As NASA moves forward into the 21st Century, many science missions are being considered that will require optics of unprecedented size. If the launches of these missions are to be affordable, then new technology must be developed to reduce the surface densities of the optical/mechanical systems from current hundreds of kilograms per square meter down to kilograms per square meter and tenths of kilograms per square meter. Also we must greatly increase the collecting aperture of telescope systems to hundreds and thousands of square meters without incurring current costs of mirror blank manufacture and polishing. To this end, a workshop was convened which brought together scientists and engineers to examine the optics requirements of these missions and to begin the process of identifying the technological developments required to bring these systems to reality. This paper describes the workshop, the general telescope architectures considered and identifies the initial assessment of the 'tall tent pole' technologies. Finally it gives an overview of the character of the approaches and the 'gossamer optics problems.'
The SPIE Education Committee has developed an outreach program aimed at enhancing the dissemination of information about optics to children in kindergarten through the 12th grade (K-12). The main impetus behind the program was that more practicing optical scientists and engineers would be willing to give lectures and demonstrations aimed at inspiring the next generation about optics if material could be made easily available. Consequently, three instructional `outreach kits' were assembled to use in teaching optics to kids in exciting and fun ways. These kits were beta-tested over the last two years at six different U.S. regional sites. Each `outreach kit' contained: (1) a workbook on Optical Demonstrations on the Overhead Projector; (2) a Science and Math Experience Manual: Light, Color and Their Uses; (3) The Optics Discovery Classroom Kit; (4) a slide show; and (5) a video on careers in optics. The best tests were aimed at evaluating the practical ways of utilizing the kits, developing easy-to-follow instructions for guiding others in their use and providing suggestions on modifications, additions, and deletions to the kits. This paper discuses this outreach program and provides details relative to the kit's composition and future plans.
The Next Generation Space Telescope is currently envisioned as an eight meter diameter cryogenic deployable telescope that will operate at the earth sun libration point L2. A number of different designs are being examined within NASA and under industry studies by Ball Aerospace, Lockheed- Martin and TRW. Although these designs differ in many respects, they all require significant advancements in the state-of-the-art with respect to large diameter, ultra- lightweight, mirrors. The purpose of this paper is to provide insight into the current status of the mirror development program.
The Hard X-Ray Telescope was selected for study as a possible new intermediate size mission for the early 21st century. Its principal attributes are: (1) multiwavelength observing with a system of focussing telescopes that collectively observe from the UV to over 1 MeV, (2) much higher sensitivity and much better angular resolution in the 10 - 100 keV band, and (3) higher sensitivity for detecting gamma ray lines of known energy in the 100 keV to 1 MeV band. This paper emphasizes the mission aspects of the concept study such as the payload configuration and launch vehicle. An engineering team at the Marshall Space Center is participating in these two key aspects of the study.
Initial core scan data of the VETA-1 X-ray mirror proved disappointing, showing considerable unpredicted image structure and poor measured FWHM. 2-D core scans were performed, providing important insight into the nature of the distortion. Image deconvolutions using a raytraced model PSF was performed successfully to reinforce our conclusion regarding the origin of the astigmatism. A mechanical correction was made to the optical structure, and the minor was tested successfully (FWHM 0.22 arcsec) as a result.
The energy bandwidth and total throughput of a grazing incidence optics system is a strong function of the X-ray reflectivity of the surface coating. In support of the Advanced X-ray Astrophysics Facility (AXAF), studies are underway to evaluate and characterize the reflectivity of potential AXAF coatings. Here we report on results obtained for Au, Ir, and Ni coatings produced by electron-beam evaporation, evaporation with ion-assist, and sputtering. Effects of coating thickness and deposition angle have been evaluated at 6.4 and 8.1 keV; the highest reflectivities are those of the thinner, about 200 A vs about 700 A, coatings. While considerable variations exist, the best Ir samples have higher reflectivity than any of the Au coatings. Data results have been compared with models for theoretical reflectivity, particularly with regard to the effective density of the coatings. Independent measurements of the coating densities have been carried out for comparison with the reflectivity results.