Science and Mission Control Center for the IMAGE mission*
R. J. Burley, J. L. Green, S. E. Coyle
NASA Goddard Space Flight Center, Greenbelt, MD, USA
*Paper presented at the 2nd International Symposium on Reducing the cost
of Spacecraft Ground Systems and Operations, Oxford, UK, July 21-23, 1997.
The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE)
mission is the first NASA mission in a series of mid-sized explorers
(MIDEX). All seven of the IMAGE instruments will be used to study the
global response of the magnetosphere to changes in the solar wind in new
and unique ways. The mission will utilize neutral atom, ultraviolet, and
radio imaging techniques. IMAGE is currently planned for launch in January
In order to drive the design of new spacecraft and ground systems
towards lower operations costs, the MIDEX flight series required a fixed
mission operations and data analysis (MO&DA) budget for the life of the
mission. The total MO&DA budget for IMAGE is not to exceed $15 million US
dollars. This fixed budget has provided the impetus to re-examine, and to
change, the existing mission operations paradigm at the Goddard Space
Flight Center (GSFC).
To keep within the cost cap of operating the IMAGE mission for three
years the IMAGE project is pioneering a new mission and science operations
concept for NASA. This concept involves a number of important elements such
- The consolidation of the traditionally separated science and mission
operations centers into a single facility called the SMOC (Science and
Mission Operations Center). The SMOC approach also has the desired effects
of consolidating the operations staff and of minimizing the number of
interfaces within the system.
- The consolidation of personnel from across Goddard into a single combined
development team. This activity is both preceding, and to some extent
driving, the current restructuring of the Goddard Space Flight Center.
- Adoption of industry standards for all data communication.
- Reducing the size of the Spacecraft Control Team, through increased use
of expert systems for spacecraft and instrument health and safety
monitoring. The expert system will use a C-Language Integrated Production
System (CLIPS) rules base to monitor spacecraft and instrument health and
safety telemetry as it is received in the SMOC, and will page the on-call
member(s) of the operations staff when a hazardous condition has been
detected, or if the telemetry has not been received when expected.
- Implement a base line design for the ground system that is for unattended
operation. Previously at Goddard, the design of the ground system has
usually been driven by LEOP (Launch and Early Orbit Phase) requirements,
instead of autonomous nominal operations.
- Selection of a telemetry processing and commanding system that can
fulfill both mission operations and payload integration and test phase
functions, eliminating the necessity to translate and re-test the project
database between mission development phases.
- Integration of Level-Zero and Level-One science data processing into a
single automated data pipeline. This includes the automated initiation of
science data processing after a pass has been completed and automated
forwarding of all products to a publicly accessible web-server for
immediate availability and distribution.
- Adoption of a public domain data standard for Level One data products,
for which a wide suite of support software already exists. This standard
is the Common Data Format (CDF), and is the standard used for the
International Solar-Terrestrial Physics (ISTP) Key Parameters.
- The data policy of the mission is that all data is immediately available
to the public. No proprietary data rights or periods exist for the
mission. This policy eliminates any requirements for the intermediate
archiving of any data products. All products will be immediately forwarded
to the National Space Science Data Center (NSSDC), the ultimate repository
for the data, for immediate distribution.
- Spacecraft design has large power, thermal, and data budget margins,
making the spacecraft itself more robust and autonomous.
As implemented by the IMAGE project, the move away from the
traditional ground systems developed at GSFC will both greatly reduce
operations costs, and, greatly reduce development costs for the IMAGE
mission and for other spacecraft in the MIDEX mission series.
The Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) mission
is the first of the new MIDEX series of
medium-class explorer spacecraft. The overall objective of IMAGE is to
determine how the magnetosphere responds globally to the changing
conditions in the solar wind. Specific questions to be addressed include
(1) what are the dominant mechanisms for injecting plasma into the
magnetosphere on substorm and magnetic storm time scales? (2) what is the
directly driven response of the magnetosphere to solar wind changes? and
(3) how and where are magnetospheric plasmas energized, transported, and
subsequently lost during storms and substorms? The IMAGE mission will use
four imaging techniques to address these questions: neutral atom imaging
(NAI) over an energy range from 10 eV to 200 keV, far ultraviolet imaging
(FUV) at 121 - 180 nm, extreme ultraviolet imaging (EUV) at 30.4 nm, and
radio plasma imaging (RPI).
In order to drive the design of new spacecraft and ground systems towards
lower operations costs, the MIDEX flight series required a fixed mission
operations and data analysis (MO&DA) budget for the life of the mission.
The total MO&DA budget for IMAGE is not to exceed $15 million US dollars.
This fixed budget for IMAGE, indeed with declining MO&DA budgets for all
NASA missions, life cycle cost reductions have become a major driver in
Goddard Space Flight Center (GSFC) development and orbital operations
tasks, and has provided the impetus to re-examine, and to change, the
existing mission operations paradigm at GSFC.
2.0 The Past
Since the earliest missions at the Goddard Space Flight Center, the design,
development and operation of the ground systems have all been based on a
facilities-oriented design. All mission functions including; mission
control, spacecraft control, payload control, orbit determination and
control, attitude determination, calibration and control, mission planning,
and science data processing and distribution, all were performed in
separate facilities, on separate hardware, and developed by separate teams.
These facilities often had redundant functionality. Different mission
phases, including component development, integration and test, and on-orbit
operations, were usually done by different teams, from different
organizations, using different systems. Each of these different facilities
or teams created or reused it's own hardware, software, development
process, development and operations staff, review processes, database and
documentation. This resulted in inefficient transitions between spacecraft
development phases, repeated work, and a fragmented product. The most
severe fragmentation occurred between I&T and on-orbit operations. Work
and knowledge were nearly completely duplicated as the spacecraft
transitioned from I&T to on-orbit operations at launch.
Then, as mission budgets tightened, end-to-end system engineering was
substituted with the mandate to reuse as much as possible from previous
missions, even if this reuse included now-obsolete systems and/or processes
and infrastructure. Significant reinvestment into new systems and new
mission implementation processes were superseded by the budget-imposed
requirement to minimize system change. What development did still occur,
was optimized to minimize development costs. Because MO&DA costs were
mostly funded from a different source, operations efficiency was rarely a
What resulted was a complex infrastructure of entrenched, expensive
multi-mission facilities and systems, which although they were adaptable to
new missions, they were expensive to operate and maintain, and ill-prepared
for the changing times.
The preceding diagram shows the interfaces and the number of facilities
involved in the day to day data flow within the SOHO ground data system.
The following table shows the current system manpower staffing required to
support the GSFC elements of the ISTP ground data systems:
||FY 97 Staffing
|Flight Dynamics Facility
|Flight Operations Teams
|Science Planning & Operations Facility
|Experiment Operations Facility
|Data Processing Centers
||Central Data Handling Facility
||Data Distribution Facility
||Packet Processor Facility
||Data Capture Facility
|Management (includes QA, admin,
configuration control and test teams)
Note: these are "ballpark" figures. Re-engineering efforts are currently
underway to reduce ISTP operations costs by 70% to enable the extended ISTP
mission phase thru 2001 without compromising scientific goals.
As mission budgets have shrunk even further, it is obvious that it has
become impossible to sustain this level of infrastructure any longer. New
ground system designs and development and operations concepts are needed.
3.0 Lessons Learned
Despite the undisputed technical success of mission operations at GSFC,
MO&DA costs were correctly judged to be too high. A series of technical
reviews and papers focusing on the impact of missions operations on life
cycle costs, identified several key ground system design features or
practices that adversely affected the mission operations life cycle cost.
Among the many NASA-level recommendations made by the "Mission Operations
Evaluation Team Report for Space Physics Mission Operations and Data
Analysis" report to NASA HQ on February 27, 1995, by Gael Squibb1 were:
- Establishment of accounting mechanisms that provide unambiguous
total costs for each project, life cycle budget responsibility and
establishing an MO&DA cost cap.
- Elimination of unnecessary redundancy and duplication of effort
among the many facilities involved in MO&DA by the consolidation of mission
- Establishment and utilization of a Space Physics Data Standard,
and elimination of redundant data archive facilities by adoption of an open
Research into the life-cycle costs of science data archiving is documented
in the paper "A Comprehensive Cost Model for NASA Data Archiving"2 by Dr.
James Green of the National Space Science Data Center which analyses the
factors which affect data archiving costs. Among the many evaluations made
by this paper were:
- Development of a PDMP (Project Data Management Plan) is a
critical activity as a pre-mission activity. It should include all data
format descriptions so that the required system development can proceed,
and identify planned inventory and other metadata required to navigate the
- Interdependency within the number of distinct data products is
chiefly reflected in the software development and maintenance costs.
- The effect of data standards on the impact of archive and
- The effect of data granularity on the impact of archive and
The design of the new IMAGE ground data system is predicated on these
observations, and on the direct experience of a diverse group of systems
developers from across the Goddard Space Flight Center, including members
of the Mission Operations Directorate, the Engineering Directorate, and the
4.0 The Present
The IMAGE ground data system is pioneering a new ground system design and
operations concepts at the Goddard Space Flight Center. The fundamental
characteristic of it's design is the consolidation of all missions
operations and science operations into a single operations facility called
the SMOC (Science and Missions Operations Center). The consolidation of
facilities also allows us to consolidate the system development team, and
minimize it's size. It allows us to consolidate mission operations into a
single facility, which minimizes the size of the operations staff required
to operate and maintain the system. This co-location and consolidation
fosters the communication between the subsystem developers which is
critical to mission success, and eliminates a layer of management that
existed in previous, facilities-oriented designs. This activity is both
preceding, and to some extent driving, the current restructuring of the
Goddard Space Flight Center. Consolidation has additional benefits. This
consolidation, and adoption of industry standards for all data
communications minimizes the number of interfaces within the system, which
reduces both development and system validation efforts, which also
facilitates the automation of the system.
The IMAGE ground system team has been given the opportunity to reengineer
the spacecraft and ground system development process as well by creating a
single ground system solution to support all mission phases including
component development, integration and test (I&T), launch site operations,
and on-orbit spacecraft and instrument operations. The ground system,
project database, page displays and procedures are developed in conjunction
with each stage of spacecraft development. Substantial cost savings accrue
with the elimination of multiple ground system development efforts,
elimination of transitions between spacecraft development phases and all
its requisite product generation. Knowledge retention is maximized is
achieved by involving the Spacecraft Control Team (SCT) in all aspects of
the IMAGE project from spacecraft and payload development through on-orbit
The IMAGE ground system is being implemented with a design that is
baselined for unattended on-orbit operations. This is possible because the
spacecraft and payload itself is designed to be operated in a
low-maintenance manner, with a self-safing spacecraft and payload, and
adequate power, thermal and data margins. Lights-out operations is the
norm for the mission, with nominal activity planning, trend analysis and
anomaly resolution being the primary manual efforts. Further reductions in
the size of the SCT is being achieved through the use of an expert system
for spacecraft and instrument health and safety monitoring. The expert
system will use a C-Language Integrated Production System (CLIPS) rules
base to monitor spacecraft and instrument health and safety telemetry as it
is received in the SMOC, and will page the on-call member(s) of the
operations staff if and when a hazardous condition has been detected, or if
the telemetry has not been received when expected.
The generation of over 40 Level-Zero and Level-One science data products
per day will be integrated into a single automated data pipeline. This
includes the automated initiation of science data processing after a pass
has been completed, and automatic forwarding of all data products to a
publicly accessible web-server for immediate availability and distribution.
The science return generated by the IMAGE mission is being maximized by the
adoption of a public domain data standard for which a wide variety of data
already exists, and for which a suite of support software already exists.
This standard is the Common Data Format (CDF), which is a portable,
self-documenting, self-describing data format developed and maintained by
the National Space Science Data Center (NSSDC) at GSFC. Although it was
originally defined as a science data format, it is equally applicable as an
engineering data standard and is being utilized for trend analysis
functions, and for orbit and attitude history functions.
Projected spacecraft control team staffing:
The data policy of the IMAGE mission is that all data is immediately
available to the public. No proprietary data rights or periods exist for
the mission. This policy eliminates any requirements for the intermediate
archiving of any data products. All Level-Zero and Level-One data products
produced in the SMOC will be immediately forwarded to the National Space
Science Data Center (NSSDC), the ultimate repository for the data, for
permanent archive and for immediate distribution.
All of the subsystems in the SMOC have already been developed at Goddard in
one organization or another, and been successfully operated in one facility
or another. The IMAGE ground system is the first time that they all will
be integrated together into a single mission operations system. These
* Front End Data Server (FEDS). Currently being ported from an expensive
VME equipment rack to a single Dec Alpha, this system receives, logs, and
records CCSDS telemetry frames as they arrive over an IP network connection
in the case of normal mission operations, or from an RS422 serial card in
the case of spacecraft I&T phases. It performs frame-sync and Reed-Solomon
decoding functions in software. It decommutates CCSDS source packets from
the telemetry frames, and forwards the packets to any requesting process
over a unix socket connection. It also performs all post-pass Level-Zero
* Advanced Spacecraft Integration and System Test (ASIST). Provides real
time command and control for spacecraft and payload control system
applications. It is language driven with a distributed system capability
and can be configured for a variety of applications and payload
characteristics. It features advanced graphical and textual display
capabilities, a STOL language driven decommutation application, integrated
history archives, and extensive data export capabilities.
* Command Management System (CMS). Constructs, calculates, or ingests,
spacecraft and payload command sequences, and antennae schedules and
validates them. Handles both absolute and relative time sequences.
Manages spacecraft on-board tables and memory loads.
* Generic Spacecraft Analysts Assistant (GENSAA). Uses a CLIPS rules base
to monitor spacecraft and payload health and safety parameters, and SMOC
* Multi-Mission Single Axis Satellite System (MSASS). Recently converted
to a MATLAB application, this system performs the routine validation of the
OBC-derived attitude by receiving attitude sensor data, computing the
spacecraft attitude, and comparing this to the OBC-derived attitude
received in telemetry.
* Coordinated Data Analysis Website (CDAWeb). Uses a set of PERL programs
to generate Common Gateway Interface (CGI) pages for a world-wide-web
interface by examining it's science inventory database, and for
automatically code-generating IDL (Interactive Data Language) programs to
read and display data contained in CDF files. (See associated web pages:
5.0 Summary - "Better - Faster - Cheaper"
The IMAGE ground data system, and it's companion MIDEX mission the
Microwave Anisotropy Platform (MAP), are pioneering both new ground system
designs and new mission development strategies at the Goddard Space Flight
Center which will significantly lower both mission development and mission
operations life cycle costs. Current budget projections indicate that the
ground systems for these missions will cost between one-tenth to
one-twentieth the cost of the ground systems for previous, similar,
missions done by the GSFC. They will require only minimal operations staff
support after launch and early orbit checkout due to consolidation of its
facilities and staff, automation of routine functions, and because of a
low-maintainence spacecraft and mission design.
Mr. Richard Burley is the Ground System Manager for the Imager for
Magnetopause to Auroral Global Exploration (IMAGE) mission, which is being
done at the NASA/Goddard Space Flight Center. His mission experience
includes: Data capture, logging and playback system for the GSFC
Trajectory Computations and Orbital Products Systems, Real-time
magnetometer bias determination for GRO, Pitchback attitude maneuver
commanding for COBE, Star Identification and fine attitude determination
for UARS and EUVE, Telemetry simulation for WIND and POLAR, Telemetry
processor for SAMPEX, was a member of the Common Data Format (CDF) team
which won runner-up for NASA software of the year in 1995, is the primary
developer of the Coordinated Data Analysis Web system (CDAWeb), and has
been the author or co-author on four papers presented to the American
1 Green, J. L., Klenk, K. F. and Treinish, L. A, A Comprehensive Model
for Data Archiving, available from NSSDC/GSFC, Greenbelt, Maryland,
2 Squibb, G. F., et.al., Mission Operations Evaluation Team Report for
Space Physics MO&DA, available from NSSDC/GSFC, Greenbelt, Maryland,
February 27, 1995
Dr. D. R. Williams, email@example.com, (301) 286-1258
NSSDC, Mail Code 633, NASA/Goddard Space Flight Center, Greenbelt, MD 20771
NASA Approval: J. L. Green, firstname.lastname@example.org
Last Revised: 13 April 1998, DRW