Payload Developers Research Articles

Safety analysis of evaluation and acceptance processes for space systems and operations based on system-theoretic approach

The proposed analysis consists of identifying systemic aspects that can influence safety and mission fulfillment in the Evaluation and Acceptance Processes of Space Systems and Operations for Launch through the application of System-Theoretic Process Analysis, a technique capable of identifying potential hazardous design and operational flaws, including system design errors and unsafe interactions among multiple procedures and system components. This research identifies losses, hazards, system-level safety constraints, the control structure of the general system, unsafe control actions, loss scenarios that could occur and related causal factors, detecting improvement possibilities for future verifications, evaluations, approvals, and acceptances of space systems and launch operations. These findings can promote safety in space system designs and operations, supporting the activities conducted by launch vehicle and payload developers, certification authorities, and launch centers management, enabling means to proactively act in order to mitigate risks, avoiding unsafe actions and undesired system behaviors, or even to mitigating their consequences. The practical applications of this work can result in safety and mission fulfillment improvements for safety management systems, launch approval regulations and standards; launch operation procedures; space systems design; vehicle, payload, and ground support equipment productions; systems testing; and launch authorization processes.

Research progress and accomplishments on International Space Station

The first research payloads reached the International Space Station (ISS) more than two years ago, with research operating continuously since March 2001. Seven research racks are currently on-orbit, with three more arriving soon to expand science capabilities. Through the first five expeditions, 60 unique NASA-managed investigations from 11 nations have been supported, many continuing into later missions. More than 90,000 experiment hours have been completed, and more than 1,000 hours of crew time have been dedicated to research, numbers that grow daily. The multidisciplinary program includes research in life sciences, physical sciences, biotechnology, Earth sciences, technology demonstrations as well as commercial endeavors and educational activities. The Payload Operations and Integration Center monitors the onboard activities around the clock, working with numerous Principal Investigators and Payload Developers at their remote sites. Future years will see expansion of the station with research modules provided by the European Space Agency and Japan, which will be outfitted with additional research racks.

Design and construction of a convertible hemi/anechoic acoustical laboratory for testing space flight hardware at the NASA Glenn Research Center

At the NASA Glenn Research Center, science experiment payloads developed for the International Space Station are designed to meet noise emission criteria that promote hearing conservation and speech intelligibility goals. A key component in the successful design of low-noise hardware is the frequent use of acoustical testing as a diagnostic and design verification tool. NASA has designed and constructed a convertible hemi/anechoic acoustical testing laboratory that provides convenient access to accurate and repeatable sound pressure level measurements as well as state-of-the art capabilities for sound power level testing per ANSI S12.35 using a multichannel PC-based data acquisition system. The laboratory consists of a 100-Hz hemianechoic chamber, vibration-isolated to 3 Hz, with 21′×17′×17′(h) interior working dimensions and removable floor wedges. A separate, sound-isolated control room doubles as a test support equipment enclosure when testing flight hardware that requires remote connections to high-noise support equipment and utilities. Movable modular furnishings facilitate reconfiguration of the enclosure, and data acquisition and test control functions are easily relocated to an adjacent quiet area. The Glenn Research Center Acoustical Testing Laboratory also offers a full range of noise control services to assist payload developers with meeting the ISS noise emission criteria.