instance, in the life sciences alone, more than 580 graduate students and postdoctoral associates were receiving some level of support through OBPR grants in FY 2000.
Evidence of significant contributions from investigators in many areas of research in the microgravity environment was noted. The contributions included a more fundamental understanding of convection and solidification, diffusion processes and liquid-phase sintering, critical differences in fire sensing and control in microgravity, and development of tissue-engineered artificial bone and cartilage matrices. In FY 2000 alone there were over 1600 articles printed in peer reviewed publications by OBPR-funded investigators and another 174 books or book chapters3 based on OBPR-funded work. Future research that could be optimally performed on the ISS includes experiments from all disciplines. A few examples (noninclusive) are as follows:
Effect of long-term exposure to microgravity on various aspects of physiology and human behavior—for example,
Bone and muscle loss and evaluation of therapies to prevent these losses;
Immunological responses in animals and humans;
Development of the vestibular system in animal models such as rodents; and
Neurovestibular function and development.
Studies on the effects of microgravity on physical phenomena, such as the following:
Extension of the study of critical-point phenomena;
Study of interfacial dynamics affecting crystal growth and liquid-phase sintering; and
Determination of fundamental limits and parameters of combustion phenomena, as well as development and validation of techniques for fire sensing and control in microgravity.
Readiness is also attested to by the long list of experiments that have already been peer reviewed and approved for flight. In recent years the overall success rate of research proposals submitted to OBPR has averaged about 20 percent, with about one in seven of the successful proposals selected for the flight program. As shown in Tables 2.1, 2.2, and 2.3, there is a sizable group of selected flight experiments in all disciplines for ISS. There was general agreement across disciplines that there are fundamental scientific insights to be gained by doing these experiments in the prolonged microgravity environment on the ISS. In addition to allowing assessment of potentially cumulative effects of exposure to microgravity, this environment would also allow iterative modifications of experimental parameters in an efficient and timely manner.