Automating Spacecraft Maneuver Planning

1
Automating Spacecraft Maneuver Planning
Execution

• G.K. Johnson1, S.A Hoover,2, A. J. Aparicio,3
•  1Integral Systems, Inc., of Lanham, MD, 20706,
  USA.
• 2Loral Skynet of Bedminster, NJ, 07921, USA
• 3Loral Skynet of Hawley, PA, 18428, USA
• SpaceOps 2004
• Montreal, Canada
• May 17 21, 2004

2
Operational Automations

• New spacecraft are more efficient, powerful and
  operationally capable.
• New designs are also more autonomous on-orbit.
• This has come at the cost of more up-front work
  by operations personnel.
• On some spacecraft, up to 4 maneuvers per day
  required.
• Planning, evaluation execution requires
  automated ground operations to support.

3
Automations Potential

• Process Standardization and Control
• Change process from
• A series of independent actions, that are
• Scheduled independently, and
• Possibly performed differently each time, using
• Data products passed manually from group to
  group, with
• Data held by different groups in many locations
• To a managed, end to end process
• Made up of coordinated, structured process, where
• Actions are scheduled (and visible) centrally,
  that are
• Performed consistently time after time, with
• Products passed from task to task automatically,
  that keeps
• All data readily available and organized to
  provide complete audit trail, allowing the user
  to
• Maintain control over the entire process.

4
Advantages of Automations

• Automations handles repetitive, discrete tasks
  well.
• Most runs do not produce surprises and can be
  sanity checked easily.
• Automated execution ensures repeatability and
  control in process flow.
• Data collection and storage for review, analysis
  and troubleshooting is easily controlled.

5
Scope of Project

• Provide automated control of the following Loral
  Skynet operational tasks.
• Earth Sensor Management Telstar 11
• Maneuver Operations (bi-prop) Telstar 11
• Maneuver Operations (bi-prop SPT) Telstar 8
• Provide for varying degrees of operational
  intervention from full auto to full manual steps
• Provide a system that is capable of expansion to
  new tasks in the operational environment in the
  future.

6
Phase 1 Goals

• Operations Goals
• Provide fully automated control over ESA (Earth
  Sensor Assembly) Inhibit prediction and sensor
  switching command execution and monitoring.
• System Goals
• Prove basic architecture
• Implement inter-process communications
• Develop initial library functions
• Develop user interfaces (auto manual)
• Develop data storage and presentation structure
• Interface to Initial EPOCH IPS modules
• OASYS, Task Initiator ARES

7
Phase 2 Goals

• Operations Goals
• Provide fully automated control over Orbit
  Determination, maneuver planning, execution and
  evaluation for Telstar 11.
• System Goals
• Enhance basic architecture
• Enhance inter-process communications
• Develop extended library functions
• Expand user interfaces for data display and
  evaluation
• Implement data archival options
• Extended interface to EPOCH IPS modules
• ABE archived data retrieval and display

8
Phase 3 Goals

• Operations Goals
• Provide fully automated control for maneuver
  planning, execution (memory operations),
  monitoring and evaluation for SPT thruster
  equipped Telstar 8.
• System Goals
• Expanded constraint checking functionality
• Significant enhancement to sequencing and
  timeline administration
• Expanded library functions
• Extended data archival functions
• Improved data storage and presentation structure
• Interface to EPOCH IPS Memory Management for
  Table loads, dumps and compares

9
Automations Server

• Automations Server executes scripts library
  functions to drive processes.
• Communicates with specialized servers for
  function calls and data access via web server
  architecture.
• Provides GUI interface for tasks and manual
  control options.
• Interfaces with EPOCH Task Initiator to schedule
  real-time, and on-going batch tasks to long term
  operation

10
Specialized Servers

• Specialized servers interact with EPOCH IPS
  modules via cgi (common gateway interface) calls
  to the servers that execute scripts
• Scripts control
• Process requests
• Data access and retrieval
• Status information distribution
• Servers provided for
• OASYS (flight dynamics), ABE (archive data),
  EPOCH (memory management).
• Task initiator interface is TCP/IP socket based.

11
Automations Architecture
12
Automations Core Components
Automation Server
Automation Server holds the scripts that drive
all automation activity. All reports that need
to be reviewed by the user are also stored
here. Task Initiator facilitates full automation
and interaction with ARES.
Automation Tcl Scripts And Dialogs
WEB Server
Task Initiator
Automation Output
Automation Input
The ABE Server provides access to 1. The ABE
batch application. 2. Reports that are generated.
The OASYS Server provides access to 1. The OASYS
batch application. 2. Reports that are
generated. 3. BTD plotting printing service. 4.
HTML printing service.
The EPOCH Server provides access to 1. The
Memory Management application. 2. Reports that
are generated.
13
Maneuver Planning

• High level process flow includes
• Orbit determination
• Track files, OD, constraint checks, propagation
  predicts
• Maneuver Planning (both d/e inclination)
• Planning, constraint checking, command args
  generation, maneuver post process scheduling
• Maneuver Reconstruction
• Data acquisition, recon propagation, predicts
  and constraint checking.
• Maneuver Evaluation
• OD, evaluation database updates, propagation,
  constraint checking, follow on task scheduling
• Timeline, data database updates

14
Typical OD Processing
15
Typical Data Passing
16
Typical Command Processing
17
Process Monitoring

• When run manually, a GUI is provided with each
  step in the procedure presented along with
  status.
• When run automatically (scheduled), all data is
  presented in an HTML based, multi-page, timeline
  based display.
• All entries are hyper-linked and all data (to the
  lowest level procedure call) is available for
  browsing.
• This same view provides for scheduling and
  process control if increased manual intervention
  is desired.

18
Manual Control GUI
\

• Provide status control options to the user.
• Allow user intervention when constraints not
  achieved.
• Provide insight into specific steps of
  automations script processes
• Useful for testing, training and simulation
  actions.

19
Automations Timeline Data
20
Automations Maneuver Data
21
Detailed Data Example
22
Operational Experiences

• Phase 1 and 2 delivered in December 2002.
• Loral Skynet tested Phase 1 ESM (Earth Sensor
  Management) capabilities in parallel with
  heritage prediction system (VAX application)
• Results from ESM matched heritage system
  extremely well established confidence in ESM
• Phase 1 Operational in May 2003
• Phase 2 Still being tested in parallel with
  manual process, expected operational date in
  1Q2004

23
Impact on Operations

• Initial increase in workload during validation
  and testing phases
• Established confidence in automations products
  with parallel operations of heritage systems
• Incorporated automations behind-the-scenes
  (i.e., planning, predictions, analysis, etc.)
  first to minimize impact to real-time operations
• Continue a phased approach to incorporate
  automations with current and future satellite
  operations, Telstar 11 - 1Q04, Telstar 8 - 3Q04,
  and remaining fleet in 2005

24
Automations Expansion

• Automations flow is designed around Projects and
  Sub-Projects
• Projects are usually spacecraft level
• Each major function is a sub-project which is
  part of a project.
• sc1_od the orbit determination sub-project
• sc1_plan the maneuver planning sub-project
• sc1_recon the maneuver reconstruct sub-project
• sc1_eval the maneuver performance evaluation
  sub-project

25
Expansion Techniques

• New projects are added through listing the steps
  to be followed
• These may be custom scripts, or use library
  functions
• They use the simple, open source Tcl/Tk language
• The listing dynamically generates the manual GUI
• Previous projects can be used as templates for
  new items.
• For ease in maintenance, a user may put all
  custom functions in their own Tcl library to be
  called.
• This has been used to add new steps to delivered
  procedures for Loral Skynet in the phase 1
  delivery.

26
Summary

• Loral Skynet and ISI have developed an
  Automations system for spacecraft operations.
• It is installed in the Hawley, Pa. Loral Skynet
  satellite control center.
• It is capable of ESA operations and maneuver
  planning, execution and evaluation for Telstar
  11.
• It is being expanded to support the new SPT
  equipped Telstar 8 spacecraft to be launched in
  2004.
• The system offers an expandable platform for
  automations of many types of modern spacecraft
  operations.