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NASA NTRS2002

STS-112 Crew Interviews: Melroy

Pamela A. Melroy USAF Pilot, is seen during a prelaunch interview. She gives a brief overview of the STS-112 mission which is to install the S1 truss on the International Space Station. She also gives some specific details about the structural design of the S1 truss. Pamela Melroy is also the Internal EVA (IV) coordinator for this mission. She talks about her responsibilities as the IV which are to direct the spacewalkers back into the Airlock after the S1 is installed. A detailed description about the goals of EVA (2) and EVA (3) are also given by Melroy.

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NASA NTRS2002

STS-112 Crew Interviews - Wolf

STS-112 Mission Specialist David Wolf is seen during this preflight interview, where he first answers questions on his career path and role models. Other questions cover mission goals, ISS (International Space Station) Expedition 5 spacecrew, crew training, the S1 Truss and its radiators, the MBS (Mobile Base Structure), his experience onboard Mir, and his EVAs (extravehicular activities) on the coming mission. The EVAs are the subject of several questions. Wolf discusses his crew members, and elsewhere discusses Pilot Pamela Melroy's role as an IV crew member during EVAs. In addition, Wolf answers questions on transfer operations, the SHIMMER experiment, and his thoughts on multinational crews and crew bonding.

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NASA NTRS2002

STS-112 Flight Day 4 Highlights

On the fourth day of STS-112, its crew (Jeffrey Ashby, Commander; Pamela Melroy, Pilot; David Wolf, Mission Specialist; Piers Sellers, Mission Specialist; Sandra Magnus, Mission Specialist; Fyodor Yurchikhin, Mission Specialist) onboard Atlantis and the Expedition 5 crew (Valery Korzun, Commander; Peggy Whitson, Flight Engineer; Sergei Treschev, Flight Engineer) onboard the International Space Station (ISS) are seen preparing for the installation of the S1 truss structure. Inside the Destiny Laboratory Module, Korzun and other crewmembers are seen as they busily prepare for the work of the day. Sellers dons an oxygen mask and uses an exercise machine in order to purge the nitrogen from his bloodstream, in preparation for an extravehicular activity (EVA). Whitson uses the ISS's Canadarm 2 robotic arm to grapple the S1 truss and remove it from Atlantis' payload bay, with the assistance of Magnus. Using the robotic arm, Whitson slowly maneuvers the 15 ton truss structure into alignment with its attachment point on the starboard side of the S0 truss structure, where the carefully orchestrated mating procedures take place. There is video footage of the entire truss being rotated and positioned by the arm, and ammonia tank assembly on the structure is visible, with Earth in the background. Following the completion of the second stage capture, the robotic arm is ungrappled from truss. Sellers and Wolf are shown exiting the the Quest airlock hatch to begin their EVA. They are shown performing a variety of tasks on the now attached S1 truss structure, including work on the Crew Equipment Translation Cart (CETA), the S-band Antenna Assembly, and umbilical cables that provide power and remote operation capability to cameras. During their EVA, they are shown using a foot platform on the robotic arm. Significant portions of their activities are shown from the vantage of helmet mounted video cameras. The video closes with a final shot of the ISS and its new S1 truss.

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NASA NTRS2002

STS-112 Flight Day 6 Highlights

On the sixth flight day of STS-112 (Atlantis crewmembers include Dave Wolf, Mission Specialists; Sandy Magnus, Mission Specialists; Pam Melroy, Pilot; Jeff Ashby, Commander; Piers Sellers, Mission Specialists; Fyodor Yurchikhin, Mission Specialists), Wolf and Sellers are seen preparing for an EVA (extravehicular activity) during which they will service the ISS (International Space Station) to which Atlantis is docked. This will be the 45th EVA in support of ISS assembly and maintenance and the 20th conducted from the ISS. While the astronauts prepare, video footage is shown of the Sahara desert, over which the ISS is passing in a track that will take it over North Africa and the Mediterranean Sea. During the EVA, the External Television Camera Group will be brought out of the station and attached to the station. As the astronauts work, their helmet mounted cameras provide excellent footage of the ISS with the Shuttle docked at the Destiny Laboratory Module. Multiple shots of the station show several modules including Destiny, Quest, Unity and Zarya, as well as Canadarm 2 and Atlantis. The video closes with a wide angle shot of the ISS.

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NASA NTRS2002

STS-113 Post Flight Presentation

The STS-113 post-flight presentation begins with a view of Mission Specialists Michael E. Lopez-Alegria and John B. Herrington getting suited for the space mission. The STS-113 crew consists of: Commander James D. Wetherbee, Pilot Paul Lockhart, Mission Specialists Michael Lopez-Alegria and John Herrington. Cosmonauts Valery Korzun, and Sergei Treschev, and astronaut Peggy Whitson who are all members of the expedition five crew, and Commander Kenneth Bowersox, Flight Engineers Nikolai Budarin and Donald Pettit, members of Expedition Six. The main goal of this mission is to take Expedition Six up to the International Space Station and Return Expedition Five to the Earth. The second objective is to install the P(1) Truss segment. Three hours prior to launch, the crew of Expedition Six along with James Wetherbee, Paul Lockhart, Michael Lopez-Alegria and John Herrington are shown walking to an astrovan, which takes them to the launch pad. The actual liftoff is presented. Three Extravehicular Activities (EVA)'s are performed on this mission. Michael Lopez-Alegria and John Herrington are shown performing EVA 1 and EVA 2 which include making connections between the P1 and S(0) Truss segments, and installing fluid jumpers. A panoramic view of the ISS with the Earth in the background is shown. The grand ceremony of the crew exchange is presented. The astronauts performing everyday duties such as brushing teeth, washing hair, sleeping, and eating pistachio nuts are shown. The actual landing of the Space Shuttle is presented.

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NASA NTRS2003

Analysis of a Radiation Model of the Shuttle Space Suit

The extravehicular activity (EVA) required to assemble the International Space Station (ISS) will take approximately 1500 hours with 400 hours of EVA per year in operations and maintenance. With the Space Station at an inclination of 51.6 deg the radiation environment is highly variable with solar activity being of great concern. Thus, it is important to study the dose gradients about the body during an EVA to help determine the cancer risk associated with the different environments the ISS will encounter. In this paper we are concerned only with the trapped radiation (electrons and protons). Two different scenarios are looked at: the first is the quiet geomagnetic periods in low Earth orbit (LEO) and the second is during a large solar particle event in the deep space environment. This study includes a description of how the space suit's computer aided design (CAD) model was developed along with a description of the human model. Also included is a brief description of the transport codes used to determine the total integrated dose at several locations within the body. Finally, the results of the transport codes when applied to the space suit and human model and a brief description of the results are presented.

Anderson, Brooke M.↗
NASA NTRS2003

Quantifying Astronaut Tasks: Robotic Technology and Future Space Suit Design

The primary aim of this research effort was to advance the current understanding of astronauts' capabilities and limitations in space-suited EVA by developing models of the constitutive and compatibility relations of a space suit, based on experimental data gained from human test subjects as well as a 12 degree-of-freedom human-sized robot, and utilizing these fundamental relations to estimate a human factors performance metric for space suited EVA work. The three specific objectives are to: 1) Compile a detailed database of torques required to bend the joints of a space suit, using realistic, multi- joint human motions. 2) Develop a mathematical model of the constitutive relations between space suit joint torques and joint angular positions, based on experimental data and compare other investigators' physics-based models to experimental data. 3) Estimate the work envelope of a space suited astronaut, using the constitutive and compatibility relations of the space suit. The body of work that makes up this report includes experimentation, empirical and physics-based modeling, and model applications. A detailed space suit joint torque-angle database was compiled with a novel experimental approach that used space-suited human test subjects to generate realistic, multi-joint motions and an instrumented robot to measure the torques required to accomplish these motions in a space suit. Based on the experimental data, a mathematical model is developed to predict joint torque from the joint angle history. Two physics-based models of pressurized fabric cylinder bending are compared to experimental data, yielding design insights. The mathematical model is applied to EVA operations in an inverse kinematic analysis coupled to the space suit model to calculate the volume in which space-suited astronauts can work with their hands, demonstrating that operational human factors metrics can be predicted from fundamental space suit information.

Newman, Dava↗
NASA NTRS1990

Advanced Robotics for In-Space Vehicle Processing

An analysis of spaceborne vehicle processing is described. Generic crew-EVA tasks are presented for a specific vehicle, the orbital maneuvering vehicle (OMV), with general implications to other on-orbit vehicles. The OMV is examined with respect to both servicing and maintenance. Crew-EVA activities are presented by task and mapped to a common set of generic crew-EVA primitives to identify high-demand areas for telerobot services. Similarly, a set of telerobot primitives is presented that can be used to model telerobot actions for alternative telerobot reference configurations. The telerobot primitives are tied to technologies and used for composting telerobot operations for an automated refueling scenario. Telerobotics technology issues and design accomodation guidelines (hooks and scars) for the Space Station Freedom are described.

Smith, Jeffrey H.↗
NASA NTRS2003

STS-114 Crew Training Clip

The crew of Space Shuttle Atlantis on STS-114 is seen conducting several training exercises in preparation for their mission. The crew consists of Commander Eileen Collins, Pilot James Kelly, and Mission Specialists Soichi Noguchi and Stephen Robinson. With them are Yuri Malenchenko, Sergei Moschenko, and Edward Lu, the intended Expedition 7 crew of the International Space Station (ISS). During extravehicular activity (EVA) training in the virtual reality (VR) laboratory, crew members explore the exterior of the ISS, seen on a monitor. Suiting up with VR equipment is also shown. More EVA training takes place in the Neutral Buoyancy Laboratory (NBL). Here the astronauts are suited up for the NBL pool, and lowered into the water on a platform. After a crew photo session, the astronauts are seated in the Motion Base Simulator in their flight suits. The simulator is shown rocking side-to-side. The crew also hears a hands-on explanation of EVA preparations in the ISS airlock, and practices emergency egress from the CCT, a simulator shaped like an orbiter.

Source record↗
NASA NTRS2003

Radiation Protection Studies of International Space Station Extravehicular Activity Space Suits

This publication describes recent investigations that evaluate radiation shielding characteristics of NASA's and the Russian Space Agency's space suits. The introduction describes the suits and presents goals of several experiments performed with them. The first chapter provides background information about the dynamic radiation environment experienced at ISS and summarized radiation health and protection requirements for activities in low Earth orbit. Supporting studies report the development and application of a computer model of the EMU space suit and the difficulty of shielding EVA crewmembers from high-energy reentrant electrons, a previously unevaluated component of the space radiation environment. Chapters 2 through 6 describe experiments that evaluate the space suits' radiation shielding characteristics. Chapter 7 describes a study of the potential radiological health impact on EVA crewmembers of two virtually unexamined environmental sources of high-energy electrons-reentrant trapped electrons and atmospheric albedo or "splash" electrons. The radiological consequences of those sources have not been evaluated previously and, under closer scrutiny. A detailed computational model of the shielding distribution provided by components of the NASA astronauts' EMU is being developed for exposure evaluation studies. The model is introduced in Chapters 8 and 9 and used in Chapter 10 to investigate how trapped particle anisotropy impacts female organ doses during EVA. Chapter 11 presents a review of issues related to estimating skin cancer risk form space radiation. The final chapter contains conclusions about the protective qualities of the suit brought to light form these studies, as well as recommendations for future operational radiation protection.

Cucinotta, Francis A.↗
NASA NTRS2003

Proton and Electron Threshold Energy Measurements for Extravehicular Activity Space Suits

Construction of ISS will require more than 1000 hours of EVA. Outside of ISS during EVA, astronauts and cosmonauts are likely to be exposed to a large fluence of electrons and protons. Development of radiation protection guidelines requires the determination of the minimum energy of electrons and protons that penetrate the suits at various locations. Measurements of the water-equivalent thickness of both US. and Russian EVA suits were obtained by performing CT scans. Specific regions of interest of the suits were further evaluated using a differential range shift technique. This technique involved measuring thickness ionization curves for 6-MeV electron and 155-MeV proton beams with ionization chambers using a constant source-to-detector distance. The thicknesses were obtained by stacking polystyrene slabs immediately upstream of the detector. The thicknesses of the 50% ionizations relative to the maximum ionizations were determined. The detectors were then placed within the suit and the stack thickness adjusted until the 50% ionization was reestablished. The difference in thickness between the 50% thicknesses was then used with standard range-energy tables to determine the threshold energy for penetration. This report provides a detailed description of the experimental arrangement and results.

Moyers, M. F.↗
NASA NTRS2003

A Comparison of Model Calculation and Measurement of Absorbed Dose for Proton Irradiation

With the increase in the amount of time spent EVA that is necessary to complete the construction and subsequent maintenance of ISS, it will become increasingly important for ground support personnel to accurately characterize the radiation exposures incurred by EVA crewmembers. Since exposure measurements cannot be taken within the organs of interest, it is necessary to estimate these exposures by calculation. To validate the methods and tools used to develop these estimates, it is necessary to model experiments performed in a controlled environment. This work is such an effort. A human phantom was outfitted with detector equipment and then placed in American EMU and Orlan-M EVA space suits. The suited phantom was irradiated at the LLUPTF with proton beams of known energies. Absorbed dose measurements were made by the spaceflight operational dosimetrist from JSC at multiple sites in the skin, eye, brain, stomach, and small intestine locations in the phantom. These exposures are then modeled using the BRYNTRN radiation transport code developed at the NASA Langley Research Center, and the CAM (computerized anatomical male) human geometry model of Billings and Yucker. Comparisons of absorbed dose calculations with measurements show excellent agreement. This suggests that there is reason to be confident in the ability of both the transport code and the human body model to estimate proton exposure in ground-based laboratory experiments.

Zapp, N.↗
NASA NTRS2003

Summary and Recommendations for Future Work

The safety of astronauts is the primary concern of all space missions. Space radiation has been identified as a major concern for ISS, and minimizing radiation risks during EVA is a principle component of NASA s radiation protection program. The space suit plays a critical role in shielding astronauts from EVA radiation exposures. In cooperation with the JSC Extravehicular Activity Project Office, and the Space Radiation Health Project Office, the NASA EMU and RSA Orlan space suits were taken to the LLUPTF for a series of measurements with proton and electron beams to simulate exposures during EVA operations. Additional tests with material layouts of the EMU suit sleeve were made in collaboration with NASA LaRC at the LBNL 88-inch cyclotron and at the Brookhaven National Laboratory Alternating Gradient Synchrotron.

Cucinotta, Francis A.↗
NASA NTRS2002

Vestibular convergence patterns in vestibular nuclei neurons of alert primates

Sensory signal convergence is a fundamental and important aspect of brain function. Such convergence may often involve complex multidimensional interactions as those proposed for the processing of otolith and semicircular canal (SCC) information for the detection of translational head movements and the effective discrimination from physically congruent gravity signals. In the present study, we have examined the responses of primate rostral vestibular nuclei (VN) neurons that do not exhibit any eye movement-related activity using 0.5-Hz translational and three-dimensional (3D) rotational motion. Three distinct neural populations were identified. Approximately one-fourth of the cells exclusively encoded rotational movements (canal-only neurons) and were unresponsive to translation. The canal-only central neurons encoded head rotation in SCC coordinates, exhibited little orthogonal canal convergence, and were characterized with significantly higher sensitivities to rotation as compared to primary SCC afferents. Another fourth of the neurons modulated their firing rates during translation (otolith-only cells). During rotations, these neurons only responded when the axis of rotation was earth-horizontal and the head was changing orientation relative to gravity. The remaining one-half of VN neurons were sensitive to both rotations and translations (otolith + canal neurons). Unlike primary otolith afferents, however, central neurons often exhibited significant spatiotemporal (noncosine) tuning properties and a wide variety of response dynamics to translation. To characterize the pattern of SCC inputs to otolith + canal neurons, their rotational maximum sensitivity vectors were computed using exclusively responses during earth-vertical axis rotations (EVA). Maximum sensitivity vectors were distributed throughout the 3D space, suggesting strong convergence from multiple SCCs. These neurons were also tested with earth-horizontal axis rotations (EHA), which would activate both vertical canals and otolith organs. However, the recorded responses could not be predicted from a linear combination of EVA rotational and translational responses. In contrast, one-third of the neurons responded similarly during EVA and EHA rotations, although a significant response modulation was present during translation. Thus this subpopulation of otolith + canal cells, which included neurons with either high- or low-pass dynamics to translation, appear to selectively ignore the component of otolith-selective activation that is due to changes in the orientation of the head relative to gravity. Thus contrary to primary otolith afferents and otolith-only central neurons that respond equivalently to tilts relative to gravity and translational movements, approximately one-third of the otolith + canal cells seem to encode a true estimate of the translational component of the imposed passive head and body movement.

Non-NASA Center↗
NASA NTRS2002

The effect of simulated weightlessness on hypobaric decompression sickness

BACKGROUND: A discrepancy exists between the incidence of ground-based decompression sickness (DCS) during simulated extravehicular activity (EVA) at hypobaric space suit pressure (20-40%) and crewmember reports during actual EVA (zero reports). This could be due to the effect of gravity during ground-based DCS studies. HYPOTHESIS: At EVA suit pressures of 29.6 kPa (4.3 psia), there is no difference in the incidence of hypobaric DCS between a control group and group exposed to simulated weightlessness (supine body position). METHODS: Male subjects were exposed to a hypobaric pressure of 29.6 kPa (4.3 psi) for up to 4 h. The control group (n = 26) pre-oxygenated for 60 min (first 10 min exercising) before hypobaric exposure and walking around in the altitude chamber. The test group (n = 39) remained supine for a 3 h prior to and during the 60-min pre-oxygenation (also including exercise) and at hypobaric pressure. DCS symptoms and venous gas emboli (VGE) at hypobaric pressure were registered. RESULTS: DCS occurred in 42% in the control and in 44% in simulated weightlessness group (n.s.). The mean time for DCS to develop was 112 min (SD +/- 61) and 123 min (+/- 67), respectively. VGE occurred in 81% of the control group subjects and in 51% of the simulated weightlessness subjects (p = 0.02), while severe VGE occurred in 58% and 33%, respectively (p = 0.08). VGE started after 113 min (+/- 43) in the control and after 76 min (+/- 64) in the simulated weightlessness group. CONCLUSIONS: No difference in incidence of DCS was shown between control and simulated weightlessness conditions. VGE occurred more frequently during the control condition with bubble-releasing arm and leg movements.

NASA Discipline Environmental Health↗
NASA NTRS1997

Evaluation of cardiac rhythm disturbances during extravehicular activity

This study represents the first systematic evaluation of dysrhythmias before, during, and after spaceflight including extravehicular activity (EVA). The data, based on 7 Shuttle crew members, revealed a nonsignificant decrease in ventricular and supraventricular ectopy during EVA, suggesting that the incidence of dysrhythmias is no greater during EVA than with any other phase of a mission or preflight.

NASA Program Flight↗
NASA NTRS2005

STS-114: Discovery Q and A with Joint Crew on ISS

Commander Sergei Krikalev and Flight Engineer John Phillips of the Expedition 11 crew, along with the STS-114 Discovery crewmembers are shown on the International Space Station, answering questions from the news media. Eileen Collins, Commander summarizes the untold story of this mission and she also describes what re-entry is like. Steven Robinson, Mission Specialist talks about Extravehicular Activity (EVA) and the gap fillers used to replace missing tiles on the Space Shuttle Discovery. John Phillips describes the equipment coming off the space station and how this equipment will make the International Space Station more efficient. Soichi Noguchi, Mission Specialist answers questions about EVA 1, 2, and 3 and Collins talks about what impressed her most during these EVA's.

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NASA NTRS2003

STS-114: Crew Training Clip from JSC

STS-114 Discovery crew is shown in various training exercises at Johnson Space Center. The crew consists of Eileen Collins, Commander; James Kelley, Pilot; Charles Camarda, Mission Specialist; Wendy Lawrence, Mission Specialist; Soichi Noguchi, Mission Specialist; Steve Robinson, Mission Specialist; and Andy Thomas, Mission Specialist. The exercises include: 1) EVA training in the VR lab; 2) Neutral Buoyancy Laboratory (NBL) EVA Training; 3) Walk to Motion Base Simulator; 4) EVA Preparations in ISS Airlock; and 7) Emergency Egress from Crew Compartment Trainer (CCT). A crew photo session is also presented. Footage of The Space Shuttle Atlantis inside the Kennedy Space Center Vehicle Assembly Building (VAB) after its demating from the Solid Rocket Booster and External Tank is shown. The video ends with techniques for inspecting and repairing Thermal Protection System tiles, a video of external tank production at the Michoud Assembly Facility (MAF) and redesign of the foam from the bipod ramp at Michoud Assembly Facility (MAF).

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