Technical Areas of Interest
Space Telescope Technology (NGST)
In 1608, Lippershey invented the telescope. A year later, Galileo built a telescope with a collecting area 60 times greater than that of the human eye. The premier astronomical telescope today is the Hale telescope located on Mt. Palomar in Southern California. The Hale has a collecting area of four orders of magnitude larger than the Galileo telescope. Although the Hale was constructed in 1948, the fact that it remains astronomy's premier instrument indicates how difficult and expensive it is to solve the problems associated with the design and fabrication of large optical systems. To increase the collecting area of the telescope, it will require a new technique that employs new technology using an array of smaller telescopes coupled optically and mechanically, providing a combined collecting area many times larger than that of the individual elements. An example of this technique is the Multiple Mirror Telescope (MMT) on Mt. Hopkins in Arizona. The MMT uses six 2-m primary mirrors on a single mount with special optics to combine the beams into a single focus. NASA researchers have also identified the need for very large precision reflectors to implement near-future missions in both astrophysics and spacecraft communications. A high-performance astronomical instrument capable of unprecedented ground-based observations in both visible and infrared portions of the spectrum is the M. Keck Observatory Ten-Meter Telescope (TMT) located on Mauna Kea in Hawaii.
Astronomers have uncovered tantalizing clues in images taken by the Hubble Space Telescope (HST) as well as in data gathered by the Cosmic Background Explorer (COBE). To see the first generations of stars, the science community believes it will need a successor to HST. Even with new instruments, its observations are limited. The younger objects, which are receding from us at an ever-faster rate, are red-shifted into the rear infrared (past 2 microns) where Hubble loses sensitivity. The Next Generation Space Telescope (NGST) with its large light-gathering mirror and superb resolution will be capable of detecting faint signals from the first billion years, the period when galaxies formed. CSULA's Precision Segmented Reflector Program, sponsored by NASA under the IRA program, serves as a first step in the development and validation of the enabling technologies that ultimately will be used by the NGST mission in 2009.
The proposed research will build and expand on the existing IRA program currently under way at the SPACE (Structures Pointing And Control Engineering) laboratory at CSULA [53-84]. Advanced technologies for fault identification, precision pointing, and reconfigurable control will be developed and experimentally validated on the SPACE testbed. Due to the nature of the structure, the research will employ decentralization techniques [85-92] for the development of control laws to accomplish precision pointing with an accuracy of 2 arc seconds. Design of control laws will be based on various approaches including robust control and neural networks. A system identification task will be responsible for tuning the dynamic models used for controller design.