Space acceleration measurement system for free flyers (SAMS-FF) - Initial test results

Abstract

Scientists from fluids, combustion, materials, and life sciences disciplines experiment in space to enhance understanding of fundamental physical phenomena. Space conditions reduce gravity but do not eliminate it completely. There can be disturbances caused by spacecraft maneuvers, equipment operations, atmospheric drag, and for manned flights, crew movements that can affect these experiments. Therefore, researchers measure spacecraft microgravity (u.g) to characterize the spacecraft, measure experiment conditions, and manage the u.g environment. The quantification of the u,g environment removes this unknown from the experiment post-flight data analysis. The SAMS-FF system has made new progress in p.g measurement, especially by being a compact and flexible system. INTRODUCTION NASA's Lewis Research Center (LeRC) has developed a new microgravity measurement system called Space Acceleration Measurement System for Free Flyer spacecraft (SAMS-FF). This new system is developed from the heritage of the original SAMS, which has flown eighteen missions on the space shuttle and the Russian Space Station Mir. Another system, designated SAMS-II, is under development at LeRC for the International Space Station. SAMS-II developed digital output sensor heads. Both SAMS-II and SAMS-FF incorporate advanced techniques in analog-to-digital conversion (ADC) which reduce noise and increase operating flexibility. These systems are complementary as they are intended for different applications. • SAMS-FF Contractor Project Lead t SAMS-FF Project Manager Copyright© 1998 by American Institute of Aeronautics and Astronautics, Inc. No copyright is asserted in the United States under Title17, U.S. Code. The U.S. has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner. The Microgravity Measurement and Analysis Project (MMAP) at LeRC developed SAMS, SAMS-II, and SAMS-FF. The mission statement for MMAP includes providing principal investigators microgravity data during on-orbit operations, and u.g environment characterization of selected carriers. This paper describes the design and development of SAMS-FF. This system was developed as a flexible, modular system easily configured to meet requirements for a broad variety of missions to support the collection of microgravity measurements. The system is configurable for short or long duration missions. A compact Control and Data Acquisition Unit (CDU) is configurable and incorporates a real-time operating system. Data storage can be scaled to meet mission requirements. Three different types of sensors are incorporated to measure different spectrum of the (ig regimes. All three sensors can be operated standalone (without the CDU) when combined with an embedded system or computer platform. Some results of the characterization testing performed to support the first flight of SAMS-FF is presented. Data is shown from the test demonstration flight supporting a combustion experiment on a sounding rocket.