Third Generation Spacecraft Management and Control System SMACS and Future Conception

1
Third Generation Spacecraft Management and
Control System (SMACS) and Future Conception

• Katsuyoshi Yamamoto, Yusuke Murata, Takashi Asama
  
• and Norikazu Kawahara
• SORUN Corporation, Minato-ku, Tokyo, 108-8368,
  JAPAN
• Hiroyuki Itoh and Makoto Kawai
• Japan Aerospace Exploration Agency, Tsukuba-shi,
  Ibaragi, 305-8505, JAPAN

SpaceOps 2006 _at_Italy/Rome
21 Jun 2006
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Contents

• 1. Introduction
• 2. Outline of the third generation spacecraft
  control system
• 3. Automatization of the spacecraft control
• 4. Basic concept for automatization
• A. Operational condition (OCD)
• B. Operational data (ODT)
• 5. Future conception
• 6. Conclusion

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1. Introduction

• Currently artificial spacecrafts are becoming
  larger or smaller depending on the mission
  request and have become more diversified than
  ever.
• In consideration of these circumstances,
  improvement in reliability and reduction in both
  maintenance and operation costs are being sought
  for the spacecraft control system.
• In this thesis, the automatization of the third
  generation spacecraft control system is discussed
  with regards to improvement in reliability and
  reduction of costs.
• As the means to do so, automatized operation
  using the Spacecraft Operations Procedure (SOP),
  that collects information regarding spacecraft
  operation, is proposed and for its realization,
  an abstract concept of the control operation is
  discussed. Lastly future concepts of the
  spacecraft control system are described.

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2. Outline of the third generation spacecraft
control system

• The third generation spacecraft management and
  control system (SMACS) was developed through the
  accumulated know-how from past spacecraft
  management and control systems and provides
  following major features
• A. Database compilation with accurate spacecraft
  information
• Provision a database of accumulated spacecraft
  information from check-out to the control system.
• B. Flexibility in computer architecture as well
  as additional new
• functions in the future
• SMACS is implemented in JAVA language. Also a
  distributed object-oriented design is adopted for
  the architecture, so this implementation enables
  distributed processing by multiple computers
  depending on the amount of spacecraft data
  processing.
• Software is developed as modules, so its
  structure is easier to modify by changing the
  modules according to future spacecraft demand.

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2. Outline of the third generation spacecraft
control system

• C. Operational improvement
• For real-time spacecraft operation control in
  SMACS, an operational procedure according to the
  computerized Spacecraft Operations Procedure
  (SOP) based on XML is adopted, which will be
  explained later in chapter 3, and planned
  operation can be continuously carried out.
• Also for planning and evaluative analysis, a
  function was also established, where the system
  can automatically conduct a planned operation
  instead of operator processing by advance entry
  of the execution time.
• This could be realized by the basic concept of
  the system operation data described in chapter 4.
• D. Extended service for the spacecraft user
• For recent spacecrafts, AOS, as recommended by
  CCSDS, and space packet transfer with
  tele-command have been mainly used in space link
  protocol.
• SMACS has a database for telemetry commands
  regarding the space packet unit in its structure
  and executes processing according to this space
  packet unit.
• This system can be applied for all kinds of
  telemetry command processing systems using space
  packets.

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3. Automatization of the spacecraft control

• The following improvements were implemented for
  SMACS.
• 1) Automatic confirmation, which was previously
  conducted by an
• operator, can be performed by SMACS.
• 2) Automatic recording of operation results can
  be performed by SMACS.
• 3) All information is displayed on the control
  screen so transmission and
• confirmation results can be realized at a
  glance.
• 4) The concepts of operational condition (OCD)
  and operational data
• (ODT) make SMACS possible to describe
  control and confirmation of
• GN and SN within SOP.
• 5) Control and confirmation of GN and SN
  described in SOP are available
• in SMACS automatically.

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3. Automatization of the spacecraft control

• When the above requests are realized, the display
  screen of SMACS will show SOP as is and implement
  1 step as a basic run unit.
• Figure 1 shows execution flow within 1 step and
  is explained below.
• 1) Start conditions for the Evaluation
• 2) Execution of operation data
• 3) Evaluation of confirmation items
• 4) Judgment for recovery action
• 5) Operation by recovery SOP
• In addition, the system has also following
  features for the automatization.
• a) Sub SOP, consisting of a telemetry check and
  transmission of multiple
• commands, can be called up from the main
  SOP.
• b) Steps for execution can be selected according
  to the status of both the spacecraft
• and the earth.

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3. Automatization of the spacecraft control
Start
1)

Evaluation of start condition
Judgment of start condition
False
Not finished
Within window width
True
Judgment of items
Finished
3)
2)
Evaluate confirmation items
Conduct operation data
Checked for each update
Judgment of result
Judgment of result
NG
NG
OK
OK
Within window width
All conducted
Not finished
Not finished
Finished
Finished
4)
Evaluation of abnormal condition
Judgment for recovery action
False/ not defined
True
5)
Normal termination
Stop automatized operation Move to recovery SOP
Stop automatized operation
To the next step
Figure.1 Execution flow of operational
procedure for 1 step
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4. Basic concept for automatization

• In the SMACS, status data was abstracted as a
  modeled object in the form of operational status,
  and control data was abstracted as modeled object
  in the form of operational data as described
  below.
• A. Operational condition (OCD) status
  data
• B. Operational data (ODT) control data
• SMACS successfully realized a simplified software
  structure.

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4. Basic concept for automatization

• Operational condition (OCD)
• Operational condition is a model to apply
  an abstracted spacecraft monitor model to the
  expression of equipment and system status located
  on the earth. Therefore total monitor, including
  equipment on the earth, can be realized with
  this.
• Figure 2 shows this model. In the model,
  data is processed in the following order.
• 1) SMACS receives the collected status data.
• 2) Raw data for each status date is
  extracted from the received data.
• 3) The extracted data is then converted to a
  physical quantity.
• 4) Converted data is evaluated as to whether
  it is an expected value.

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4. Basic concept for automatization
A. Operational condition (OCD)
Generating information
System to be observed
2)
Extraction of condition of each equipment
1)
4)
3)
Conversion to physical quantity
Evaluation of physical quantity
- Spacecraft - Outside system - Internal system
Status data
Receiving
Operational condition
Physical quantity
Evaluation result
Product
Operational condition
Raw data
Operational condition
Figure 2 Conceptual model for operational
condition
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4. Basic concept for automatization

• Operational condition (OCD)
• SMACS has the operational condition as shown in
  Table 1. This operational condition is generated,
  when telemetry data is received from a spacecraft
  or status data is input from an external system.
  It is also generated, when an operator gives
  directions to the system.
• The generated data contains raw data and
  converted data as shown in Table 2.
• Generated OCD is used for automatized
  confirmation according to SOP and also used by an
  operator to confirm operational condition.

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4. Basic concept for automatization
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4. Basic concept for automatization
A. Operational condition (OCD)
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4. Basic concept for automatization

• B. Operational data (ODT)
• Operational data is a modeled object, where
  data and process of the control equipment in the
  spacecraft and the earth station for objective
  status is modeled by an control model abstraction
  of the spacecraft.
• The model is shown in Figure 3 In the
  model, data is processed in following order.
• 1) A check is conducted before transmission
  according to the execution
• directions from the operator.
• 2) If the check before transmission is OK,
  then transmission data is generated
• and transmitted to the control target.
• 3) Response from the control target or
  control result from the received data is
• confirmed.
• 4) Result of confirmation is then
  communicated to the operator.

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4. Basic concept for automatization
B. Operational data (ODT)

• Figure.3 Conceptual model of operational data
• SMACS contains the operational data as shown
  in Table 3.
• Control of spacecraft equipment and earth
  facilities such as IOL antenna control of the
  spacecraft, changing the link configuration in
  SN, etc., can be realized within a single SOP by
  using these operational data.

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4. Basic concept for automatization

• B. Operational data (ODT)

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5. Future conception

• The third generation spacecraft control system
  acquired a software development platform
  independent of the computer architecture in order
  to handle changes in the computer environment.
  This has led to higher reusability of software.
  In addition, by using modules, the system is
  easier to update according to future demand, so
  development can be conducted in a timely manner.
  Under these circumstances, the timely development
  according to changes in future space exploitation
  can be selected rather than a revision each
  decade.
• For such a timely course of development, the
  following 3 concepts are shown
• A. To establish system by compiling a knowledge
  database of operational condition as well as
  command sequences within planned operations,
  enabling the reduction of development costs and a
  flexible correspondence to the design changes in
  spacecrafts and changes in operation methods.
• B. To establish a system for the optimized
  distribution planning of user demands by
  utilizing multiple spacecrafts as well as a
  coordinated integrated observation system, to
  handle future series spacecrafts.
• C. To establish a lighter spacecraft control
  system targeting small-sized spacecrafts as well
  as a framework specified for geostationary
  spacecrafts, orbiting spacecrafts and earth
  observing spacecrafts.

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6. Conclusion

• SMACS is a system where a model is constructed
  from the operation analysis to control
  spacecraft operation, that incorporates all
  know-how until now, to accommodate the future.
• SMACS is now supporting the ALOS operation which
  was launched in January, 2006.
• The ability of SMACS is evaluated that it met the
  surrounding expectations. But some points to be
  improved are confirmed. By repeated actual
  operations, evaluations, and improvements, as
  well as by advances in software reusability and
  reliability, we strive to develop a more advanced
  system that is user-friendly.