Mission Operations consist of various operational activities necessary to meet science mission objectives. To this end, there are several operations organizations that support ICESat in the areas of telemetry acquisition and commanding, planning and scheduling, data processing and analysis, communications, and orbit determination. Figure 1 shows the mission operations organizations that support the ICESat project to meet mission objectives.

ICESAT MISSION SUPPORT ELEMENTS:

Mission Operations Control (MOC) Center

All ICESat flight operations activities are conducted by the Laboratory for Atmospheric and Space Physics (LASP) in the ICESat Mission Operations Control (IMOC). The IMOC is located in the LASP Space Technology Research building of the University of Colorado in Boulder, Colorado. Flight operations activities include:

• Monitoring the health and safety and commanding of the observatory during realtime operations.
• Post-pass telemetry data acquisition: s-band data playbacks, GPS data
• Mission planning and scheduling
• Command generation
• Engineering data processing and analysis
• Orbit and attitude determination

The IMOC receives telemetry data and sends commands via the NASA Ground Network and from commercial tracking stations contracted by NASA.

Link: Laboratory for Atmospheric and Space Physics

Instrument Support Facility (ISF)

The Instrument Support Facility (ISF) is responsible for the operations of the Geosciences Laser Altimeter System (GLAS) and planning science payload activities, as well as monitoring the health and safety of the instrument. The ISF works closely with flight operations to coordinate all observations, target of opportunities, calibrations and observatory attitude maneuvers.

Investigator-led Processing System (ISIPS)

Science data processing is performed by the Investigator-led Processing System (ISIPS). Science GLAS data will be processed into a variety of data products for archiving and distribution to the scientific community. The processed data will be permanently archived at the National Snow and Ice Data Center (NSIDC) archive system in Boulder Colorado.

EOS Data Operations System (EDOS)

The EOS Data Operations System receives the high-rate data from the polar tracking stations and processes the data to generate Level-0 products. Level-0 processing removes telemetry artifacts from the science data and creates a set of non-overlapping data products for distribution and further processing to the ISIPS and the MOC.

Link: Earth Observing System (EOS) Home Page

Ground Network Tracking Stations

The Ground Network Tracking stations provide X-band capabilities for receiving science data dumps, S-band spacecraft data, real-time telemetry and commanding of the observatory.

The following table summarizes the ground network stations support for ICESat:

Network Support

Communications between ICESat ground system and support elements is provided by networks that are part of the NASA Integrated Services Network (NISN). ICESat will use multiple data network systems to meet mission requirements. These networks include:

• The IP Operations Network (IONet)
• EOS Mission Services Network (EMSn)
• NASA Communications (NASCOM) voice circuits, NASCOM voice communications center at GSFC provides conferencing between any or all parties in support of ICESat testing, launch, and on-orbit operations.

Flight Dynamics Facility (FDF)

The Flight Dynamics Facility provides orbit prediction during launch and early-orbit operations. The FDF generates spacecraft ephemeris information, and sends the information to the IMOC and the tracking stations.

Link: Flight Dynamics Facility

National Snow and Ice Data Center (NSDIC)

The National Snow and Ice Center is located at he University of Colorado in Boulder and is responsible for the archiving and distribution of ICESat science data to the science community at large.

Link: National Snow and Ice Data Center

Science Computing Facility (SCF)

Provides data request and visualization tools to the science team. Distributes data to the science teams.

University Of Texas (UT)

Provides precision orbit and attitude information.

Link: Center for Space Research - University of Texas

International Laser Ranging Service (ILRS)

The ILRS network provides tracking from its global network of laser ranging stations to support the orbit determination activities of the project.

Link: International Laser Ranging Service