0.2
A
35 0.3
0.3 A
Overhead View
6 Separation
spring brackets
III
30
2 Umbilical
connector brackets
30
φ21
26
30
II
IV
I
Figure B5-3 Interface Adapter
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B5.1.4 EPKM/SC Interface
A
B
A
1170
B
2928
1886
376
117
The top ring of EPKM is connected with SC adapter with 100 bolts as shown in
Figure B5-4.
φ1256
1700
Section A-A
Section B-B
4-φ 5
100-M6-5H
0.12 B
φ0.03 A
φ1728
φ1728
Figure B5-4 EPKM/SC Interface
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B5.1.5 SC Adapter
650 0.8
CALT can provide 1194 adapter as shown in Figure B5-5a&b.
0.2
+Y
6 Separation Springs
7.5
Zoom A
60
60
A
37.5
A
-Z
+Z
50
39O 1O
2 Explosive Bolts
2 Microswitches
-Y
Figure B5-5a SC Adapter (1)
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Zoom A
5+0
.05
+Y
R603.5
+0.2
0
15
+Z
Section A-A
0.08
φ1215 0.2
A
3.2
+0.26
0
3.2
φ1192
φ1131 0.5
A
0.2515
4
15
5
1.6
5 +0.3
0
R1.5
Figure B5-5b SC Adapter (2)
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B5.1.6 SC/EPKM Separation System
CALT can provide SC/EPKM separation system. The SC/EPKM separation system
consists of clampband system and separation springs. The clampband system is used
for locking and unlocking SC adapter and the SC. The separation springs are mounted
on the SC adapter, which provides relative velocity between the SC and EPKM. Refer
to Figure B5-6a,b,c,d&e.
Non-contamination
Explosive Bolt
Lateral
Restraining Springs
Clampband
Longitudinal
Restraining Springs
Y
Separation
Spring
Z
-Z
-Y
Figure B5-6a SC/EPKM Separation System
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Clampband Dynamic
Envelope
+Z
φ1495
Clampband
Explosive Bolt
+Y
-Y
-Z
1315
Figure B5-6b Clampband Dynamic Envelope
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Detail A
SC Interface Ring
Bolt
Payload Adapter
Clampband
V Shoe
V Shoe
Detail B
C
C
Clampband
Section C-C
Explosive Bolt
100
63
Lateral
Restraining Spring
Figure B5-6c Clampband in Detail
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Section A-A
SC Interface Ring
Clampband
2 Mircoswitches
Payload Adapter
Section B-B
φ 1155
Clampband
SC Interface Ring
Payload Adapter
Longitudinal
Restraining
Spring
Pushing Rod
Separation
Spring
Figure B5-6d SC/EPKM Separation Spring
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Section A-A
4
SC/LV Separation Plane
Payload Adapter
2 Microswitches
(Extending Status)
Bracket
φ 1155
SC/LV Separation Plane
Payload Adapter
Pushing Rod
Separation Spring
(Extending Status)
Figure B5-6e SC/EPKM Separation Spring (Extending Status)
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B5.2 LM-2E/EPKM Electrical Interface
The SC is electrically connected with SC's electrical ground support equipment
(EGSE) through SC/LV In-flight-disconnectors (IFDs) and umbilical cables provided
by LV side. In general, SC will control SC/EPKM separation, the SC adapter will
separate from SC together with EPKM. The actual electrical interface between LV
and SC is defined at the interface between LV and EPKM, i.e. the top of the interface
ring. By using of EGSE and the umbilical cables, SC team can perform wired testing
and pre-launch control to the SC, such as SC power-supply, on-board battery charging,
wired-monitoring on powering status and other parameters.
B5.2.1 In-Flight-Disconnectors (IFDs)
z
Quantity
Typically, there are two IFDs symmetrically mounted outside the top ring of the
interface adapter. The detailed location will be coordinated between SC and LV sides
and finally defined in ICD.
z
IFD Supply
Generally, the IFDs are selected and provided by the user. CALT is responsible to
solder IFDs to the umbilical cables. The necessary operation and measurement
description shall also be provided. (If the user selects the China-made connectors,
CALT will provide the halves installed at the SC side.)The available China-made
connectors are YF8-64 (64 pins), FD- 20(20 pins), FD-26(26 pins), FD-50(50 pins),
etc.
z
Separation Signal through IFDs
There are four break-wires on the two IFDs for each SC, which generate EPKM/LV
separation signals. The SC will receive the EPKM/LV separation signals once the
break-wires circuitry break while EPKM/LV separates.
In the same way, there are two break-wires on the IFDs J1 & J2. The IFDs will send
the EPKM/LV separation signal to LV once the break-wires circuitry break while
EPKM/LV separates. This separation signal will be sent to LV’s telemetry system
through EY1 interface. The break-wire’s allowable current: ≤100mA, allowable
voltage: ≤30V.
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B5.2.2 Umbilical System
The umbilical system consists of onboard-LV Parts and ground parts. Refer to Figure
B5-5, Figure B5-6 and Figure B5-7. The 350m-cable from Launch Control Console
(LCC) to Umbilical Tower, EB26/EB36, BOX3, BOX4, and Power-supply 1&2 are
the common to different missions. The onboard-LV cable, as well as ground cable
from WXTC to ED 13,14&15 and BOX1 & BOX2, will be designed for dedicated SC
according to User's needs. In order to assure the quality of the product, the umbilical
system will be provided to the User after pre-delivery acceptance test and
insulation/conductivity checkouts in the launch site.
CS2
CS4
CS1
SAID
CS3
EC4
EC1
EC5
EC2
WXTC
Ground Disarm
Control Box
Figure B5-5 LM-2E/EPKM Electrical Interface
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CS2
CS5A
Onboard-LV
Umbilical Part
CS1
CS4
CS5
EY2
SAID
EC1
EC4
CS3
EY1
WFC2
WFC3
EC2
EY3
EC5
WXTC
ED23
ED24
ED22
Underground
Power Room
8E535-3B
Power
Supply1
36V10A
KSEYVP-6 2 0.75
KYVRP-1 108 0.75
KYVRPP 80 0.5
Ground Umbilical Part
EB26
ED13 ED14 ED15
X1
KYVRP-1 108 0.75
BOX 1
EB37
EB36
BOX3
EB33
EB46
Power
Supply2
36V10A
EB56
X31
BOX 2
P5
ED43
ED44
P6
5m
.1897
5m
.1898
5m
.1899
5m
P7
P1
J1
SC Console
ED42
P8 8E536-3B
P2
J2
P3
J3
BOX4
WK
8E70-3B
WZT
DLWX
P4
J4
SC RPS
Figure B5-6 Umbilical Cable for SC
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B5.2.2.1 Onboard-LV Umbilical Cable
z
Composition
The Onboard-LV cable net comprises the cables from the IFDs (P1, P2) to WXTC.
These umbilical cables will fly with LV.
Whereas:
Code
P1、P2
EC1、EC4
EY1
WXTC
G1
Description
LV/SC electrical connectors at LV side which is
crimp-connected to the cables.
Technological interfaces between SC adapter and LV
Interface between umbilical cable and LV TM system, through
which the EPKM/LV separation signal is sent to LV TM system
Umbilical cable connector (LV-Ground)
Grounding points to overlap the shielding of wires and the shell
of LV
Refer to Figure B5-6.
z
Umbilical Cable Design
SC side shall specify characteristics of the IFDs. The specific contents are pin
assignment, usage, maximum voltage, maximum current, one-way maximum
resistance etc. CALT will design the umbilical cable according to the specified
requirements.
z
Types and performance of Umbilical Cable
Generally, ASTVR and ASTVRP wires are adopted for the onboard-LV cable net:
ASTVR, 0.5mm2, fiber-sheath, PVC insulation;
ASTVRP, 0.5mm2, fiber-sheath, PVC insulation, shielded.
For both cables, their working voltage is ≤500V and DC resistance is 38.0Ω/km
(20°C). The single core or cluster is shielded and sheathed.
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B5.2.2.2 Ground Umbilical Cable Net
z
Composition
The ground umbilical cable net consists of umbilical cable connector (WXTC), cables,
box adapters, etc. Refer to Figure B5-6 and Figure B5-7.
Whereas:
Code
WXTC
BOX1
BOX2
BOX3
BOX4
Issue 1999
Description
WXTC is umbilical cable connector (LV-Ground) whose female half
(socket) is installed at the wall of the VEB, while the male half (pin) is
attached to the top end of ground cable. The disconnection of WXTC is
electrically controlled. (The disconnection is powered by BOX 3 and
controlled by BOX 4. In the mean time, forced disconnection is also used
as a spare separation method.) Generally, WXTC disconnects at about
8min prior to launch. If the launch was terminated after the
disconnection, WXTC could be reconnected within 30min.
The SC should switch over to internal power supply and cut off ground
power supply at 5 minutes prior to WXTC disconnection. Therefore,
during disconnection only a low current monitoring signal (such as 30V,
≤100mA) is permitted to pass through the WXTC.
BOX 1 is a box adapter for umbilical cable that is located inside the SC
Cable Measurement Room on Floor 8.5 of the umbilical tower. (If
needed, BOX 1 can provide more interfaces for the connection with SC
ground equipment.)
BOX 2 is another box adapter for umbilical cable that is located inside
the SC Blockhouse on ground. Other SC ground support equipment
(RPS, Console, etc.) are also located inside the Blockhouse.
This is a relay box for the disconnection of the umbilical cable. BOX 3 is
located inside the under-ground Power-Supply Room. Box 3 is powered
by 2 DC regulated power supply sets. These two power supply sets are in
“working-state” sparing to each other.
BOX 4 is located inside Blockhouse. It is for the control of the pre-launch
disconnection of SC umbilical cables.
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z
Interface on Ground
Generally, there are four interfaces on ground, namely, two for SC Console
(P1/J1&P2/J2), and the other two for SC power supply (P3/J3&P4/J4). SC side will
define the detailed requirement of ground interfaces. Those connectors (P1,P2,P3,P4)
to be connected with SC ground equipment should be provided by SC side to LV side
for the manufacture of cables.
Location
Code
LV side
interfaces
P1
P2
P3
P4
Specification
Quantity
To be defined by SC side
2
2
2
2
If LV side couldn’t get the connectors from SC side, this ground interface cable will
be provided in cores with pin marks.
SC side can also provide this ground cable. The length of this cable is about 5 meters.
If so, LV side will provide the connectors (as Y11P-61) to connect with BOX 2.
z
Type & Performance
The type and performance of the umbilical cables are listed in Figure B5-6.
— Single-Core Shielded Cable
KYVRPP 80×0.5, Copper core, PV insulation, copper film plating on PV for
shielding of each core, PVC sheath, woven wire net for shielding of cable; 80
cores/cable, 0.5mm2/core; Working voltage: ≤60V; DC resistance (20°C) of each core:
38.0Ω/km.
— Ordinary Insulation Cable
KYVRP-1 108×0.75, copper core with PV insulation, PVC sheath, woven wire for
shielding, flexible; 108 cores/cable, 0.75mm2/core; No shielding for each core, woven
tin-plated copper wire for shielding of cable; Working voltage: ≤110V; DC resistance
(20°C) of each core: 28.0Ω/km.
— Twin-twist Shielded Cable
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KSEYVP 6×2×0.75, 6 pairs of twin-twisted cores, 0.75mm2/core. Each twisted pair is
shielded and the whole cable has a woven wire net for shielding. Impedance: 100Ω.
Twin-twist shielded cable (KSEYVP) are generally used for SC data transmission and
communication. Single-core shielded cable (KYVRPP) is often used for common
control and signal indicating. KYVRP-1 cable is adopted for SC’s power supply on
ground and multi-cores are paralleled to meet the SC’s single-loop resistance
requirement.
Under normal condition, the umbilical cable (both on-board and ground) has a
insulation resistance of ≥10MΩ (including between cores, core and shielding, core
and LV shell)
B5.2.3 Umbilical Cable Disconnect Control
LV side is responsible for the pre-launch disconnection of umbilical cable through
BOX3 and BOX 4.
Inside the underground Power Supply Room, there are two 36V/10A DC regulated
power supply which will provide power for the cables. They are all in working
condition sparing to each other.
Generally, according to the count-down launch procedure, only after LV side has
received the confirmation that SC has turned to internal power and SC is normal,
could the order of umbilical cable disconnection be sent out.
B5.2.4 Anti-lightning, Shielding and Grounding
In order to assure the safety of the operations of both LV and SC, some measures have
been taken for anti-lightning, shielding and grounding.
— The cable has two shielding layers, the outer shielding is for anti-lightning while
the inner shielding is for anti-interference.
— For the cables from WXTC to BOX 2, the outer shielding (anti-lightning) has a
grounding point every 20m. These grounding measures can assure the lightning
and other inductance to be discharged immediately. The grounding locations are
either on the swing rods or the cable’s supporting brackets.
— The inner shield has a single grounding. The inner shields of the on-board cables
are connected to BOX 2 through WXTC. BOX 2 has a grounding pole.
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— The inner and outer shields are insulated with each other inside the cables.
B5.2.5 Continuity of SC “Earth-Potential”
The SC should have a reference point of earth-potential and this benchmark should be
near to the EPKM/LV separation plane. Generally, the resistance between all other
metal parts of SC (shell, structures, etc.) and this benchmark should be less than
10mΩ under a current of 10mA.
There is also a reference-point of earth-potential at the bottom of the adapter. The
resistance between LV reference point at the adapter and SC reference should be less
than 10mΩ with a current of 10mA. In order to keep the continuity of earth-potential
and meet this requirement, the bottom of SC to be mated with adapter should not be
treated chemically or treated through any other methodology affecting its electrical
conductivity.
SPECIAL STATEMENT
Any signal possibly dangerous to the flight can not be sent to the SC during the whole
flight till EPKM/LV separation. Only EPKM/LV separation can be used as the initial
reference for all SC operations. After EPKM/LV separation, SC side can control SC
through microswitches and remote commands.
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B5.3 RF Links
B5.3.1 RF Relay Path
XSLC can provide RF link from EGSE to SC either in BS or on the umbilical tower.
Refer to Figure B5-7.
RF
LIN
K
RF
LIN
K
RF
LIN
K
RF
On the Hill
On the
UmbilicalTower
LI
NK
SC T&C RF Field
SC
CS1
CS4
BS2
EGSE
EC2
TO BOX3
J2
P1
P2
WXTC
E C5
40m
BOX1
J1
ED26
ED13 ED14 ED15
X1
ED23 ED24 ED22
BLOCKHOUSE
G1
EY1
LV Telemetry System Interface
SC CONTROL ROOM
350m
SC Console
SC RPS
CLTC is epsonisble for
connection.
J1 P1
P5
J2 P2
P6
J3 P3
P7
J4 P4
P8
X31
BOX2
ED43
ED44
ED42
Underground Umbilical Cables
Figure B5-7 RF Links
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B5.3.2 Characteristics of RF Link
(3) Frequency
C Band:
Ku Band:
Up-link: 5925~6425 MHz
Down-link: 3700~4200 MHz
TBD
(4) Signal Level
C Band: See following table
Ku Band: TBD
Frequency
Telemetry
Command
SC Antenna
EIRP
PFD
37dBm
-85dBW/m2
EGSE
Input
-70dBm
Output
30dBm
SPECIAL STATEMENT
A mission dedicated RF working plan will be worked out. Anyway, the SC RF
equipment should be turned off during the whole flight phase of LV until all SCs are
separated form the LV hardware.
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