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Ahlf, P. R.

Publications and source records attributed to Ahlf, P. R..

Space Station Freedom Integrated Research and Development Growth

Space Station Freedom is designed to be an Earth-orbiting, multidiscipline research and development (R&D) facility capable of evolution to accomodate a variety of potential uses. One evolution scenario is growth to an enhanced R&D facility. In support of the Space Station Freedom Program Preliminary Design Review (PDR), the NASA Langley Research Center Space Station Office is analyzing growth requirements and evaluating configurations for this R&D utilization. This paper presents a summary of FY1989 study results including time-phased growth plans, R&D growth issues and configurations, and recommendations for the program baseline design which will facilitate evolutionary R&D growth. This study consisted of three major areas of concentration: mission requirements analysis; Space Station Freedom systems growth analysis; and growth accomodations and trades. Mission requirements analysis was performed to develop a realistic mission model of post-Phase 1 R&D missions. A systems-level analysis was performed to project incremental growth requirements of Space Station Freedom needed to support these R&D missions. Identification of growth requirements and specific growth elements led to the need for special accomodations analyses and trades. These studies included identification of hooks and scars on the baseline design, determination of an optimal module growth pattern, analysis of the dual keel length, and determination of an optimal locaton for the customer servicing facility. Results of this study show that Space Station Freedom must be capable of evolving to a dual keel, eight pressurized module configuration (two growth habs and two growth labs); providing 275 kW power (for experimenters and station housekeeping); accomodating a crew of 24; and supporting other growth structures and special facilities to meet projected R&D mission requirements.

Meredith, Barry D.↗

Space Station Freedom growth power requirements

Options and scenarios for the evolution of Space Station Freedom beyond the current baseline have been established and analyzed at NASA Langley Research Center to identify growth requirements for the program's Preliminary Requirements Review (PRR). Time-phase requirements for electrical power and other critical resources were determined based upon the future needs of the science, technology and commercial users. In addition, impacts and resource growth were determined for the utilization of station as a transportation node in support of human exploration initiatives to the moon and/or Mars. The set of requirements chosen for the PRR were selected on the basis of their adequacy in accommodating each of the evolution options and scenarios within each option, thereby maximizing future flexibility. In the case of electrical power, growth to 275 kW (average) was determined to be adequate for evolutionary missions and station housekeeping growth, given projections of future earth-to-orbit transportation capabilities.

Meredith, B. D.↗

The role of Space Station Freedom in the Human Exploration Initiative

Exploration accommodation requirements for Space Station Freedom (SSF) and mission-supporting capabilities have been studied. For supporting the Human Exploration Initiative (HEI), SSF will accommodate two functions with augmentations to the baseline Assembly Complete configuration. First, it will be an earth-orbiting transportation node providing facilities and resources (crew, power, communications) for space vehicle assembly, testing, processing and postflight servicing. Second, it will be an in-space laboratory for science research and technology development. The evolutionary design of SSF will allow the on-orbit addition of pressurized laboratory and habitation modules, power generation equipment, truss structure, and unpressurized vehicle processing platforms.

Ahlf, P. R.↗

On orbit mission planning using the shuttle trajectory and launch window expert system

With the Space Transportation System (STS) entering the operational era, the need for standardized, automated, mission planning computer tools has become apparent. In order to support an increased flight rate without an increase in manpower, quicker and more efficient methods are needed to perform standard tasks. The Shuttle Trajectory and Launch Window Expert System (STALEX) was developed to automate many aspects of early mission planning for space shuttle missions carrying geosynchronous communications satellites. Most of the commercial Shuttle missions planned for the next 3 years will carry at least one of this type of satellite. The applications of STALEX include payload deployment scheduling, launch window analysis, orbital trajectory determination, and landing opportunity selection.

Ahlf, P. R.↗