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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 271 records · Page 15
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NASA NTRS2019

Sextant Navigation on the International Space Station: A Human Space Exploration Demo

Astronauts on board the International Space Station (ISS) tested a hand-held sextant to demonstrate potential use on future human exploration missions such as Orion and Gateway. The investigation, designed to aid in the development of emergency navigation methods for future crewed spacecraft, took place from June-December 2018. A sextant provides manual capability to perform star/planet-limb sightings and estimate vehicle state during loss of communication or other contingencies. Its simplicity and independence from primary systems make it useful as an emergency survival backup or confirming measurement source. The concept of using a sextant has heritage in Gemini, Apollo, and Skylab. This paper discusses the instrument selection, flight certification, crew training, product development, experiment execution, and data analysis. Preflight training consisted of a hands-on session with the instrument and practice in a Cupola mock-up with star field projector dome. The experiment itself consisted of several sessions with sextant sightings in the ISS Cupola module by two crew members. Sightings were taken on star pairs, star/moon limb, and moon diameter. The sessions were designed to demonstrate star identification and acquisition, sighting stability, accuracy, and lunar sights. Results are presented which demonstrate sightings within the accuracy goal of 60 arcseconds, even in the presence of window refraction effects and minimal crew training. The crew members provided valuable feedback on sighting products and microgravity stability techniques.

Exploration↗
NASA NTRS1987

Inflight combined vertical and lateral space vehicular accelerations - Human tolerances

Human tolerance studies related to inflight rolling (tumbling) accelerations are discussed, with emphasis on the need to provide data on combinations of Gy, as experienced during an anomalous roll aboard Gemini VIII during which upper body (-) Gz forces and lower body (+) Gz forces were experienced. The study also points to the need to provide data on tolerances to (+) or (-) Gy combined with (-) Gz, in addition to the lowered tolerances to Gy and Gz accelerations experienced by those adapted to microgravity. It is noted that such data can be used to establish limits on spacecraft acceleration maneuvering specifications.

Mohler, S. R.↗
NASA NTRS1971

Experiments D004 and D007: Celestial radiometry and space object radiometry

Two interferometer spectrometers and a multichannel spectroradiometer were used as sensing instruments during the Gemini 5 and 7 missions. The selection of the instruments and of the particular detectors in the instruments was based upon the spectral bands to be investigated in each flight and upon the nature of the intended measurements. The instrument characteristics were a compromise among optimization for a particular type of measurement, a need for a broad selection of spectral information, and performance and other pertinent characteristics of the spacecraft. Data were collected on earth background, sky background, rocket exhaust plumes, celestial bodies, man made objects in space, weather phenomena, and spectral calibrations.

Lovett, J.↗
NASA NTRS1971

Experiment Do14: Ultrahigh and very high frequency polarization

The measurement of inhomogeneities in the electron content along the orbital paths of Gemini 8 and Gemini 9 missions was not accomplished because the tracking information was not available. The use of ultrahigh frequency radio transmission was the primary factor in the successful removal of a very high frequency Faraday rotation ambiguity; but, as was expected, this was not very useful for fine-scale polarization studies. Ionosonde data were useful in the computation of the slab thickness at the closest point of approach of the spacecraft.

Ellis, R. E.↗
NASA NTRS1971

Experiment S029: Earth-Moon libration regions photography

Eleven photographs were taken of the L sub 4 earth-moon libration region during the Gemini 12 mission. The objective was to investigate the possible existence of clouds or particles of dust orbiting the earth in the L sub 4 region by the use of photographic techniques. No identifiable data were found in the first sequence of five photographs. Star field images could be recognized in two photographs of the second sequence of pictures. A light flare, of unknown source but possibly caused by light refraction from the window of the spacecraft, was recorded in both pictures. A reconstructed star field region (as photographed) is shown Isodensitraces of the two recognizable star fields were made; however, no conclusive results were obtained.

Morris, E. C.↗
NASA NTRS1971

Experiment S007: Cloud top spectrometry

During the Gemini 5 mission, 26 spectrographic observations on various cloud types were obtained using the oxygen A band (7600 A). An example of the types of spectrum and photograph involved represents a cloud in the intertropical convergence zone. Densitometer traces of the spectra of three types of clouds (high, medium, and low) are shown. It was apparent qualitatively that radiation transmission in the oxygen band for a high cloud was much greater than that for a low cloud. The results proved the feasibility of cloud altitude measurements from a spacecraft by this method.

Saiedy, F.↗
NASA NTRS1971

Experiment D012: Astronaut maneuvering unit

All astronaut maneuvering unit systems used during the Gemini 9 mission were in an acceptable condition for flight when the evaluation was terminated. Some difficulty was experienced with reception of the voice signal by the command pilot. All of the donning provisions are apparently practical in the orbital environment; however, the donning activities were more difficult to perform than had been experienced in the one-g and zero-g training exercises. Lighting was marginal because of the failure of one adapter floodlight and one penlight. The crewmembers reported a tendency for the extravehicular activity pilot and any loose equipment to move outward from the earth relative to the spacecraft. This tendency affected activities at a work station and maneuvering in an extravehicular environment.

Vanschaik, P. N.↗
NASA NTRS2013

The Mission Accessible Near-Earth Objects Survey (MANOS)

Near‐Earth objects (NEOs) are essential to understanding the origin of the Solar System. Their relatively small sizes and complex dynamical histories make them excellent laboratories for studying ongoing Solar System processes. The proximity of NEOs to Earth makes them favorable targets for space missions. In addition, knowledge of their physical properties is crucial for impact hazard assessment. However, in spite of their importance to science, exploration, and planetary defense, a representative sample of physical characteristics for sub‐km NEOs does not exist. Here we present the Mission Accessible Near‐Earth Objects Survey (MANOS), a multi‐year survey of subkm NEOs that will provide a large, uniform catalog of physical properties (light curves + colors + spectra + astrometry), representing a 100‐fold increase over the current level of NEO knowledge within this size range. This survey will ultimately characterize more than 300 mission‐accessible NEOs across the visible and near‐infrared ranges using telescopes in both the northern and southern hemispheres. MANOS has been awarded 24 nights per semester for the next three years on NOAO facilities including Gemini North and South, the Kitt Peak Mayall 4m, and the SOAR 4m. Additional telescopic assets available to our team include facilities at Lowell Observatory, the University of Hawaii 2.2m, NASA's IRTF, and the Magellan 6.5m telescopes. Our focus on sub‐km sizes and mission accessibility (dv < 7 km/s) is a novel approach to physical characterization studies and is possible through a regular cadence of observations designed to access newly discovered NEOs within days or weeks of first detection before they fade beyond observational limits. The resulting comprehensive catalog will inform global properties of the NEO population, advance scientific understanding of NEOs, produce essential data for robotic and spacecraft exploration, and develop a critical knowledge base to address the risk of NEO impacts. We intend to conduct this survey with complete transparency, publicly sharing our target lists and survey progress. We invite collaborative uses for these data as a way to broaden the scientific impact of this survey.

Abell, Paul↗
NASA NTRS1974

Apollo experience report: Food systems

Development, delivery, and use of food systems in support of the Apollo 7 to 14 missions are discussed. Changes in design criteria for this unique program as mission requirements varied are traced from the baseline system that was established before the completion of the Gemini Program. Problems and progress in subsystem management, material selection, food packaging, development of new food items, menu design, and food-consumption methods under zero-gravity conditions are described. The effectiveness of various approaches in meeting food system objectives of providing flight crews with safe, nutritious, easy to prepare, and highly acceptable foods is considered. Nutritional quality and adequacy in maintaining crew health are discussed in relation to the establishment of nutritional criteria for future missions. Technological advances that have resulted from the design of separate food systems for the command module, the lunar module, The Mobile Quarantine Facility, and the Lunar Receiving Laboratory are presented for application to future manned spacecraft and to unique populations in earthbound situations.

Smith, M. C., Jr.↗
NASA NTRS1971

Experiment S009: Nuclear Emulsion

The first exposure on a spacecraft of a nuclear emulsion apparatus designed to collect 1000 high quality tracks of heavy nuclei under a negligible thickness of matter (0.07 g/sq cm) is described. The cosmic ray detector consisted of a stack of nuclear emulsions that were designed to register at least 400 heavy nuclei tracks for each 10 hours of useful exposure. The spacecraft had to be oriented in a heads-up attitude during the 10-hour period to eliminate atmospheric albedo particles. The results are as follows: (1) a definite odd-even effect, with low abundances for elements of atomic number 7, 9, and 11; (2) a ratio O/C approximately 0.9; (3) Ne/C, Mg/C, and Si/C ratios between 0.2 and 0.3; (4) an abundance gap in the region 15 less than or equal to Z less than or equal to 19; and (5) a ratio (20 less than or equal to Z less than or equal to 28)/C 0.2, with a large concentration at Z = 26. These results are indicative that successful exposures of nuclear emulsions were obtained on the Gemini 11 mission.

Odell, F. W.↗
NASA NTRS1971

Experiment T001: Entry communication on the Gemini 3 mission

Water addition to the Gemini 3 exhaust plasma was studied to determine its effectiveness in the establishment of communication links during the entry portion of the flight. Attenuation levels were measured with and without water injection at uhf frequencies of 230.4 and 296.8 megahertz and at the C-band frequency of 5690 megahertz. Ultrahigh frequency signals that had been blacked out were restored to significant levels, during early portions of the water-injection sequence, by the high flow rate injection. The C-band signal was enhanced by medium and high flow rate injections during the latter portion of the injection period. The uhf signal recovered during water injection resulted in an antenna pattern that was beamed in the radial direction of injection from the spacecraft. Postflight analysis showed that the uhf recovery data were consistent with injection-penetration theory.

Schroeder, L. C.↗
NASA NTRS1972

Determination of pilot and vehicle describing functions from the Gemini 10 mission

Three types of manual control maneuvers conducted during the Gemini-10 mission have been analyzed in order to measure and document the describing function of the pilot, the vehicle and the pilot-vehicle combination during an actual space mission. Measurements made from the data records of the reentry maneuver (a single axis control task) indicate that the pilot's control behavior changes during critical portions of the reentry. Measurements made of the deorbit maneuver and of a terminal phase initiation maneuver (three axis tasks) show that the pilot assigns priorities to the separate axes and controls them differently. His control technique is also influenced by the magnitude of the thrust disturbance present during the maneuvers. The results for all three types of maneuvers show that the pilot adapts to the nonlinear spacecraft control system in such a way that the combined pilot-vehicle dynamics take the form of the linear crossover model.

Edwards, F. G.↗
NASA NTRS2004

Manned Spacecraft Landing and Recovery

As recent history has tragically demonstrated, a successful space mission is not complete until the crew has safely returned to earth and has been successfully recovered. It is noted that a safe return to earth does not guarantee a successful recovery. The focus of this presentation will be a discussion of the ground operation assets involved in a successful recovery. The author's experience in land and water-based recovery of crewed vehicles and flight hardware at Kennedy Space Center (KSC), Edwards Air Force Base, international landing sites, and the Atlantic Ocean provides for some unique insight into this topic. He has participated in many aspects of Space Shuttle landing and recovery operations including activation of Transatlantic Abort Landing (TAL) sites and Emergency Landing Sites (ELS) as an Operations Test Director, execution of post landing convoy operations as an Orbiter Move Director, Operations Test Director, and Landing and Recovery Director, and recovery of solid rocket boosters, frustum and their parachutes 140 miles offshore in a wide range of sea states as a Retrieval Diver/Engineer. The recovery operations for the Mercury, Gemini, and Apollo were similar from a landing and recovery perspective in th t they all were capsules with limited "flying" capability and had a planned End of Mission (EOM) in an ocean with a descent slowed by parachutes. The general process was to deploy swim teams via helicopters to prepare the capsule for recovery and assist with crew extraction when required. The capsule was then hoisted onto the deck of a naval vessel. This approach required the extensive use and deployment of military assets to support the primary landing zone as well as alternate and contingency locations. The Russian Soyuz capsule also has limited "flying" capability; however, the planned EOM is terrestrial. In addition to use of parachutes to slow the reentry descent, soft-landing rockets on the bottom of the vehicle are employed to cushion the landing. The recovery forces are deployed via helicopters and the capsule is transported by a specialized all-terrain vehicle. The Space Shuttle Orbiter landing and recovery process is considerably different. The added lift capability and maneuverability allow the Orbiter to land at an exact location/runway for a nominal EOM. This allows for a timely response of recovery/contingency rescue forces, centralized staging of personnel and equipment, and assured access by ground vehicles. The well defined landing zone also provides for far more options when selecting landing sites for EOM and emergency returns and the relatively large cross-range capability increases the number of landing opportunities at the preferred sites.

Hammel, Don↗
NASA NTRS2000

The Mission Transcript Collection: U.S. Human Spaceflight Missions from Mercury Redstone 3 to Apollo 17

Aboard every U.S. piloted spacecraft, from Mercury through Apollo, NASA installed tape recorders that captured nearly every word spoken by the astronauts during their history-making flights into space. For the first time ever, NASA has digitally scanned all of the transcripts made from both the onboard tapes and those tape recordings made on the ground from the air-to-ground transmissions and placed them on this two CD-ROM set. Gathered in this special collection are 80 transcripts totaling nearly 45,000 pages of text that cover every US human spaceflight from the first human Mercury mission through the last lunar landing flight of Apollo 17. Users of this CD will note that the quantity and type of transcripts made for each mission vary. For example, the Mercury flights each had one transcript whereas the Gemini missions produced several. Starting with the Gemini flights, NASA produced a Public Affairs Office (PAO) commentary version, as well as at least one "technical" air-to-ground transcript version, per mission. Most of the Apollo missions produced four transcripts per flight. These included the onboard voice data recorder transcripts made from the Data Storage Equipment (DSE) on the Command Module (CM), and the Data Storage Electronics Assembly (DSEA) onboard the Lunar Module (LM), in addition to the PAO commentary and air-to-ground technical transcripts. The CD set includes an index listing each transcript file by name. Some of the transcripts include a detailed explanation of their contents and how they were made. Also included in this collection is a listing of all the original air-to-ground audiotapes housed in NASA's archives from which many of these transcripts were made. We hope you find this collection of transcripts interesting and useful.

Source record↗
NASA NTRS2009

Validity of the Aluminum Equivalent Approximation in Space Radiation Shielding

The origin of the aluminum equivalent shield approximation in space radiation analysis can be traced back to its roots in the early years of the NASA space programs (Mercury, Gemini and Apollo) wherein the primary radiobiological concern was the intense sources of ionizing radiation causing short term effects which was thought to jeopardize the safety of the crew and hence the mission. Herein, it is shown that the aluminum equivalent shield approximation, although reasonably well suited for that time period and to the application for which it was developed, is of questionable usefulness to the radiobiological concerns of routine space operations of the 21 st century which will include long stays onboard the International Space Station (ISS) and perhaps the moon. This is especially true for a risk based protection system, as appears imminent for deep space exploration where the long-term effects of Galactic Cosmic Ray (GCR) exposure is of primary concern. The present analysis demonstrates that sufficiently large errors in the interior particle environment of a spacecraft result from the use of the aluminum equivalent approximation, and such approximations should be avoided in future astronaut risk estimates. In this study, the aluminum equivalent approximation is evaluated as a means for estimating the particle environment within a spacecraft structure induced by the GCR radiation field. For comparison, the two extremes of the GCR environment, the 1977 solar minimum and the 2001 solar maximum, are considered. These environments are coupled to the Langley Research Center (LaRC) deterministic ionized particle transport code High charge (Z) and Energy TRaNsport (HZETRN), which propagates the GCR spectra for elements with charges (Z) in the range I <= Z <= 28 (H -- Ni) and secondary neutrons through selected target materials. The coupling of the GCR extremes to HZETRN allows for the examination of the induced environment within the interior' of an idealized spacecraft as approximated by a spherical shell shield, and the effects of the aluminum equivalent approximation for a good polymeric shield material such as genetic polyethylene (PE). The shield thickness is represented by a 25 g/cm spherical shell. Although one could imagine the progression to greater thickness, the current range will be sufficient to evaluate the qualitative usefulness of the aluminum equivalent approximation. Upon establishing the inaccuracies of the aluminum equivalent approximation through numerical simulations of the GCR radiation field attenuation for PE and aluminum equivalent PE spherical shells, we Anther present results for a limited set of commercially available, hydrogen rich, multifunctional polymeric constituents to assess the effect of the aluminum equivalent approximation on their radiation attenuation response as compared to the generic PE.

Badavi, Francis F.↗
NASA NTRS2019

Challenges and Opportunities of International Cooperation for Safety & Mission Assurance (SMA) on the European Service Module (ESM) of the Orion Program

ESA is providing the ESM to NASA for the Orion Program in accordance with the Implementing Arrangement (IA) established between the two Agencies in 2012. This IA is a barter agreement, in which ESA provides Service Module vehicles for the first two flights of Orion in exchange for two servicing missions to the ISS. This arrangement has provided opportunities and challenges to both communities. It represents an important opportunity for ESA to build on its experience in the development and operations of ATV and play an active role in the development and flight of a manned space vehicle. This paper will explore some of the unique aspects of this arrangement as it affects Safety & Mission Assurance (SMA).The assessment of ESM compliance with applicable safety requirements is the responsibility of the Joint Safety and Engineering Review Panel (JSERP). The JSERP has two features that are relatively unique amongst NASA safety panels. First, NASA Engineering and SMA organizations co-chair this Panel. Previously, Safety has chaired, with Engineering as a member of the Panel. Inclusion of Engineering as a co-chair has offered greater leverage within the technical community. Second, the JSERP includes a second set of co-chairs from ESA Engineering and ESA Product Assurance and Safety (PA/S) organizations. This recognizes the international arrangement as one of partnership.Another source of both opportunity and challenge is the differing experience base of ESA and NASA. NASA has decades of experience in manned spaceflight, dating back to the Mercury program and following through Gemini, Apollo, Apollo-Soyuz, Skylab, Shuttle and the International Space Station. The risk posture for manned missions is much more rigorous than for unmanned missions. ESA brings a wealth of knowledge as well, with their flights of Ariane and Automated Transfer Vehicle (ATV), development and operation of the Columbus module on ISS, and satellite programs. The result is that both parties have developed paradigms related to risk and failure that contribute to ESM discussions.Orion represents humanity's first venture beyond Low-Earth Orbit (LEO) in over fifty years. Much of that experience is captured in program documents, but first-hand knowledge is limited to a few spaceflight veterans. Missions to LEO have offered the opportunity of direct, near-instantaneous communications and assistance, and the ability to return to Earth within a matter of hours in case of emergency. Outward-bound missions do not have these features and will require a more autonomous spacecraft with attendant safety-related issues.This paper will explore these and other challenges as we approach the flight of the first Orion vehicle.

Ciancone, Michael L.↗
NASA NTRS2017

Tracking Historical NASA EVA Training: Lifetime Surveillance of Astronaut Health (LSAH) Development of the EVA Suit Exposure Tracker (EVA SET)

During a spacewalk, designated as extravehicular activity (EVA), an astronaut ventures from the protective environment of the spacecraft into the vacuum of space. EVAs are among the most challenging tasks during a mission, as they are complex and place the astronaut in a highly stressful environment dependent on the spacesuit for survival. Due to the complexity of EVA, NASA has conducted various training programs on Earth to mimic the environment of space and to practice maneuvers in a more controlled and forgiving environment. However, rewards offset the risks of EVA, as some of the greatest accomplishments in the space program were accomplished during EVA, such as the Apollo moonwalks and the Hubble Space Telescope repair missions. Water has become the environment of choice for EVA training on Earth, using neutral buoyancy as a substitute for microgravity. During EVA training, an astronaut wears a modified version of the spacesuit adapted for working in water. This high fidelity suit allows the astronaut to move in the water while performing tasks on full-sized mockups of space vehicles, telescopes, and satellites. During the early Gemini missions, several EVA objectives were much more difficult than planned and required additional time. Later missions demonstrated that "complex (EVA) tasks were feasible when restraints maintained body position and underwater simulation training ensured a high success probability".1,2 EVA training has evolved from controlling body positioning to perform basic tasks to complex maintenance of the Hubble Space Telescope and construction of the International Space Station (ISS). Today, preparation is centered at special facilities built specifically for EVA training, such as the Neutral Buoyancy Laboratory (NBL) at NASA's Johnson Space Center ([JSC], Houston) and the Hydrolab at the Gagarin Cosmonaut Training Centre ([GCTC], Star City, outside Moscow). Underwater training for an EVA is also considered hazardous duty for NASA astronauts. This activity places astronauts at risk for decompression sickness and barotrauma as well as various musculoskeletal disorders from working in the spacesuit. The medical, operational and research communities over the years have requested access to EVA training data to better understand the risks. As a result of these requests, epidemiologists within the Lifetime Surveillance of Astronaut Health (LSAH) team have compiled records from numerous EVA training venues to quantify the exposure to EVA training. The EVA Suit Exposure Tracker (EVA SET) dataset is a compilation of ground-based training activities using the extravehicular mobility unit (EMU) in neutrally buoyant pools to enhance EVA performance on orbit. These data can be used by the current ISS program and future exploration missions by informing physicians, researchers, and operational personnel on the risks of EVA training in order that future suit and mission designs incorporate greater safety. The purpose of this technical report is to document briefly the various facilities where NASA astronauts have performed EVA training while describing in detail the EVA training records used to generate the EVA SET dataset.

Laughlin, Mitzi S.↗