• That NOAO further reduce its support of those telescopes with relatively low oversubscription rates, seeking arrangements, whenever possible, to transfer them to private institutions.

• The NOAO should endeavor to increase the time it can make available on 4-m class telescopes by seeking more partnership arrangements like the several efficient cost-sharing arrangements with university consortia that it has recently undertaken.

• NSF-astronomy and NOAO should establish provisions for trading or purchasing telescope time from private and university groups operating 8-m and 10-m class telescopes and smaller special-purpose telescopes in order to ensure that the full range of observing facilities is available to the whole community. Astronomy in the U.S. would be well served by a cooperative interdependency of the private and public sector.

• By adding 8-m telescopes, NOAO will continue to fulfill its mission of providing access to front-line facilities to all astronomers independent of institutional affiliation. The construction and operation of 8-m telescopes and a 4-m telescope dedicated to fiber optics spectroscopy, and technology development for optical and infrared interferometry, are also important steps for development of a technical base upon which even more ambitious, unique facilities will be built.

  The development of unique facilities, which are distinguished either by scale or function, is a crucial step by which NOAO can broaden its support of the entire astronomical community. To maintain leadership in optical astronomy, NOAO needs the active involvement of the nation's leading astronomers, including those with access to private 4-m, 8-m and 10-m telescopes. They must be involved in the definition of NOAO projects and their implementation, and most importantly, they must use these facilities. The presently planned 8-m telescopes for NOAO are an important step along the way. A larger world-class, unique facility for optical astronomy will be needed to ensure scientific leadership by NOAO and to exploit fully the U.S. advantage of combining powerful resources in both the private and public sector.

• NOAO cannot be the site for all of the necessary technological innovation, but it can play a vital role as a clearinghouse for such technology. To this end, NOAO should encourage outside partnerships in detector and instrument development.

The health and success of U.S. optical astronomy has been based on a combination of a strong national observatory together with non-federal funding for private and university facilities that is unique in the world. A partnership that enhances the strengths of these two elements will ensure continued U.S. leadership in optical astronomy.

NASA's agenda of unfinished astrophysics missions remains substantial. For example, the HST needs repair, SIRTF has not yet been started, and AXAF and most of the Explorer missions approved during the 1970's and 80's will not be launched until the late 1990's.

OSSA's five year strategic plan incorporates this unfinished agenda. We endorse this plan without reservation. In doing so, we recognize that its completion establishes NASA's strategy for most astrophysics missions to be launched until the late 1990's. Therefore, our recommendations cannot affect this plan in a major way. They should, however, affect the process by which NASA will select and implement astrophysics missions to be started during this decade and beyond.

We recommend that NASA develop a more vigorous program of missions with reduced complexity and shorter times from inception to completion. At present, the funding is weighted toward large missions costing more than $300 M, such as HST, GRO, and AXAF. Averaged over 1984 - 1989, the fraction of NASA astrophysics project funding devoted to large missions was 73%, compared to 12% for moderate ($100 - 300 M) missions and 15% for small (< $100 M) missions, including rockets, balloons, and aircraft.

Large missions such as the Great Observatories have revolutionary capabilities that cannot be matched by moderate and small missions. The latter, however, can add a dimension to NASA's space science program that is vital and cannot be provided by the large missions: the ability to deploy new instrumental technology into space on a timescale of a few years. The prospect of rapid access to space is a strong