Katsuyoshi Arai, Shigeru Usuki, Hidemi Hase, Hiroyuki Miyamoto, Satoshi Fukumoto

1
ADEOS-II TTC operation with space network system

• Katsuyoshi Arai, Shigeru Usuki, Hidemi Hase,
  Hiroyuki Miyamoto, Satoshi Fukumoto
• Japan Aerospace Exploration Agency (JAXA)

2
Contents

• 1) Introduction
• 2) Overview
• 3) Tracking and Control system
• 4) Advantage of using SN
• 5) Problem and Solution
• 6) conclusion

3
Introduction (1/2)

• ADvanced Earth Observing Satellite-II (ADEOS-II)
  , the successor to ADEOS, has been developed to
  advance Earth observation technologies.
• It acquires data to help researchers understand
  the mechanism of the global environmental changes
  such as global warming and to support meteorology
  and fishery activities.

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Introduction (2/2)

• The scientific goals of ADEOS-II can be
  summarized as follows.
• Regularly monitor the water and energy cycle as a
  part of the global climate system.
• Quantitatively estimate the biomass and
  fundamental productivity as a part of the carbon
  cycle, which plays an important role in global
  warming.
• Detect trends in long term climate change as a
  result of continuing the observations started by
  ADEOS.

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Overview of ADEOS-II(1/7)

• Dimension
• Main body Approx. 644m (X-axis Y-axis
  Z-axis)
• Solar Array Paddle Approx. 324m
• Mass 3.68t
• Power 5,350W (EOL)
• Orbit
• Altitude 802.92km
• Period 101 minutes
• Recurrent Period 4 days

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Overview of ADEOS-II(2/7)
Fig.1 View of ADEOS-II
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Overview of ADEOS-II(3/7)

• ltCritical phasegt
• 14 Dec 2002 Launch (at 103100) From
  Tanegashima Space Center by H-IIA4.
• 17 Dec 2002 AOCS Normal Mode Transition
  completed

AOCS Normal Mode is normal attitude control mode
using gyros.
Fig.2 Launch of ADEOS-II from Tanegashima Space
Center
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Overview of ADEOS-II(4/7)

• ltInitial Orbit Controlgt
• 20 Dec 2002 Test maneuver (1N, 20N)
• 23 Dec 2002 Delta i (20N)
• 29 Dec to 10 Jan Delta a 1 to 5 (1N)

DRTS
ARTEMIS
ADEOS-II
Fig.3 ADEOS-II footprint
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Overview of ADEOS-II(5/7)

• ltInitial checkout phasegt
• 18 Jan 2003 AMSR first image acquired.
• 25 Jan 2003 GLI first image acquired.
• 19 Feb 2003 Inter Orbit Communication succeeded
  (via DRTS Space Network).
• 19 22 Mar 2003 System overall test (part 1)
• 25 27 Mar 2003 ADEOS-II ARTEMIS checkout
• 2 9 Apr 2003 System overall test (part 2)

Fig.4 first image (left AMSR, right GLI)
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Overview of ADEOS-II(6/7)

• 15 Apr 2003 Routine Operation started.
• The routine operation of ADEOS-II started on 15
  Apr 2003, using DRTS Space Network for main link
  of ADEOS-II TTC operation and Mission data
  acquisition.

Fig.5 ADEOS-II image on orbit
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Overview of ADEOS-II(7/7)

• Master schedule

Table 1 ADEOS-? Tracking and Control System
2003
2002
Apr.
Mar.
Dec.
Jan.
Feb.
Tracking and Control Team
Check-out Phase
Initial Check-out Phase Completion Review
(NASDA) 4/14
?

12/14 Launch
Initial Critical Phase( 12/17)
1/10
Critical Phase
Initial Check-out Phase
Check-out
Routine Operation (Cal.Val)
Bus Equipment
EPS/AOCS etc.
12/15
4/9
EPS/AOCS etc.
2/17
3/10
3/27
3/29
2/21
2/27
IOCS



IOCS(DRTS)
IOCS(ARTEMIS)
Mission Equipment
2/23
1/21
ETO operation
2/26
1/20
System Total
3/19
3/22
System Total 1
4/2
4/9
System Total 2
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Tracking and Control system (1/3)

• ADEOS-II has two communication ways for TTC
  operation.
• Ground Network system (GN)
• direct communication between ground station and
  ADEOS-II see Fig.6
• Space Network system (SN)
• communication via data relay satellite with
  Inter- Orbital Communication Subsystem (IOCS)
  onboard ADEOS-II see Fig.7

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Tracking and Control system (2/3)

• Ground Network System

USB (CMD,TLM,RNG)
Ground Network Line
ADEOS-II
TSUKUBA Space Center (TACC)
OKINAWA (OTCS)
MASUDA (MTCS)
KATSUURA (KTCS)
Foreogn station
Fig.6 Ground Network system
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Tracking and Control system (3/3)

• Space Network System

DRTS
ARTEMIS
ADEOS-II
Feeder link
Feeder link
ESA
Tsukuba Space Center (TACC)
PGT
HGT
Redu Station
TLM, CMD, RNG data
TLM, CMD data
Fig.7 Space Network system
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Advantage of utilization of SN (1/4)

• After initial checkout phase, ADEOS-II has used
  SN. The advantages of utilization of SN are
  below.
• Longer operation time and more passes
• Global data and high resolution data
• Sending more commands per a pass
• Planning Operation easier
• Finding troubles earlier

Ground Station
DRTS
ADEOS-II
Fig.8 ADEOS-II Space Network system via DRTS
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Advantage of utilization of SN (2/4)

• Visibility with GN (TACS KRN station)

KRN
KTCS
MTCS
OTCS
Fig.9 Space Network system
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Advantage of utilization of SN (3/4)

• Geometrical visibility with SN via DRTS

DRTS
Fig.10 Space Network system
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Advantage of utilization of SN (4/4)

• Daily operation plan (nominal pattern)
• GN visible pattern (TACS KRN station)
• SN visible pattern (via DRTS Kodama)

GN Pass
SN Pass
00
06
12
18
24
00
06
12
18
24
TACS is JAXAs ground stations in Japan. KRN
station is also JAXAs one in Kiruna, Sweden.
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Lesson and Learned (1/2)

• Concernings as a SN user is below.
• Interruption by heavy rain
• The only data relay satellite, DRTS
• Coordination of GN assignment in case of SN
  service stopping
• Increasing the SN user satellites in the near
  future

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Lesson and Learned (2/2)

• Solution for the concernings
• When forecast of be heavy rain (i.e. typhoon,
  rainy season) occurs, ADEOS-II changes TTC
  operation from SN to GN operation boforehand.
• The establishment of command sequence for the
  disturbance of SN service in order to change from
  old plan to new plan
• The establishment of operation re-planning
  sequence

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Conclusion (1/2)

• 1. Space network(SN) system is very useful for
  the satellites which get global data, like
  ADEOS-II.
• Longer operation time and more passes
• Semi-real time data acquisition
• 2. But SN is one of the network systems, which
  consists of data relay satellite and ground
  network.
• 3. When SN service stops, the user satellite
  requires GN resource in order to keep user
  satellite operation.

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Conclusion (2/2)

• 4. The more SN user increases, the harder it
  keeps GN resource because data relay satelite is
  only DRTS.