Space Sciences

One of the Institute’s strengths is the development of scientific payloads aboard space shuttles, scientific satellites, and sounding rockets. Institute teams formulate concepts, design and manage complex hardware and data systems, develop advanced spaceborne instrumentation, and address theoretical aspects of space physics and planetary astronomy.

A Thermal Ion Dynamics Experiment (TIDE), developed for NASA, measures the composition and velocity distribution of low-energy ions flowing from the ionosphere. Containing SwRI-developed time-of-flight technology, TIDE is the most sensitive spaceborne ion mass spectrometer ever built — improved by a factor of 100 over its predecessors. TIDE has been integrated with the Global Geospace Science Program’s Polar spacecraft, to be launched in December 1995. The Polar spacecraft will also carry the Toroidal Ion Mass and Angle Spectrograph (TIMAS), for which SwRI built the data processing unit. Operating in a higher energy range than TIDE, TIMAS will provide complementary data. These instruments and others will supply a comprehensive picture of ionospheric and magnetospheric plasmas.

Technicians assemble Particle Environment Monitor (PEM) instrumentation, developed to measure energy in the Earth's upper atmosphere deposited by electrons and positive ions with energies up to several million electron volts. PEM was launched aboard NASA's Upper Atmosphere Research Satellite in September 1991. Data analysis and computer modeling efforts will continue through September 1997.

The Institute is providing high-voltage power supplies and data processing electronics for NASA’s Lunar Prospector Discovery mission. The Discovery program is an example of NASA’s approach to flying smaller and less expensive missions to the planets and moons of the solar system. In an effort to understand the origin and evolution of the Earth and its moon, Lunar Prospector will use remote sensing to determine the moon’s composition, crustal structure, and magnetic field. After the mission is launched in 1997, SwRI will participate in analysis and scientific interpretation of the data.

SwRI is developing the Cassini Plasma Spectrometer (CAPS) to investigate the composition and dynamics of plasma in Saturn's magnetosphere. Finite element models of CAPS are used to evaluate the instrument's performance and interaction with the spacecraft.

SwRI is cooperating with 13 other scientific institutions in the U.S. and Europe to develop the Cassini Plasma Spectrometer (CAPS), which will investigate the composition and dynamics of plasma in Saturn’s magnetosphere. Understanding the plasma could help scientists answer questions regarding how the magnetosphere was formed, how it alters the appearance of Saturn and its satellites and rings, and what causes the Saturnian aurora. After assembling and testing CAPS at SwRI, an engineering model will be delivered to the Jet Propulsion Laboratory in early 1996 for spacecraft integration and testing. Immediately following delivery, the CAPS team will assemble and test the flight model, which will be launched on a trajectory to Saturn aboard a Titan IV rocket in October 1997.

With internal funding, SwRI has devised a novel approach to small, low-cost sensors for space applications. The Miniaturized Optimized Smart Sensor (MOSS) prototype is included on several NASA payloads under study. These include the Solar Probe, which will fly to within 4 solar radii of the sun to probe its atmosphere; the Grand Tour Cluster, which will measure charged particles and fields within the Earth’s magnetosphere; and the New Millennium program, which will prove out new technology for future missions to comets, asteroids, and Mars. Among the technologies developed for MOSS are high-voltage power supplies used for detector bias voltages that generate potentials up to 4 kilovolts, weigh only 30 grams, and use only 80 mW of power — a size and power reduction of about 65 percent over conventional spaceborne power supplies.

SwRI is taking the lead in developing small, low-power mass spectrometers for space flight. One approach, proposed for a NASA Mars Lander in cooperation with the University of Texas at Dallas, is to update a traditional mass spectrometer design with state-of-the-art detectors, electronics, and sample inlet systems. Another approach, in cooperation with the Westinghouse Science and Technology Center, is to use modern micromachining technology to manufacture a mass spectrometer on a chip (MASC). The MASC is expected to weigh less than 600 grams while providing the performance of instruments nearly 10 times its size.

The SwRI-developed Extreme Ultraviolet Spectrometer (EUVS) sounding rocket was successfully launched April 15, 1995, for its third flight in a year. During a rare lunar occultation of the bright ultraviolet star Spica, the EUVS used the star as an ultraviolet source to look for absorption features caused by atmospheric constituents in the lunar atmosphere. The primary and secondary launch windows were carefully chosen so the EUVS payload could observe Spica pass through the lunar atmosphere to the lunar limb (the edge of the lunar disk as seen from the Earth), where the moon’s atmosphere has the highest column density. Data analysis is under way.

Institute scientists maintain an active program in outer planet research, including theoretical modeling and observations, with recent emphasis on the Jovian aurora. Observations of a powerful auroral event were obtained using the Hubble Space Telescope in collaboration with a European observation team, led by the University of Liege in Belgium. The results, published in the December 1994 issue of Science, demonstrate that the auroral energy input at Jupiter is sufficient to blow off large portions of the upper atmosphere during energetic events.

SwRI also enjoyed a unique opportunity to observe Jupiter during its July 1994 impact with comet Shoemaker-Levy 9. Satellite-based X-ray observations revealed dramatic bursts from Jupiter’s northern auroral zone associated with the impacts of two cometary fragments. The unexpected X-ray bursts, which were reported in the June 1995 issue of Science, are still unexplained and are being studied through a computer modeling project funded by the National Science Foundation.

The Institute is leading the development of RAD6000-based control units for the Space Station Furnace Facility, which will be used for zero-g manufacturing and materials processing experiments that will be transported to the space station by the space shuttle. RAD6000 is the radiation-hardened version of the processor used in the IBM R6000 Reduced Instruction Set Computer workstation. The control unit program is a joint effort with Loral Federal Systems-Manassas and Spectrum Astro, Inc.

An SwRI-developed ultracompact spaceflight computer, called MOPS6000, can deliver 25 million instructions per second. it is the first module in the SwRI family of miniature 32-bit processing systems for space that will include additional solid state memory and input/output devices.

SwRI is developing the first two modules of a miniaturized multimission spacecraft control subsystem. The Miniaturized Optimized Processor for Space-RAD6000, or MOPS6000, is an ultracompact spaceflight computer approximately 300 cubic centimeters in size with a mass of 350 grams, delivering 25 million instructions per second. The Space Adaptable Memory Module, or SpAMM, complements MOPS6000 by providing dense, scalable, nonvolatile gigabyte mass memory in a small, lightweight package. High-density multichip modules and staked memory dies are used in SpAMM to deliver a memory density of 84 megabytes per cubic inch. Both MOPS6000 and SpAMM will be adapted for commercial standard architecture.

SwRI has developed an advanced spaceflight computer and electronic controller for an expendable space launch vehicle. The units perform attitude sensor data fusion and control functions for the Scorpius launch vehicle. During the project, sponsored by the U.S. Air Force Phillips Laboratory, liquid-propellant rockets will be delivered and test- fired by 1996. The program uses existing low-cost technologies and focuses on improved manufacturing to ensure reliable system operation. Goals are to develop an economical family of light-, medium-, and possibly heavy-lift expendable launch vehicles.

The Institute is developing an 80386-based spaceflight computer to use as the robot arm control computer for the shuttle-based Japanese Experiment Module Flight Demonstration. The robot arm is targeted for use on the space station. A demonstration is planned for late 1997 on the space shuttle to provide zero-g performance data on the structure and control algorithms for the arm.

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