Engineering topics
Uri, John J.
Publications and source records attributed to Uri, John J..
The International Space Station as a Research Laboratory: A View to 2010 and Beyond
Assembly of International Space Station (ISS) is expected to be complete in 2010, with operations planned to continue through at least 2016. As we move nearer to assembly complete, replanning activities by NASA and ISS International Partners have been completed and the final complement of research facilities on ISS is becoming more certain. This paper will review pans for facilities in the US On-orbit Segment of ISS, including contributions from International Partners, to provide a vision of the research capabilities that will be available starting in 2010. At present, in addition to research capabilities in the Russian segment, the United States Destiny research module houses nine research facilities or racks. These facilities include five multi-purpose EXPRESS racks, two Human Research Facility (HRF) racks, the Microgravity Science Glovebox (MSG), and the Minus Eighty-degree Laboratory Freezer for ISS (MELFI), enabling a wide range of exploration-related applied as well as basic research. In the coming years, additional racks will be launched to augment this robust capability: Combustion Integrated Rack (CIR), Fluids Integrated Rack (FIR), Window Observation Rack Facility (WORF), Microgravity Science Research Rack (MSRR), Muscle Atrophy Research Exercise System (MARES), additional EXPRESS racks and possibly a second MELFI. In addition, EXPRESS Logistics Carriers (ELC) will provide attach points for external payloads. The European Space Agency s Columbus module will contain five research racks and provide four external attach sites. The research racks are Biolab, European Physiology Module (EPM), Fluid Science Lab (FSL), European Drawer System (EDS) and European Transport Carrier (ETC). The Japanese Kibo elements will initially support three research racks, Ryutai for fluid science, Saibo for cell science, and Kobairo for materials research, as well as 10 attachment sites for external payloads. As we look ahead to assembly complete, these new facilities represent a threefold increase from the current research laboratory infrastructure on ISS. In addition, the increase in resident crew size will increase from three to six in 2009, will provide the long-term capacity for completing research on board ISS. Transportation to and from ISS for crew and cargo will be provided by a fleet of vehicles from the United States, Russia, ESA and Japan, including accommodations for thermally-conditioned cargo. The completed ISS will have robust research accommodations to support the multidisciplinary research objective of scientists worldwide.
A Year in the Life of International Space Station
The past twelve months (October 2005 to September 2006) have been among the busiest in the life of the International Space Station (ISS), both in terms of on-orbit operations as well as future planning, for both ISS systems and research. The Expedition 12 and 13 crews completed their missions successfully, carrying out research for Russia, the United States, Europe and Japan, and bringing continuous ISS occupancy to nearly six years. The European Space Agency's (ESA) first Long Duration Mission on ISS is underway, involving significant international research. The Expedition 14 crew completed its training and is embarking on its own 6-month mission with a full slate of international research. Future crews are in training for their respective assembly and research missions. Shuttle flights resumed after a 10-month hiatus, delivering new research facilities and resuming assembly of ISS. ESA's Columbus research module was delivered to the Kennedy Space Center, joining Japan's Kibo research module already there. Following preflight testing, the two modules will launch in 2007 and 2008, respectively, joining Destiny as ISS's research infrastructure. A revised ISS configuration and assembly sequence were endorsed by all the Partners, with a reduced number of Shuttle flights, but for the first time including plans for post-Shuttle ISS operations after 2010. The new plan will pose significant challenges to the ISS research community. As Europe and Japan build their on-orbit research infrastructure, and long-term plans become firmer, the next 12 months should prove to be equally challenging and exciting.
Five Years of NASA Research on ISS: A Continuing Saga
The first NASA experiments reached ISS in September 2000, a very modest beginning to what later became a more robust, diverse and overall highly successful research program, continuing essentially uninterrupted since March 2001. Along the way, several major challenges had to be overcome. First, there were delays in the initial construction of the station. Second, maintenance of the station exceeded earlier assumptions resulting in less crew time being available for research. Third, the lengthy interruption of Shuttle flights after the Columbia accident significantly, but temporarily, reduced the research traffic to and from ISS. And fourth, the Vision of Space Exploration as caused a refocusing of NASA's research efforts on ISS from a multi-disciplinary basic and applied science program to one dedicated to solving the critical questions to enable exploration missions. The principal factors that allowed these challenges to be overcome have been flexibility and cooperation. Flexibility on the part of the ISS Program to minimize impacts to research from delays and resource bottlenecks, flexibility on the part of researchers to adapt their research to changing environments, and flexibility to be able to use existing and planned facilities not only for their original basic science purpose but also for new applications. And cooperation not only between the ISS Program and the research community, but also among NASA and its International Partners to continually strive to optimize the research conducted aboard ISS. Once the challenges were overcome, the research program has been remarkably successful, with an expanding on-orbit capability. Over 80 investigations have been completed, many resulting in publications.
International Research on ISS - The Benefits of Working Together
International Space Station is the most complex multinational cooperative space endeavor in history. Interagency agreements define utilization accommodations and resources available to each partner. Based on these arrangements, the partners select and implement research to meet agency goals and objectives. But to optimize the limited resources available to utilization, cooperation among the partners is essential. This paper describes various avenues available for partner cooperation and provides specific examples to demonstrate the value of such cooperation to accelerate and enhance science return.
Research on International Space Station - Building a Partnership for the Future
As its name implies, the International Space Station is a platform where the research programs of 16 partner nations are conducted. While each partner pursues its own research priorities, cooperation and coordination of the various national and agency research programs occurs at multiple levels, from strategic through tactical planning to experiment operations. Since 2000, a significant number of experiments have been carried out in the Russian ISS utilization program, which consists of the Russian national program of fundamental and applied research in 11 research areas and international cooperative programs and contract activities. The US research program began with simple payloads in 2000 and was significantly expanded with the addition of the US Laboratory module Destiny in 2001, and its outfitting with seven research racks to date. The Canadian Space Agency (CSA), the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) have made use of international cooperative arrangements with both the US and Russia to implement a variety of investigations in diverse research areas, and in the case of ESA included the flights of crewmembers to ISS as part of Soyuz Science Missions. In the future, ESA and JAXA will add their own research modules, Columbus and Kibo, respectively, to expand research capabilities both inside and outside ISS. In the aftermath of the Columbia accident and the temporary grounding of the Space Shuttle fleet, all ISS logistics have relied on Russian Progress and Sopz vehicles. The Russian national program has continued as before the Shuttle accident, as have international cooperative programs and contract activities, both during long-duration expeditions and visiting taxi missions. In several instances, Russian international cooperative activities with JAXA and ESA have also involved the use of US facilities and crewmembers in successful truly multilateral efforts. The US research program was rapidly refocused after the Shuttle accident to rely on greatly reduced upmass, and for the first time in the ISS program, US research hardware was launched on Progress vehicles and returned with crews on Soyuz spacecraft. It is hoped that these small but significant steps in international cooperation will lead to even greater endeavors once the remaining research modules are added to ISS.
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. c2003 American Institute of Aeronautics and Astronautics. Published by Elsevier Science Ltd. All rights reserved.
Lessons Learned from Mir - A Payload Perspective
Among the principal objectives of the Phase 1 NASA/Mir program were for the United States to gain experience working with an international partner, to gain working experience in long-duration space flight, and to gain working experience in planning for and executing research on a long-duration space platform. The Phase 1 program was to provide to the US early experience prior to the construction and operation of the International Space Station (Phase 2 and 3). While it can be argued that Mir and ISS are different platforms and that programmatically Phase 1 and ISS are organized differently, it is also clear that many aspects of operating a long-duration research program are platform independent. This can be demonstrated by a review of lessons learned from Skylab, a US space station program of the mid-1970's, many of which were again "learned" on Mir and are being "learned" on ISS. Among these are optimum crew training strategies, on-orbit crew operations, ground support, medical operations and crew psychological support, and safety certification processes
Accomplishments in Bioastronautics Research Aboard International Space Station
The seventh long-duration expedition crew is currently in residence aboard International Space Station (ISS), continuing a permanent human presence in space that began in October 2000. During that time, expedition crews have been operators and subjects for 16 Human Life Sciences investigations, to gain a better understanding of the effects of long-duration space flight on the crew members and of the environment in which they live. Investigations have been conducted to study the radiation environment in the station as well as during extravehicular activity (EVA); bone demineralization and muscle deconditioning; changes in neuromuscular reflexes, muscle forces and postflight mobility; causes and possible treatment of postflight orthostatic intolerance; risk of developing kidney stones; changes in pulmonary function caused by long-duration flight as well as EVA; crew and crew-ground interactions; and changes in immune function. The experiment mix has included some conducted in flight aboard ISS as well as several which collected data only pre- and postflight. The conduct of these investigations has been facilitated by the Human Research Facility (HRF). HRF Rack 1 became the first research rack on ISS when it was installed in the US laboratory module Destiny in March 2001. The rack provides a core set of experiment hardware to support investigations, as well as power, data and commanding capability, and stowage. The second HRF rack, to complement the first with additional hardware and stowage capability, will be launched once Shuttle flights resume. Future years will see additional capability to conduct human research on ISS as International Partner modules and facility racks are added to ISS . Crew availability, both as a subject count and time, will remain a major challenge to maximizing the science return from the bioastronautics research program.
Research Progress and Accomplishments on ISS
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. The first research payloads arrived at ISS more than two years ago, and continuous science has been ongoing for more than one and a half years. During this time, the research capabilities have been tremendously increased, even as assembly of the overall platform continues. Despite significant challenges along the way, ISS continues to successfully support a large number of investigations in a variety of research disciplines. The results of some of the early investigations are reaching the publication stage. The near future looms with new challenges, but experience to date and dedicated efforts give reason to be optimistic that the challenges will be overcome and that new and greater successes will be added to past ones.
Changes in leg volume during microgravity simulation
Little published information exists regarding the magnitude and time course of cephalad fluid shift resulting from microgravity simulations. Six subjects were exposed to 150 min each at horizontal bed rest, 6-deg head-down tilt, and horizontal water immersion. Fluid shift was estimated by calculating leg volumes from eight serial girth measurements from groin to ankle before, during, and after exposure. Results were compared with data from the first 3 h of spacecraft. By the end of exposure, total leg volume for the six subjects decreased by 2.6 +/- 0.8 percent, 1.7 +/- 1.2 percent, and 4.0 +/- 1.6 percent for horizontal, head-down, and immersion, respectively. Changes had plateaued for horizontal and head-down and had slowed for immersion. Relatively more fluid was lost from the lower leg than the thigh for all three conditions, particularly head-down. During the first 3 h of spaceflight, total leg volume decreased by 8.6 percent, and relatively more fluid was lost from the thigh than the lower leg. The difference in volume changes in microgravity and simulated microgravity may be caused by the small transverse pressures still present in ground-based simulations and the extremely nonlinear compliance of tissue.
Acute leg volume changes in weightlessness and its simulation
Leg volume changes were studied in six subjects during 150 min of horizontal, 6 deg headdown tilt and supine immersion. Results were compared to previously obtained space flight data. It is found that, at equivalent study times, the magnitude of the leg volume changes during the simulations was less than one half that seen during space flight. Relative and absolute losses from the upper leg were greater during space flight, while relative losses were greater from the lower leg during simulations.
Oculomotor function during space flight and susceptibility to space motion sickness
Horizontal vestibulo-ocular reflex (VOR) and saccadic eye movements (SEM) were studied in 18 subjects before and during five Space Shuttle missions to evaluate the effects of weightlessness and correlations between results and susceptibility to and actual presence of space motion sickness (SMS). Active sinusoidal head oscillation was the stimulus for VOR tests with vision (VVOR), with eyes shaded (VOR-ES), and VOR suppression (VOR-S). Eye movements were recorded by electrooculography and head position by a potentiometer. No pathological nystagmus or other abnormal eye movements were seen. No significant in-flight changes were seen in the gain, phase shift or waveform of VVOR, VOR-ES or VOR-S. Statistically significant increases in saccadic latency and decreases in saccadic velocity were seen, with no change in saccadic accuracy. Preflight differences between SMS susceptible and nonsusceptible subjects were noted only in VOR-S, with less complete suppression in susceptible subjects, a finding also seen in flight. During flight, VVOR gain was significantly increased in three nonaffected subjects. Saccades of SMS-affected subjects showed increased latency and velocity and decreased accuracy compared to saccades of unaffected subjects.
Visual suppression of the vestibulo-ocular reflex during space flight
Visual suppression of the vestibulo-ocular reflex was studied in 16 subjects on 4 Space Shuttle missions. Eye movements were recorded by electro-oculography while subjects fixated a head mounted target during active sinusoidal head oscillation at 0.3 Hz. Adequacy of suppression was evaluated by the number of nystagmus beats, the mean amplitude of each beat, and the cumulative amplitude of nystagmus during two head oscillation cycles. Vestibulo-ocular reflex suppression was unaffected by space flight. Subjects with space motion sickness during flight had significantly more nystagmus beats than unaffected individuals. These susceptible subjects also tended to have more nystagmus beats before flight.
Studies of the horizontal vestibulo-ocular reflex in spaceflight
Changes in the vestibulo-ocular reflex (VOR) during space flight have been suspected of contributing to space motion sickness. The horizontal VOR was studied in nine subjects on two space shuttle missions. Active unpaced head oscillation at 0.3 Hz was used as the stimulus to examine the gain and phase of the VOR with and without visual input, as well as the visual suppression of the reflex. No statistically significant changes were noted inflight in the gains or phase shifts of the VOR during any test condition, or between space motion sickness susceptible and nonsusceptible populations. Although VOR suppression was unaffected by spaceflight, the space motion sickness-susceptible group tended to exhibit greater error in the suppression than the nonsusceptible group. It is concluded that at this stimulus frequency, VOR gain is unaffected by space-flight, and any minor individual changes do not seem to contribute to space motion sickness.
Saccadic eye movement during spaceflight
Saccadic eye movements were studied in six subjects during two Space Shuttle missions. Reaction time, peak velocity and accuracy of horizontal, visually-guided saccades were examined preflight, inflight and postflight. Conventional electro-oculography was used to record eye position, with the subjects responding to pseudo-randomly illuminated targets at 0 deg and + or - 10 deg and 20 deg visual angles. In all subjects, preflight measurements were within normal limits. Reaction time was significantly increased inflight, while peak velocity was significantly decreased. A tendency toward a greater proportion of hypometric saccades inflight was also noted. Possible explanations for these changes and possible correlations with space motion sickness are discussed.
Studies of the horizontal vestibulo-ocular reflex on STS 7 and 8
Unpaced voluntary horizontal head oscillation was used to study the Vestibulo-Ocular Reflex (VOR) on Shuttle flights STS 7 and 8. Ten subjects performed head oscillations at 0.33 Hz + or - 30 deg amplitude under the followng conditions: VVOR (visual VOR), eyes open and fixed on a stationary target; VOR-EC, with eyes closed and fixed on the same target in imagination; and VOR-S (VOR suppression), with eyes open and fixed on a head-synchronized target. Effects of weightlessness, flight phase, and Space Motion Sickness (SMS) on head oscillation characteristics were examined. A significant increase in head oscillation frequency was noted inflight in subjects free from SMS. In subjects susceptible to SMS, frequency was reduced during their Symptomatic period. The data also suggest that the amplitude and peak velocity of head oscillation were reduced early inflight. No significant changes were noted in reflex gain or phase in any of the test conditions; however, there was a suggestion of an increase in VVOR and VOR-ES gain early inflight in asymptomatic subjects. A significant difference in VOR-S was found between SMS susceptible and non-susceptible subjects. There is no evidence that any changes in VOR characteristics contributed to SMS.
Eye and head motion during head turns in spaceflight
Eye-head motion was studied pre-, in- and postflight during single voluntary head turns. A transient increase in vestibulo-ocular reflex (VOR) gain occurred early in the flight, but later trended toward normal. This increased gain was produced by a relative increase in eye counterrotation velocity. Asymmetries in gain with right and left turns also occurred, caused by asymmetries in eye counterrotation velocities. These findings were remarkably similar to those from Soviet primate studies using gaze fixation targets, except the human study trended more rapidly toward normal. These findings differ substantially from those measuring VOR gain by head oscillation, in which no significant changes were found inflight. No visual disturbances were noted in either test condition or in normal activities. These head turn studies are the only ones to date documenting any functional change in VOR in weightlessness.