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NASA NTRSDate not supplied

X-37 Flight Demonstrator Project: Capabilities for Future Space Transportation System Development

The X-37 Approach and Landing Vehicle (ALTV) is an automated (unmanned) spacecraft designed to reduce technical risk in the descent and landing phases of flight. ALTV mission requirements and Orbital Vehicle (OV) technology research and development (R&D) goals are formulated to validate and mature high-payoff ground and flight technologies such as Thermal Protection Systems (TPS). It has been more than three decades since the Space Shuttle was designed and built. Real-world hardware experience gained through the multitude of X-37 Project activities has expanded both Government and industry knowledge of the challenges involved in developing new generations of spacecraft that can fulfill the Vision for Space Exploration.

Daniel L Dumbacher↗
NASA NTRS2006

Jet Propulsion Laboratory: Annual Report 2005

What an amazing host of new sights 2005 brought us. With impeccable choreography, one spacecraft sent an impactor slamming into a comet, reversing the traditional view of these space wayfarers by revealing it to be buried in deep drifts of a fine talcum-like powder. Another spacecraft delivered a probe from our European partners to the surface of Saturn's haze-shrouded moon Titan, disclosing a landscape eerily like Earth's, if we had methane rivers cascading down hillsides of ice. An orbiting observatory for the first time showed us the light from planets circling other stars, which astronomers previously knew to exist only from indirect clues. Throughout the year we also amassed continually expanding views of Earth as well as Mars, by far the most-explored planet after our own. In all, 18 spacecraft and five instruments were stationed across the solar system, studying our own world, other planets, comets and the deeper universe. These missions were enabled by the efforts of everyone at JPL. The Deep Space Network of communications complexes across three continents continued to experience a period of remarkable activity. Others were at work creating technologies both for NASA missions and other uses. JPL's contingent of scientific researchers was equally busy coordinating the science activities of our missions or pursuing independent investigations. None of this would be possible without the support of world-class business and administrative teams. All of our missions in one way or another support our nations Vision for Space Exploration, which envisages a gradually widening robotic and human presence across the solar system in the years ahead. The year was not without its challenges. NASA set forth to implement the Vision for Space Exploration, which resulted in some flight projects and technology efforts being terminated. To adjust to this new direction, it was necessary for us to reduce the JPL workforce by about five percent. Taking steps like this is painful, but we tried to make the process as orderly as possible. In the end, the adjustments made have left JPL on a healthy footing for the years ahead.

Jet Propulsion Laboratory (JPL)↗
NASA NTRS1991

Microgravity vibration isolation: An optimal control law for the one-dimensional case

Certain experiments contemplated for space platforms must be isolated from the accelerations of the platform. An optimal active control is developed for microgravity vibration isolation, using constant state feedback gains (identical to those obtained from the Linear Quadratic Regulator (LQR) approach) along with constant feedforward gains. The quadratic cost function for this control algorithm effectively weights external accelerations of the platform disturbances by a factor proportional to (1/omega) exp 4. Low frequency accelerations are attenuated by greater than two orders of magnitude. The control relies on the absolute position and velocity feedback of the experiment and the absolute position and velocity feedforward of the platform, and generally derives the stability robustness characteristics guaranteed by the LQR approach to optimality. The method as derived is extendable to the case in which only the relative positions and velocities and the absolute accelerations of the experiment and space platform are available.

Hampton, Richard D.↗
NASA NTRS1998

Experiment 9: ASTROCULTURE: Growth and Starch Accumulation of Potato Tuber

Potato explants (leaf, small stem section, and axillary bud) flown on STS-73 developed tubers of 1.5 cm diameter and 1.7 g mass during the 16-day period of space flight. The experiment was undertaken in the ASTROCULTURE(TM) experiment package under controlled temperature, humidity, lighting, and carbon dioxide concentrations. The tubers that formed in the explant system under microgravity had the same gross morphology, the same anatomical configuration of cells and tissues, and the same sizes, shapes, and surface character of starch granules as tubers formed in a 1 g environment. The total accumulation of starch and other energy containing compounds was similar in space flight and ground control tubers. Enzyme activity of starch synthase, starch phosphorylase, and total hydrolase was similar in space flight and ground controls, but activity of ADP-glucose pyrophosphorylase was reduced in the space flight tuber tissue. This experiment documented that potatoes will metabolize and accumulate starch as effectively in space flight as on the ground. Thus, this data provides the potential for effective utilization of potatoes in life support systems of space bases.

Tibbitts, Theodore W.↗
NASA NTRS1991

Microgravity vibration isolation: An optimal control law for the one-dimensional case

Certain experiments contemplated for space platforms must be isolated from the accelerations of the platforms. An optimal active control is developed for microgravity vibration isolation, using constant state feedback gains (identical to those obtained from the Linear Quadratic Regulator (LQR) approach) along with constant feedforward (preview) gains. The quadratic cost function for this control algorithm effectively weights external accelerations of the platform disturbances by a factor proportional to (1/omega)(exp 4). Low frequency accelerations (less than 50 Hz) are attenuated by greater than two orders of magnitude. The control relies on the absolute position and velocity feedback of the experiment and the absolute position and velocity feedforward of the platform, and generally derives the stability robustness characteristics guaranteed by the LQR approach to optimality. The method as derived is extendable to the case in which only the relative positions and velocities and the absolute accelerations of the experiment and space platform are available.

Hampton, R. D.↗
NASA NTRS1992

Optimal microgravity vibration isolation - An algebraic introduction

Certain experiments contemplated for space platforms must be isolated from the accelerations of the platforms. An optimal active control is developed for microgravity vibration isolation, using constant state feedback gains (identical to those obtained from the Linear Quadratic Regulator (LQR) approach) along with constant feedforward (preview) gains. The quadratic cost function for this control algorithm effectively weights external accelerations of the platform disturbances by a factor proportional to (1/omega) (exp 4). Low frequency accelerations (less than 50 Hz) are attenuated by greater than two orders of magnitude. The control relies on the absolute position and velocity feedback of the experiment and the absolute position and velocity feedforward of the platform, and generally derives the stability robustness characteristics quaranteed by the LQR approach to optimality. The method as derived is extendable to the case in which only the relative positions and velocities and the absolute accelerations of the experiment and space platform are available.

Hampton, R. D.↗
NASA NTRSDate not supplied

Designing Autonomy into Interfaces for Long-Duration Missions

As NASA develops technologies for long-duration crewed missions, we must understand how communication between ground control teams and astronauts differs from the current dynamic to adapt new concepts for long-duration mission operations. Today, ground control teams support astronauts with immediate availability to answer questions, resolve issues, and manage activities. In the near future, however, extended communication delays during long-duration missions will require astronauts to become more autonomous. As many of the responsibilities shift from the ground control teams to the astronauts on-board, the concept of operations must also change from how it functions today. With increased astronaut autonomy, software tools must be developed that enable efficient completion of mission tasks without increased mental workload. Designing software tools to facilitate crew autonomy requires development teams to know which data will enhance quick decision making while providing necessary context for situational awareness of systems being managed on-board. NASA's Autonomous Systems and Operations (ASO) team is presently developing a software interface tool, EXPRESS (EXpedite the PRocessing of Experiments for Space Station) 2.5 to enable a long-duration crew to schedule activities for and operate autonomous systems. This paper describes details of the integrated human factors approach that drove the design of the elements of the software tool, including self-managed scheduling, constraint-driven planning, autonomous system fault recovery, and recommended troubleshooting actions. Additionally, this paper will chronicle ASO modifications of the user interface after the team's first flight demonstration, how it was based on lessons learned during software development, as well as from crew feedback in order to develop the current version which will be demonstrated on ISS in 2021. In the upcoming ISS demonstration, the astronaut crew will be given scenarios for scheduling and operating autonomous system activities, including off-nominal scenarios and autonomous system recoveries. The demonstration of the EXPRESS 2.5 tool is a step towards improved levels of autonomy as our new journeys take us farther into space.

autonomy↗
NASA NTRS2000

Monitoring on the Move

The MyoMonitor EMG system was developed by Delsys, Inc. under SBIR funding from Johnson Space Center. It is a wearable four-channel device that can monitor muscle performance. Presently, its application include rehabilitative therapy, injury prevention, sports medicine, exercise training, and various other muscle monitoring activities. The MyoMonitor uses a two-bar single differential electrode. Due to the electrode-skin interface in traditional EMG equipment, during rigorous muscular activity, the movement of the skin causes the electrode detection surfaces to become compromised. The MyoMonitor eliminates this problem, enabling a wide array of applications and experiments during intense muscular activity. The ability to make such recordings, for example, enables novel experiments aboard the International Space Station for investigating the effect of microgravity on muscle performance. Product still commercially available as of March 2002.

Source record↗
NASA NTRS1996

STS-72 Space Shuttle Mission Report

The STS-72 Space Shuttle Program Mission Report summarizes the Payload activities as well as the Orbiter, External Tank (ET), Solid Rocket Booster (SRB), Reusable Solid Rocket Motor (RSRM), and the Space Shuttle main engine (SSME) systems performance during the seventy-fourth flight of the Space Shuttle Program, the forty-ninth flight since the return-to-flight, and the tenth flight of the Orbiter Endeavour (OV-105). In addition to the Orbiter, the flight vehicle consisted of an ET that was designated ET-75; three Block I SSME's that were designated as serial numbers 2028, 2039, and 2036 in positions 1, 2, and 3, respectively; and two SRB's that were designated BI-077. The RSRM's, designated RSRM-52, were installed in each SRB and the individual RSRM's were designated as 36OW052A for the left SRB, and 36OW052B for the right SRB. Appendix A lists the sources of data, both formal and informal, that were used to prepare this report. The primary objectives of this flight were to retrieve the Japanese Space Flyer Unit (JSFU) and deploy and retrieve the Office of Aeronautics and Space Technology-Flyer (OAST-Flyer). Secondary objectives were to perform the operations of the Shuttle Solar Backscatter Ultraviolet (SSBUV/A) experiment, Shuttle Laser Altimeter (SLA)/get-Away Special (GAS) payload, Physiological and Anatomical Rodent Experiment/National Institutes of Health-Cells (STL/NIH-C) experiment, Protein Crystal Growth-Single Locker Thermal Enclosure System (PCG-STES) experiment, Commercial Protein Crystal Growth (CPCG) payload and perform two extravehicular activities (EVA's) to demonstrate International Space Station Alpha (ISSA) assembly techniques). Appendix B provides the definition of acronyms and abbreviations used throughout the report. All times during the flight are given in Greenwich mean time (GMT) and mission elapsed time (MET).

Fricke, Robert W., Jr.↗
NASA NTRS2004

The monitoring system for vibratory disturbance detection in microgravity environment aboard the international space station

Scientists in the Office of Life and Microgravity Sciences and Applications within the Microgravity Research Division oversee studies in important physical, chemical, and biological processes in microgravity environment. Research is conducted in microgravity environment because of the beneficial results that come about for experiments. When research is done in normal gravity, scientists are limited to results that are affected by the gravity of Earth. Microgravity provides an environment where solid, liquid, and gas can be observed in a natural state of free fall and where many different variables are eliminated. One challenge that NASA faces is that space flight opportunities need to be used effectively and efficiently in order to ensure that some of the most scientifically promising research is conducted. Different vibratory sources are continually active aboard the International Space Station (ISS). Some of the vibratory sources include crew exercise, experiment setup, machinery startup (life support fans, pumps, freezer/compressor, centrifuge), thruster firings, and some unknown events. The Space Acceleration Measurement System (SAMs), which acts as the hardware and carefully positioned aboard the ISS, along with the Microgravity Environment Monitoring System MEMS), which acts as the software and is located here at NASA Glenn, are used to detect these vibratory sources aboard the ISS and recognize them as disturbances. The various vibratory disturbances can sometimes be harmful to the scientists different research projects. Some vibratory disturbances are recognized by the MEMS's database and some are not. Mainly, the unknown events that occur aboard the International Space Station are the ones of major concern. To better aid in the research experiments, the unknown events are identified and verified as unknown events. Features, such as frequency, acceleration level, time and date of recognition of the new patterns are stored in an Excel database. My task is to carefully synthesize frequency and acceleration patterns of unknown events within the Excel database into a new file to determine whether or not certain information that is received i s considered a real vibratory source. Once considered as a vibratory source, further analysis is carried out. The resulting information is used to retrain the MEMS to recognize them as known patterns. These different vibratory disturbances are being constantly monitored to observe if, in any way, the disturbances have an effect on the microgravity environment that research experiments are exposed to. If the disturbance has little or no effect on the experiments, then research is continued. However, if the disturbance is harmful to the experiment, scientists act accordingly by either minimizing the source or terminating the research and neither NASA's time nor money is wasted.

Laster, Rachel M.↗
NASA NTRS1976

Long duration exposure facility - A multipurpose free-flying experiment carrier

The Long Duration Exposure Facility (LDEF) is being developed to accommodate, using the Shuttle, a class of technology, science, and applications experiments which do not require a sophisticated or dedicated satellite. The LDEF is a simple reusable structure approximately 4.3 m in diameter and 9 m in length. The basic LDEF consists of a structural framework whose cross section is a 12-sided regular polygon. A facility description is provided, taking into account the structure, aspects of attitude stabilization, the experiment trays, the experiment exposure control canister, the environment monitoring system, and Shuttle bay environment measurements. Missions and questions of experiment selection are discussed, giving attention to orbits, dynamic motions, a space debris damage experiment, thermal coating experiments, the solar cells and arrays experiment, and the active optical components experiment.

Kinard, W. H.↗
NASA NTRS1981

Distributed control of large space structures

Theoretical developments and the results of laboratory experiments are treated as they apply to active attitude and vibration control, as well as static shape control. Modern control theory was employed throughout as the method for obtaining estimation and control laws.

Schaechter, D. B.↗
NASA NTRS1984

Space adaptation syndrome: Incidence and operational implications for the space transportation system program

Better methods for the prediction, prevention, and treatment of the space adaptation syndome (SAS) were developed. A systematic, long range program of operationally oriented data collection on all individuals flying space shuttle missions was initiated. Preflight activities include the use of a motion experience questionnaire, laboratory tests of susceptibility to motion sickness induced by Coriolis stimuli and determinations of antimotion sickness drug efficacy and side effects. During flight, each crewmember is required to provide a daily report of symptom status, use of medications, and other vestibular related sensations. Additional data are obtained postflight. During the first nine shuttle missions, the reported incidence of SAS has been48%. Self-induced head motions and unusual visual orientation attitudes appear to be the principal triggering stimuli. Antimotion sickness medication, was of limited therapeutic value. Complete recovery from symptoms occurred by mission day three or four. Also of relevance is the lack of a statistically significant correlation between the ground based Coriolis test and SAS. The episodes of SAS have resulted in no impact to shuttle mission objectives and, no significant impact to mission timelines.

Homick, J. L.↗
NASA NTRS1988

Biochemical assays on plasminogen activators and hormones from kidney sources

Investigations were established for the purpose of analyzing the conditioned media from human embryonic kidney cell subpopulations separated in space by electrophoresis. This data is based on the experiments performed on STS-8 on the continuous flow electrophoresis system. The primary biological activity that was analyzed was plasminogen activator activity, but some assays for erythropoeitin and human granulocyte colony stimulating activity were also performed. It is concluded that a battery of assays are required to completely define the plasminogen activator profile of a conditioned media from cell culture. Each type of assay measures different parts of the mixture and are influenced by different parameters. The functional role of each assay is given along with an indication of which combination of assays are required to answer specific questions. With this type of information it is possible by combinations of assays with mathematical analysis to pinpoint a specific component of the system.

Barlow, Grant H.↗
NASA NTRS1990

Development and approach to low-frequency microgravity isolation systems

The low-gravity environment provided by space flight has afforded the science community a unique arena for the study of fundamental and technological sciences. However, the dynamic environment observed on space shuttle flights and predicted for Space Station Freedom has complicated the analysis of prior microgravity experiments and prompted concern for the viability of proposed space experiments requiring long-term, low-gravity environments. Thus, isolation systems capable of providing significant improvements to this random environment are being developed. The design constraints imposed by acceleration-sensitive, microgravity experiment payloads in the unique environment of space and a theoretical background for active isolation are discussed. A design is presented for a six-degree-of-freedom, active, inertial isolation system based on the baseline relative and inertial isolation techniques described.

Grodsinsky, Carlos M.↗
NASA NTRS1990

Experimental demonstration of active vibration control for flexible structures

Active vibration control of flexible structures for future space missions is addressed. Three experiments that successfully demonstrate control of flexible structures are described. The first is the pendulum experiment. The structure is a 5-m compound pendulum and was designed as an end-to-end test bed for a linear proof mass actuator and its supporting electronics. Experimental results are shown for a maximum-entropy/optimal-projection controller designed to achieve 5 percent damping in the first two pendulum modes. The second experiment was based upon the Harris Multi-Hex prototype experiment (MHPE) apparatus. This is a large optical reflector structure comprising a seven-panel array and supporting truss which typifies a number of generic characteristics of large space systems. The third experiment involved control design and implementation for the ACES structure at NASA Marshall Space Flight Center. The authors conclude with some remarks on the lessons learned from conducting these experiments.

Phillips, Douglas J.↗
NASA NTRS1992

Research objectives, opportunities, and facilities for microgravity science

Microgravity Science in the U.S.A. involves research in fluids science, combustion science, materials science, biotechnology, and fundamental physics. The purpose is to achieve a thorough understanding of the effects of gravitational body forces on physical phenomena relevant to those disciplines. This includes the study of phenomena which are usually overwhelmed by the presence of gravitational body forces and, therefore, chiefly manifested when gravitational forces are weak. In the pragmatic sense, the research involves gravity level as an experimental parameter. Calendar year 1992 is a landmark year for research opportunities in low earth orbit for Microgravity Science. For the first time ever, three Spacelab flights will fly in a single year: IML-1 was launched on January 22; USML-1 was launched on June 25; and, in September, SL-J will be launched. A separate flight involving two cargo bay carriers, USMP-1, will be launched in October. From the beginning of 1993 up to and including the Space Station era (1997), nine flights involving either Spacelab or USMP carriers will be flown. This will be augmented by a number of middeck payloads and get away specials flying on various flights. All of this activity sets the stage for experimentation on Space Station Freedom. Beginning in 1997, experiments in Microgravity Science will be conducted on the Space Station. Facilities for doing experiments in protein crystal growth, solidification, and biotechnology will all be available. These will be joined by middeck-class payloads and the microgravity glove box for conducting additional experiments. In 1998, a new generation protein crystal growth facility and a facility for conducting combustion research will arrive. A fluids science facility and additional capability for conducting research in solidification, as well as an ability to handle small payloads on a quick response basis, will be added in 1999. The year 2000 will see upgrades in the protein crystal growth and fluids science facilities. From the beginning of 1997 to the fall of 1999 (the 'man-tended capability' era), there will be two or three utilization flights per year. Plans call for operations in Microgravity Science during utilization flights and between utilization flights. Experiments conducted during utilization flights will characteristically require crew interaction, short duration, and less sensitivity to perturbations in the acceleration environment. Operations between utilization flights will involve experiments that can be controlled remotely and/or can be automated. Typically, the experiments will require long times and a pristine environment. Beyond the fall of 1999 (the 'permanently-manned capability' era), some payloads will require crew interaction; others will be automated and will make use of telescience.

Bayuzick, Robert J.↗
NASA NTRS1994

Participation in the scientific activities of the Waves in Space Plasma (WISP) project

This is the Final Report for Contract NAG5-1925, that consisted of experiment design, for possible use by the space science mission called WISP (Waves in Space Plasma). This mission is under study by the Canadian Space Agency and by NASA. Two WISP configurations are contemplated, under the name of BICEPS: one is called BOLAS, and the other WISPRS. Both these configurations are meant to perform bistatic sounding of the ionosphere, at a height close to F(sub 2) H(sub max) (about 350 Km), with a pair of satellites, either tethered or in free flight. Investigation A (with Y.L. Alpert as P.I.) addresses the subject of parametric decay effects, expected to arise in a magnetoplasma under the influence of high-intensity HF fields. Criteria were formulated that could be used in searching for parametric instabilities and of electric fields in the ionosphere and magnetosphere, by in-situ satellites, such as the BICEPS Pair. Investigation B (with M.D.Grossi as P.I.) addressed the bistatic measurement, by the BICEPS pair,of ionospheric features, such as large-scale and small-scale disturbances, travelling ionospheric disturbances, electron density irregularities, spread-F phenomena, etc. These measurements by BICEPS could be correlated with the waveform distortion and degradation experienced by microwave links from geosynchronous height to ground, such as the ACTS satellite, expected to radiate pulses as short as 1 nanosecond in the band 20 to 30 GHz. These links are transionospheric and propagate e.m. waves in the volume of the ionosphere where BICEPS operates. It will be possible, therefore, to correlate the two classes of measurements, and learn the causative mechanisms that are responsible for the time-spread and frequency-spread nature of communications waveforms at microwave, in geosynchronous height to ground paths.

Alpert, Yakov L.↗