This paper will discuss proposed Flight Operations methodologies and technologies for the Earth Observing System (EOS) Operations Center (EOC), to reduce risks associated with the operation of complex multi-instrument spacecraft in a multi-spacecraft environment. The EOC goals are to obtain 100 percent science data capture and maintain 100 percent spacecraft health, for each EOS spacecraft. Operations risks to the spacecraft and data loss due to operator command error, mission degradation due to mis-identification of an anomalous trend in component performance or mis-management of resources, and total mission loss due to improper subsystem configuration or mis-identification of an anomalous condition. This paper discusses automation of routine Flight Operations Team (FOT) responsibilities, Expert systems for real-time non-nominal condition decision support, and Telemetry analysis systems for in-depth playback data analysis and trending

Hudson, Richard K.

Pingitore, Nelson V.

English

NASA Technical Reports Server

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Risk Reduction Methodologies and Technologies for the
Earth Observing System (EOS) Operations Center (EOC)
Richard K. Hudson and Nelson V. Pingitore
Loral AeroSys
1616A McCormick Drive
Landover, Maryland 20785
ABSTRACT
This paper will discuss proposed Flight
Operations methodologies and
technologies for the Earth Observing
System (EOS) Operations Center (EOC),
to reduce risks associated with the
operation of complex multi-instrument
spacecraft in a multi-spacecraft
environment. The EOC goals are to
obtain 100% science data capture and
maintain 100% spacecraft health, for each
EOS spacecraft. Operations risks to the
spacecraft and data loss due to operator
command error, mission degradation due
to mis-identification of an anomalous
trend in component performance or mis-
management of resources, and total
mission loss due to improper subsystem
configuration or mis-identification of an
anomalous condition. This paper
discusses automation of routine Flight
Operations Team (FOT) responsibilities,
Expert systems for real-time non-nominal
condition decision support, and Telemetry
analysis systems for in-depth playback
data analysis and trending.
INTRODUCTION
The Flight Operations Segment (FOS) of
the EOS Core System (ECS) is currently
in early stages of the design process. The
Preliminary Design Review (PDR) is
scheduled for December 1994, and the
concepts discussed in this paper will be
refined as we progress with the
N95- 17612
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development cycle.
The FOS will provide the command and
control system for EOS instruments and
spacecraft. The EOC will be located at
NASA Goddard Space Flight Center
(GSFC) to generate commands to the
instruments and spacecraft of NASA
within the International Earth Observing
System (IEOS) as well as monitoring the
health and performance of these flight
elements.
International partners flying instruments
on NASA EOS spacecraft will be able to
provide these functions for their
instrument from their own center.
Principal Investigators (PIs) and facility
instrument teams will participate in
monitoring their instruments and in
resolving instrument anomalies from their
home institutions through use of an
Instrument Support Terminal (IST)
Toolkit, a special set of software that will
be run on a local computer workstation.
AM-1 will be the first mission to be
supported by the EOC FOT, it is
scheduled for a June 1998 launch. Other
missions currently scheduled to be
supported from the EOC include: AERO-
1 (9/00); PM-1 (12/00); ALT-1 (6/02);
CHEM-1 (12/02), AM-2 (6/03); AERO-2
(9/03); PM-1 (12/05); AERO-3 (9/06);
ALT-2 (6/07); CHEM-2 (12/07); AM-3
(6/08); AERO-4 (9/09); PM-3 (12/I0);
ALT-3 (6/12); AERO-5 (9/12); and
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CHEM-3 (12/12). At full capacity the
EOC FOT will be required to support up
to 7 missions (five on-orbit, one in pre-
launch stage, and one mission in a
"decommissioning" stage).
Systems will be in place well before the
launch of the first EOS satellite to provide
the full functionality required to support
it. The command and control functions
will be brought on-line and fully tested
with simulated EOS data in operational
scenarios.
After the EOS missions are on-orbit and
providing high volumes of data, the EOC
will continue to evolve and add
capabilities in response to new
requirements and lessons learned through
its use. This evolution will be in the form
of planned EOC upgrades. Continued
prototyping will occur, and development
of EOC will be actively sought. This
continuing evolution will enable the EOC
to incorporate advances in data system
technologies, as well as adapt to changing
user requirements.
The FOT shall provide mission operations
support with technical directives from the
NASA Mission Operations Manager
(MOM) and the EOS Project Scientist.
Coordinated mission planning,
scheduling, and commanding operations
shall be performed by the FOT in
accordance with the MOM's policy
guidelines and directives. Instrument
science planning and scheduling
operations, including conflict resolution,
shall be performed under the general high
level direction and guidance of the Project
Scientist. The FOT shall perform
operations necessary at the EOC to ensure
that the ECS FOS achieves the functional
and performance requirement of the ECS
specification. These functions include the
following services: operation planning and
scheduling; command management;
commanding; telemetry processing;
observatory and instrument monitoring
and analysis; data management; element
management; and user interface services.
With increased complexity of space and
ground systems, and interactive science
operations there will be an increase in the
level of complexity of onboard resources
and constraint management. Current tools
for assessing the state of the system
require that FOT members mentally
convert alphanumeric data into a mental
model and reason about the model.
Automated logic checking is performed at
the parameter level, leaving subsytem and
system level assessment as a human task.
Because of this FOT effectiveness is an
issue that promises to grow in the future.
The ECS FOS will supply tools that
reduce FOT sensory requirements. This
will be accomplished through the
development of automated routine FOT
responsibilities. A Decision Support
System, and the EOC Telemetry Analysis
system will be the main tools used to
automate these responsibilities. The goal
of these systems is to aid in complex
parameter checking, and system level
reasoning checks for the FOT. These
tools will also support real-time resource
and constraint management. In the EOC
these tools must effectively manage
multiple payload sets in a dynamic
resource allocation environment.
Automation of expected versus actual
state analysis process will greatly aid the
FOT. FOT productivity gains will also be
achieved by visualization tools for
assessing system status. These
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visualization tools will support graphical
representations of system level data with
the capability of rapidly expanding the
displayed information down to the
parameter level. The promise of improved
visualization techniques is that the FOT
will be able to monitor systems by
exception, rather than through
surveillance• Each of these methods has
the promise of improving FOT
efficiencies and reducing mission critical
risks.
AUTOMATION OF ROUTINE FOT
RESPONSIBILITIES
In traditional control centers significant
labor is expended for routine operations,
such as monitoring subsystem displays,
and supporting poorly engineered
interfaces for the negotiation of external
services (e.g., communications, flight
dynamics). An ECS FOS goal is to
automate and standardize these interfaces.
This will result in increased operational
efficiency, lower system life-cycle costs,
and reduced operational risk.
The FOT will depend heavily on the
accuracy and quality of spacecraft
manufacturer and FOS documentation and
information. Deficiencies in either
spacecraft or FOS documentation or
ground system test results will increase
the level of mission risk, reduced mission
effectiveness, and result in higher life-
cycle costs. These deficiencies will lessen
the FOTs ability to provide accurate
responses to anomalies.
The amount of information required for
operating a spacecraft is staggering. In a
traditional control center this data is stored
on paper in an ad hoc manner. This
information is usually not organized in a
way that allows quick access by the FOT
for real time operations. Frequently this
data is not kept on paper at all, but is
retained in the minds of experienced FOT
members.
We have proposed an extensive on-line
technical information database for the
missions controlled from the EOC. This
system would allow for rapid information
access through keywords, such as:
subsystem name, and telemetry or
command mnemonics. The information
stored within this database will be
integrated to the system level. The
database will also serve as a repository of
system specification, drawings, simulation
and test data, historical data, operations
procedures, and contingency plans.
Traditional control center operations
involve a large number of alphanumeric
displays monitored routinely by subsystem
speclahsts wlth relatively little automatic
checking of data, except for simple limit
checks. The EOC operations concepts for
FOT real-time monitoring calls for most
monitoring to be performed by exception
when specified rules are violated, when
telemetry does not match predictive
models, or when telemetry behavior is
similar to previously known anomalous
patterns.
The EOC telemetry displays will be at a
system level, integrating pictures and
hierarchical diagrams of spacecraft
subsystems with detailed presentation of
subsystem data. Both "idiot lights" and
dense information displays will be
provided and further integrated with
analytic tools that provide data exploration
capabilities.
With the insertion of more powerful
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workstations and operating systems,
complex analytictaskswill be performed
in real time on a non interfering basis.
This will result in lessening the
traditional distinctionbetweenon-line and
off-line systems. As an example,upon
the detectionof a major systemeventor
anomaly, the FOS software might
formulatea list of information relevantto
the problem at hand and automatically
provide pop-up windows displayingand
organizing this information along with
appropriaterecommendations.
EOC DECISION SUPPORT SYSTEM
(DSS)
The EOC FOT will utilize the proposed
DSS to provide long-term analysis support
and reduce mission critical risk factors.
The EOC DSS should encapsulate
knowledge from previous missions.
Spacecraft knowledge is often lost from
mission to mission. In the life of a single
long duration mission key operations
knowledge may be lost due to personnel
attrition. The EOC DSS is envisioned to
disseminate this knowledge across the
missions supported by the EOC.
The FOS DSS will have the following
characteristics:
a. Access to comprehensive detailed
spacecraft and operations knowledge to
provide a systems perspective.
b. A library of extensive tools that are
readily adaptable to a number of problem-
solving activities.
c. A robust pattern-matching capability for
matching experience to new problems.
The DSS will provide the following
functions:
a. Support in-depth spacecraft and ground
system long-term analysis. This will use
the DSS integrated knowledge base
subsystem in a graphical nature.
b. Assist in identifying and resolving
space and ground system problems in a
proactive manner.
c. Assist in developing plans for
correcting current and future problems
through consistent application of domain
knowledge.
EOC TELEMETRY ANALYSIS
SYSTEM
An often neglected, but important aspect
of risk reduction in FOT activities is off-
line analysis. In traditional control centers
this is principally supported through
relatively primitive trending and data
analysis tools. These primarily include
paper listings of trend data that are
analyzed by subsystem engineers to
determine potential degradation of
components.
Careful and continuous analyses of data
can improve the lifetime of a spacecraft
and reduce risks associated with
catastrophic failures. The ECS FOS
software will contain on-line and off-line
support capabilities' tools that provide
rapid analysis of real-time and post-pass
spacecraft behavior, and more direct user
management of spacecraft activities.
Heritage and lessons learned from NASA,
and NOAA missions will be utilized in
developing the EOC Telemetry Analysis
System. Specifically these missions
include Landsat, EP/EUVE, GOES, and
HST.
The EOC Telemetry Analysis System,
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includes increased use of workstation-
oriented interactive data analysis and
visualization tools to support both
spacecraftand subsystemanalysis. It will
scanfor anomalysignaturesderivedfrom
component histories. For example,
changesin batterycharge/dischargeratios
provideearly warningsof batteryfailures.
Such signatureswould be stored in an
operationsknowledge base and used to
predictcomponentfailures.
Proposedspecificsof theEOC Telemetry
AnalysisSysteminclude:
a. Support of automatic searchesfor
interestingdataand couplings: Suchas,
problems caused by couplings between
attitude and power/thermal subsystems.
Unusualiterationswouldbeautomatically
detectedandpresentedfor furtheranalysis
in ourproposedsystem.
b. Comparison to recent trends and
manufacturer's specifications: Sudden
changesin trendsor specificationwould
be immediatelypresentedfor moredetail
analyses.
c. Graphical presentationof knowledge
in discipline-relevant formats: This
includes the presentationof analysesin
understandable formats, overlaid on
spacecraft diagrams or in multi-
dimensional presentation that facilitate
dataunderstandingandexploration.
CONCLUSIONS
The EOS FOT will benefit by having the
proposed FOS architecture and tools.
These benefits include: improved system
performance since FOS is more
responsive to user needs; reduced risk of
spacecraft and/or data loss; lowered
operations costs; reduced time and cost of
supporting new missions by enhancing
the design of the existing ECS FOS
software; reduced operator training time
and providing for retention of experienced
operations personnel knowledge;
increased job satisfaction among FOT
personnel by automating performance of
routine actions; provide for the capability
to insert new technologies/products into
EOC faster; and provide a more
transparent, less obstructive interface
between science users and the instrument
and science data they use.
BIBLIOGRAPHY
Maurice Assaraf, Lessons Learned from the Transportable Payload Operations Control
Center (TPOCC), NASA GSFC SEAS Central Engineering Board presentation, February
17, 1993. Goddard Space Flight Center, Greenbelt, MD.
Allan Jaworski, Gardiner Hall 111, and David Zoch CC2005 An Architecture for Future
Mission Operations Control Centers, Loral AeroSys, Seabrook, MD, October 1992.
Paul Ondrus, and Michael Fatig, Operations Technology Working Group presentation, NASA
Goddard Space Flight Center, Greenbelt, MD, December 1991.
James R. Wertz and Wiley J. Larson (editors), Space Mission Analysis and Design, Kluwer
Academic Publishers, Norwell, MA, 1991.
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Risk reduction methodologies and technologies for the Earth Observing System (EOS) Operations Center (EOC)

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