Site: The Goddard Space Flight Center
Greenbelt Road
Greenbelt, MD 20771
http://pao.gsfc.nasa.gov

Date Visited: July 29, 1997

WTEC: Neil Helm

Hosts:

BACKGROUND

The Goddard Space Flight Center (GSFC) was established in 1959 as a space and science center. It has some 11,750 employees of which 8,400 are contractors. The GSFC budget for FY96 was $28 billion. GSFC is NASA's lead center for the Mission to Planet Earth and is currently constructing an Earth Observing System Data and Information System that will have one of the largest real time data archiving and distributing systems in the world. Other major missions include the Hubble Space Telescope, the GOES weather satellite system, and the Tracking and Data Relay Satellite System (TDRSS) project. A recent addition to the center is the Systems Technology and Advance Concepts Office that is to provide end-to-end systems engineering for advanced mission support.

RESEARCH AND DEVELOPMENT ACTIVITIES

High Performance Computing and Communications

The Earth and Space Data Computation Division is a leading center for high performance computing and communications research. It uses supercomputers, high speed networks and advanced visualization equipment to support over 1,000 remote scientists with near real time technical data. Using the CRAY T3E, 512 processor supercomputer, research scientists have sustained performance of scientific data at over 50 gigaflops. In benchmark tests, the T3E performed at 176 gigaflops. Within this computation division, high performance computing and communications research is also performed by the Center of Excellence in Space Data and Information Sciences, and the Center for Satellite and Hybrid Communications, both associated with the University of Maryland.

In communications research, hybrid terrestrial and satellite testing and experiments are taking place with the ACTS satellite at speeds up to 622 Mbps (OC-12). The GSFC ACTS high data rate ground terminal is connected to the Advanced Technology Demonstration network (ATDNet), a 2.5 Gbps fiber ring around the Washington, D.C. area. This allows for the GSFC terminal to do advanced communications and networking research with other government agencies such as the DOD and NIH, and connect these agencies via satellite to other high performance research networks such as the MAGIC testbed in the Middle West.

Data Broadcast (Direct Read Out)

In preparation for the Mission to Planet Earth, Earth Observation System's Data Information System (EOSDIS) the Earth and Space Data Computation Division is working on information systems that can distribute large amounts of data that will go directly from the spacecraft's onboard scientific instrument to the data archive centers and/or the scientists in the field. The direct read out of these data will be sent via the Internet, Intranets and direct broadcast satellite networks that will be contracted with commercial broadcast satellite providers.

Tracking and Data Relay Satellite System (TDRSS) Project

The TDRSS project came out of the requirement to increase the spacecraft tracking capability for NASA missions, especially LEO Space Shuttle missions, and relay data from LEO orbiters via the GEO TDRSS to the NASA terrestrial network. Also, this eliminated some dependence on offshore tracking stations. The TDRS System has worked well with the six spacecraft that reached GEO still operating. Three additional spacecraft "H, I & J" are currently being built by Hughes in Los Angeles. These spacecraft will add Ka-band capability to the current S and Ku-band configurations that will greatly increase the overall capacity of the data system. Also, the new spacecraft will be able to be co-located with any of the older satellites to maximize the use of good orbit locations and allow a natural backup or transition capability. The newer spacecraft will employ a number of technical advances including a nearly two to one improvement in pointing accuracy for tracking, and improved attitude control, especially needed for Ka-band requirements. They will also utilize a solar sailing technique with the large antennas and solar arrays acting like sails to conserve fuel and stabilize roll/yaw momentum.

CONCLUSIONS

GSFC is a modern space and earth science center with the Mission to Planet Earth data distribution function becoming an important and highly visible addition to its current missions and projects. Also, GSFC should benefit from the smaller/faster/cheaper NASA philosophy, as it has a good reputation for the design and conduct of smaller science projects and from the addition of the Systems Technology and Advanced Concepts Office that will provide end-to-end systems engineering for advanced mission support for new projects.


Published: December 1998; WTEC Hyper-Librarian