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Hubble Facts
National Aeronautics and Space Administration
FS-97(01)-001-GSFC
The focal point of all Hubble Space Telescope (HST) activities
is the Space Telescope Operations Control Center (STOCC) at NASA's
Goddard Space Flight Center in Greenbelt, Md., where the orbiting
observatory is managed.
The STOCC truly is the nerve center for Hubble - all commands to the space telescope are issued from the facility, and data gathered by the observatory arrive there first. The STOCC consists of six facilities: Mission Operations Room, Servicing Mission Operations Room, System Engineering and Evaluation Room, Payload Operations Control Center, Mission Support Room and Engineering Support System. A description of each facility comprises the rest of this fact sheet.
Mission Operations Room (MOR): The MOR is used to control and monitor HST flight operations, engineering and science activities. It contains the operational work stations and displays required to monitor the health and safety of the spacecraft. It also provides the system capability to command the spacecraft and monitor all engineering and science activities. Adjacent to the MOR is another room called the Servicing Mission Operations Room (SMOR), which is used to support the preparation, test and simulation for the HST Servicing Mission while routine operations are conducted simultaneously at the MOR. The SMOR has the same capabilities as the MOR and can quickly be configured to support routine operations or any other Hubble spacecraft support activity. (An illustration of these rooms and a staffing outline appear later in this fact sheet.)
System Engineering and Evaluation Room (SEER): The SEER is used by the HST subsystem engineers to perform in-depth subsystem analysis, to conduct simulated subsystem tests, to integrate new data bases, and to validate new ground software and updates to flight software. This room has the same capabilities as the MOR and also can be configured as a backup operations control room.
Payload Operations Control Center (POCC): The POCC is an essential element of the overall HST ground system. The POCC supports all HST activities by coordinating communication and data acquisition with MOR personnel and the NASA Network Control Center (NCC) at Goddard. This facility houses all application processor computers, data receiving and recording subsystems, telemetry and commanding equipment; and the communications equipment needed to achieve HST mission operations objectives.
Mission Support Room (MSR): The MSR directly supports day-to-day flight operations and engineering activities by providing off-line mission planning functions and data processing. MSR personnel provide the scheduling interface with the Network Control Center at Goddard, generate the science and engineering load for the onboard computers, and perform astronomy and engineering data processing. In addition, MSR analysts provide the updates necessary to maintain navigational integrity and pointing accuracy of the observatory.
Engineering Support System (ESS): The ESS supports mission
operations requirements for subsystem analysis and trending. It
provides near real-time and post analysis support using spacecraft
engineering data. This diagram shows the layout of the Secondary
Mission Operations Room (left) and the Mission Operations Room
(right). Abbreviations correspond to staffing locations.
Space telescope operations - including health and safety of the spacecraft, efficient operation and flight system engineering of the observatory - are the responsibility of NASA contractors under the Mission Operations, System Engineering and Software (MOSES) contract. The contract was implemented by the HST Operations and Ground System Project, which manages the space telescope. The following positions are staffed by MOSES personnel except for the Operations Manager, who is a civil servant:
The Operations Manager (OM) is NASA's space telescope project operational representative. The OM manages and provides technical direction to the Flight Operations Team during normal HST operations activities, engineering tests and simulations. This functional position assures project representation around the clock to meet day-to-day mission objectives. The OM, while on duty, is responsible for the overall operations and health and safety of the observatory in orbit.
The Shift Supervisor (SS)/Operations Controller (OC) is the lead member of each Flight Operations (FO) team. The SS/OC oversees the activities of all mission operations personnel on shift and has overall responsibility for assuring the real-time health and safety of the space telescope. The SS/OC coordinates and controls all real-time commanding of the HST. The SS/OC controls the on-line system capabilities and assignments at each console position, and coordinates the interface configurations with internal and external elements required to support mission operations. The SS/OC is the central point of contact for communications within the MOR and ensures that personnel adhere to responsible mission operations requirements.
The Science Instrument/Command and Data Handling/Pointing Control Subsystem Flight Controller is responsible for the health and safety of the science instruments, the science instrument command and data handling subsystem, and the pointing control system. This flight controller monitors the status of the onboard NSSC-1 computer, which controls the payload, and its interface with the onboard DF-224 engineering computer and the science instruments. This flight controller also monitors all vehicle slews and target acquisitions, and verifies the performance of the gyros, reaction wheels and safing system. The control ler also ensures that the optical telescope assembly is within thermal limits and monitors the status of the fine guidance sensors. The controller advises the SS/OC in the event of an anomaly involving these subsystems and recommends any action necessary to safeguard the vehicle or payload.
The Data Management Subsystem/Electrical Power Subsystem/Instrumentation
and Control/ Structures and Mechanisms Flight Controller monitors
the performance of the onboard DF-224 engineering computer and
performs onboard tape recorder management. This controller also
is responsible for the flow of commands to, and data from, the
space telescope and determines the proper data mode, telemetry
rate, format, and receiver and transmitter configurations to support
this function. The flight controller monitors the mode and quality
of the forward and return links between the HST and the Space
Network or the Ground Network and verifies the correct pointing
of the high-gain antennae.This flight controller also monitors
the performance of the space telescope's batteries during their
use in Earth's shadow and recharging in sunlight, and ensures
that the solar arrays are positioned correctly to maximize power
to the spacecraft. The controller advises the SS/OC in the event
of an anomaly involving these subsystems and recommends any action
necessary to safeguard the vehicle or payload.
Tammy Jones
Goddard Space Flight Center
Office of Public Affairs
(301) 286-5566
Internet: http://www.gsfc.nasa.gov
Space Telescope Science Institute
Office of Public Outreach
(410) 338-4707