Extravehicular activity operations concepts under communication latency and bandwidth constraints

The establishment of sustained human presence on the Moon for science and exploration combines the design, integration, and operation challenges experienced from both the short Apollo lunar missions and the build-up and sustained crew operations of the International Space Station (ISS). With the goal of establishing a lunar Outpost on the Moon to extend human presence, pursue scientific activities, use the Moon to prepare for future human missions to Mars, and expand Earth’s economic sphere, a change in how both the Apollo and ISS Programs were planned and executed is required for this new international lunar exploration program. Since the Vision for Space Exploration (VSE) was released in 2004, NASA, in conjunction with international space agencies, industry, and academia, has continued to define and refine plans for sustained and affordable robotic and human exploration of the Moon and beyond. One area NASA is developing that can significantly change how systems required for sustained human presence are designed and integrated, as well as potentially break our reliance on Earth supplied logistics, is In-Situ Resource Utilization (ISRU). ISRU, also known “living off the land”, involves the extraction and processing of local resources into useful products. In particular, the ability to make propellants, life support consumables, fuel cell reagents, and radiation shielding can significantly reduce the cost, mass, and risk of sustained human activities beyond Earth. The ability to modify the lunar landscape for safer landing, transfer of payloads from the lander to an outpost, dust generation mitigation, and infrastructure placement and buildup are also extremely important for longterm lunar operations. Because ISRU hardware and systems have never been demonstrated before, NASA is examining how these capabilities can be added into mission designs and plans such that lunar mission success is currently not relying on these capabilities, but that the systems developed are flexible enough to incorporate the capabilities once they have been demonstrated. With this in mind, the ISRU Project within the Exploration Technology Development Program (ETDP) has initiated development and testing of hardware and systems in three main focus areas: (1) Regolith Excavation, Handling and Material Transportation; (2) Oxygen Extraction from Regolith; and (3) ISRU Precursor Activities. To minimize cost and ensure that ISRU technologies, systems, and functions are integrated properly into the Outpost, technology development efforts are being coordinated with other ETDP development areas such as Surface Mobility, Surface Power, Life Support, EVA, and Propulsion, as well as outside government agencies, industry, academia, and International Partners to the maximum extent possible to leverage funding and increase commonality of hardware at the Outpost. Lastly, laboratory and field system-level tests and demonstrations will be performed as often as possible to demonstrate improvements in: Capabilities (ex. 1 ISRU Project Manager for ETDP, EP, and AIAA Member 2 Chief, Applied Science Division, KT-D-2, and AIAA Member 3 ISRU Lead for Excavation, MS 77-5, and AIAA Member 4 Deputy for ISRU Development Support, VP33, and AIAA Member AIAA SPACE 2008 Conference & Exposition 9 11 September 2008, San Diego, California AIAA 2008-7853 Copyright © 2008 by the American Institute of Aeronautics and Astronautics, Inc. The U.S. Government has a royalty-free license to exercise all rights under the copyright claimed herein for Governmental purposes. All other rights are reserved by the copyright owner. American Institute of Aeronautics and Astronautics 2 digging deeper); Performance (ex. lower power); and Duration (ex. more autonomy or more robustness), as well as form the partnerships with industry and International Partners that will be needed once actual Outpost flight hardware development and deployment begins. This paper will provide the status of work performed to date within the NASA ISRU Project with respect to technology and system development and field demonstration activities, as well as the current strategy to implement ISRU in future robotic and human lunar exploration missions.

Modeling a 15-min extravehicular activity prebreathe protocol using NASA׳s exploration atmosphere (56.5 kPa/34% O2)

Planetary protection for humans in space: Mars and the Moon

Maintaining astronaut health during space travel is paramount for further human exploration of the solar system beyond Earth's orbit. Of concern are potential dysregulations in immunity, which could increase the likelihood of cancer and latent viral reactivation. Natural killer (NK) cells are critical effectors of the innate immune system, and their function and phenotype are important to immunosurveillance of nascent tumors and latent viral infections. We compared changes in NK cell phenotype and function in eight crew members who completed an ~6-mo mission to the International Space Station (ISS) with healthy controls who remained on Earth. Assessments were made before (180 and 60 days before launch), during [flight day + 90 days (FD+90) and 1 day before return (R-1)], and after the mission (at R+0, R+18, R+33, and R+66). These samples, plus an additional in-flight sample (FD+180), were collected from a crew member who spent 340 days (~1 yr) on the ISS. NK cell cytotoxic activity (NKCA) against K562 leukemia targets in vitro was reduced by ~50% at FD+90 in ISS crew but not controls. This decrease was more pronounced in "rookie" compared with "veteran" crew members. The ~1-yr mission crew member did not show declines in NKCA against K562 until late in the mission (R-1 and R+0). NK cell numbers, expression of activating and inhibitory receptors, target cell binding, and expression and degranulation of perforin and granzyme B were unaltered with spaceflight. Similarly, when we exposed an immortalized NK cell line (NK-92) to sera collected at different mission time points (before, during, and after flight), there was no effect on NKCA. This is the first study to report impaired NK cell function during long-duration space travel. Countermeasures may be needed to mitigate immune system impairment in exploration class mission crew during long-duration spaceflight missions. NEW & NOTEWORTHY Immune system impairment may inhibit future human space exploration missions to Mars. Natural killer (NK) cells are key components of immunity and vital for tumor surveillance and the prevention of latent virus reactivation. We report that NK cell function is impaired in astronauts during an ~6-mo orbital space mission compared with preflight levels and ground-based controls. Declines in NK cell function were more marked in first-time "rookie" fliers. Countermeasures are needed to preserve NK cell-mediated immunity during spaceflight.

We are preparing to return humans to the Moon and setting the stage for exploration to Mars and beyond. However, it is unclear if long missions outside of Low-Earth Orbit (LEO) can be accomplished with acceptable risk. The central objective of our project, the Earth-Moon-Mars Radiation Exposure Module (EMMREM), is to develop and validate a numerical module for completely characterizing time-dependent radiation exposure in the Earth-Moon-Mars and Interplanetary space environments. EMMREM will provide the ability to predict radiation exposure on the surface or atmosphere of Earth, on the Moon, Mars, and in interplanetary space between Earth and Mars. EMMREM is being designed for broad use by researchers to predict radiation exposure by integrating over almost any incident particle distribution from interplanetary space. EMMREM is being developed using contemporary state-of-the-art particle radiation models. Beyond this, it will have the capability to incorporate new and improving models, as they become available, to give continually improved estimates of radiation hazards and effects. EMMREM will be comprehensively validated using direct and contemporaneous measurements near Earth, at the Moon and Mars to significantly reduce uncertainties in radiation exposure predictions. EMMREM will characterize the extremes, statistics, and variations over time of radiation exposure caused by solar energetic particles and cosmic rays. The results of EMMREM will improve risk assessment models so that future human exploration missions can be adequately planned for. This makes highly relevant to NASA's Vision for Space Exploration and the Living With a Star Programs.

The search for evidence of extant and extinct life on Mars is of big interest for future robotic and human exploration missions. The properties and characteristics of evaporites such as gypsum make them an easily accessible target in the search for biosignatures of extraterrestrial life. On Earth, a diverse microbial community inhabits gypsum in modern brines. These microbes are easily entombed within gypsum due to its fast precipitation. Studies of primary lower gypsum deposits, accumulated in the Mediterranean Basin during the Messinian salinity crisis (5.97 – 5.33 Ma), revealed a well-preserved and prominent archive of diverse microbial life. Similar archives might exist on Mars considering the desiccation of large bodies of water there, representing a promising target for exploring the possibility of life on Mars. The recent imaging mapping and analysis done by orbiters and rovers on the surface of Mars led to the discovery of abundant gypsum and evaporite minerals suggesting the evaporation of large lakes and lacustrine systems and as the surface of Mars dried out, hypersaline lakes would have filled the ancient lake system. A similar scenario happened on Earth when thick layers of gypsum were deposited during the Messinian salinity crisis when the Mediterranean was turned into the youngest salt giant in Earth’s history.Previous chemical and molecular laser mass spectrometry analyses done on microfossils preserved in different rock records showed these instruments’ ability to detect biosignatures related to ancient life. In this study, we successfully investigated the chemical composition of fossil filaments interpreted to be benthic microbial assemblages dominated by chemotrophic sulfide-oxidizing bacteria, sulfate-reducing bacteria, and planktonic cyanobacteria. This study demonstrated the efficiency of a miniaturized next-generation Laser based Mass Spectrometer (LMS) designed for future space explorations in the detection of microbial chemical biosignatures trapped in Messinian gypsum, shading light to the potential application to the search for life on Mars.    Literature Natalicchio, M., Birgel, D., Dela Pierre, F., Ziegenbalg, S., Hoffmann-Sell, L., Gier, S., & Peckmann, J. (2022). Messinian bottom-grown selenitic gypsum: An archive of microbial life. Geobiology, 20, 3– 21. https://doi.org/10.1111/gbi.12464.Bayles, M., Belasco, B.C., Breda, A.J., Cahill, C.B., Da Silva, A.Z., Regan, M.J., Jr., Schlamp, N.K., Slagle, M.P. and Baxter, B.K. (2020). The Haloarchaea of Great Salt Lake as Models for Potential Extant Life on Mars. In Extremophiles as Astrobiological Models (eds J. Seckbach and H. Stan-Lotter). https://doi.org/10.1002/9781119593096.ch4.Lukmanov, RA., Tulej, M., Ligterink, NFW., et al. ( 2021). Chemical identification of microfossils from the 1.88-Ga Gunflint chert: Towards empirical biosignatures using laser ablation ionization mass spectrometer. Journal of Chemometrics, 35 ( 10):e3370. doi:10.1002/cem.3370.

System studies have shown that large deployable aerodynamic decelerators such as the Adaptive Deployable Entry and Placement Technology (ADEPT) concept can revolutionize future robotic and human exploration missions involving atmospheric entry, descent and landing by significantly reducing the maximum heating rate, total heat load, and deceleration loads experienced by the spacecraft during entry [1-3]. ADEPT and the Hypersonic Inflatable Aerodynamic Decelerator (HIAD) [4] share the approach of stowing the entry system in the shroud of the launch vehicle and deploying it to a much larger diameter prior to entry. The ADEPT concept provides a low ballistic coefficient for planetary entry by employing an umbrella-like deployable structure consisting of ribs, struts and a fabric cover that form an aerodynamic decelerator capable of undergoing hypersonic flight. The ADEPT "skin" is a 3-D woven carbon cloth that serves as a thermal protection system (TPS) and as a structural surface that transfers aerodynamic forces to the underlying ribs [5]. This paper focuses on design activities associated with integrating ADEPT components (cloth, ribs, struts and mechanisms) into a system that can function across all configurations and environments of a typical mission concept: stowed during launch, in-space deployment, entry, descent, parachute deployment and separation from the landing payload. The baseline structures and mechanisms were selected via trade studies conducted during the summer and fall of 2012. They are now being incorporated into the design of a ground test article (GTA) that will be fabricated in 2013. It will be used to evaluate retention of the stowed configuration in a launch environment, mechanism operation for release, deployment and locking, and static strength of the deployed decelerator. Of particular interest are the carbon cloth interfaces, underlying hot structure, (Advanced Carbon- Carbon ribs) and other structural components (nose cap, struts, and main body) designed to withstand the pressure and extremely high heating experienced during planetary entry.

Digital Beamforming has gained significant importance in radar applications in the past years. It helps improve radar performance while reducing mass and power. Improving these figures becomes even more important for space applications. The Space Exploration Synthetic Aperture Radar (SESAR) is a novel P-band (70 cm wavelength) radar instrument developed for planetary applications that will enable surface and near-subsurface measurements of Solar System planetary bodies. The radar will measure full polarimetry at meter-scale resolution, and perform beam steering through programmable digital beamforming architecture. The data obtained with SESAR will provide key information on buried ice and water signatures that can facilitate the design of future human and robotic exploration missions. In this paper we describe SESAR’s large antenna array, the sub-systems integration process, and the different environmental testing activities performed to the overall system in order to raise the Technology Readiness Level (TRL) for its future inclusion in a space-proven system.

Future human spaceflight missions will face the complex challenge of performing human extravehicular activity (EVA) beyond the low Earth orbit (LEO) environment. Astronauts will become increasingly isolated from Earth-based mission support and thus will rely heavily on their own decision-making capabilities and onboard tools to accomplish proposed EVA mission objectives. To better address time delay communication issues, EVA characters, e.g. flight controllers, astronauts, etc., and their respective work practices and roles need to be better characterized and understood. This paper presents the results of a study examining the EVA work domain and the personnel that operate within it. The goal is to characterize current and historical roles of ground support, intravehicular (IV) crew and EV crew, their communication patterns and information needs. This work provides a description of EVA operations and identifies issues to be used as a basis for future investigation.

The nuclear thermal rocket (NTR) provides a unique propulsion capability to planners/designers of future human exploration missions to the Moon and Mars. In addition to its high specific impulse (approximately 850-1000 s) and engine thrust-to-weight ratio (approximately 3-10), the NTR can also be configured as a 'dual mode' system capable of generating electrical power for spacecraft environmental systems, communications, and enhanced stage operations (e.g., refrigeration for long-term liquid hydrogen storage). At present the Nuclear Propulsion Office (NPO) is examining a variety of mission applications for the NTR ranging from an expendable, single-burn, trans-lunar injection (TLI) stage for NASA's First Lunar Outpost (FLO) mission to all propulsive, multiburn, NTR-powered spacecraft supporting a 'split cargo-piloted sprint' Mars mission architecture. Each application results in a particular set of requirements in areas such as the number of engines and their respective thrust levels, restart capability, fuel operating temperature and lifetime, cryofluid storage, and stage size. Two solid core NTR concepts are examined -- one based on NERVA (Nuclear Engine for Rocket Vehicle Application) derivative reactor (NDR) technology, and a second concept which utilizes a ternary carbide 'twisted ribbon' fuel form developed by the Commonwealth of Independent States (CIS). The NDR and CIS concepts have an established technology database involving significant nuclear testing at or near representative operating conditions. Integrated systems and mission studies indicate that clusters of two to four 15 to 25 klbf NDR or CIS engines are sufficient for most of the lunar and Mars mission scenarios currently under consideration. This paper provides descriptions and performance characteristics for the NDR and CIS concepts, summarizes NASA's First Lunar Outpost and Mars mission scenarios, and describes characteristics for representative cargo and piloted vehicles compatible with a reference 240 t-class heavy lift launch vehicle (HLLV) and smaller 120 t HLLV option. Attractive performance characteristics and high-leverage technologies associated with both the engine and stage are identified, and supporting parametric sensitivity data is provided. The potential for commonality of engine and stage components to satisfy a broad range of lunar and Mars missions is also discussed.

This paper describes the results of a recent (July-August 2010 and July 2011) planetary surface traverse planning experiment. The purpose of this experiment was to gather data relevant to robotically repositioning surface assets used for planetary surface exploration. This is a scenario currently being considered for future human exploration missions to the Moon and Mars. The specific scenario selected was a robotic traverse on the lunar surface from an outpost at Shackleton Crater to the Malapert Massif. As these are exploration scenarios, the route will not have been previously traversed and the only pre-traverse data sets available will be remote (orbital) observations. Devon Island was selected as an analog location where a traverse route of significant length could be planned and then traveled. During the first half of 2010, a team of engineers and scientists who had never been to Devon Island used remote sensing data comparable to that which is likely to be available for the Malapert region (eg., 2-meter/pixel imagery, 10-meter interval topographic maps and associated digital elevation models, etc.) to plan a 17-kilometer (km) traverse. Surface-level imagery data was then gathered on-site that was provided to the planning team. This team then assessed whether the route was actually traversable or not. Lessons learned during the 2010 experiment were then used in a second experiment in 2011 for which a much longer traverse (85 km) was planned and additional surface-level imagery different from that gathered in 2010 was obtained for a comparative analysis. This paper will describe the route planning techniques used, the data sets available to the route planners and the lessons learned from the two traverses planned and carried out on Devon Island.

NASA’s Hubble Space Telescope was designed for supportability by Space Shuttle astronauts performing extravehicular activities (EVAs), or spacewalks, to service, maintain, repair, and upgrade the telescope. Through three successful servicing missions to date, EVA processes have been developed by applying a series of important lessons learned. These lessons learned are also applicable to many other future human spaceflight and robotic missions, such as International Space Station, satellite retrieval and servicing, and long-duration spaceflight. HST has become NASA’s pathfinder for observatories, EVA development, and EVA mission execution.

NASA's eXploration Systems and Habitation (X-Hab) Academic Innovation Challenge

Human exploration and development of space is aimed at opening the space frontier by exploring, using, and enabling the development of space and expanding the human experience into the far reaches of space. This includes increasing human knowledge of nature’s processes using the space environment, exploring and settling the solar system, achieving routine space travel, and enriching life on Earth through people living and working in space. NASA’s Mars robotic explorations and the International Space Station provide extensive experience, research and technology (R&T), and infrastructure for other envisioned programs in support of human exploration and development of space. The missions to Moon by United States, Russia, China, India, and Japan have provided valuable data for the Moon. In addition, NASA has studied the development of a lunar habitat and human mission to Mars as possible future missions. These missions face common challenges of travel to these planets and for the survival of humans on the surface of the planets. With the human Mars mission being the first to such a distant planet, advanced technologies will be required to enable the mission and to provide cost effective and safer approaches. The R&T areas considered important for future human mission include advanced human support, renewable resources and utilization of planetary resources, space transportation, automation and robotics, space power, information processing and communications systems, sensors, and instruments.

To provide for crewmember well-being on future exploration missions, understanding coping strategies that International Space Station (ISS) crewmembers adopt to mitigate the inherent stress of long-duration confinement is important. A recent retrospective survey of flown astronauts found that the most commonly reported psychologically enriching aspects of spaceflight had to do with their perceptions of Earth. ISS crewmembers photograph Earth both volitionally and in response to requests from Crew Earth Observations (CEO) scientists. Automatically recorded data from the camera can be used to test hypotheses about factors correlated with self-initiated crewmember photography. The present study used these objective in-flight data to investigate the nature of voluntary photographic activity. We examined the distribution of photographs with respect to time, crew, and subject matter. We determined whether the frequency fluctuated in conjunction with major mission events such as vehicle dockings and extravehicular activities (EVAs, or spacewalks), relative to the norm for the relevant crew. We also examined the influence of geographic and temporal patterns on frequency of Earth photography activities. We tested the hypotheses that there would be peak photography intensity over locations of personal interest, as well as on weekends.Of nearly 200,000 photographs taken on eight ISS expeditions, 84.5% were crew-initiated. Once a crewmember went to the window for a CEO request, he or she was more likely to take photographs for his or her own interest. Fewer self-initiated images were taken during and immediately preceding major station events. Crewmembers were more likely to take self-initiated images during periods when they had more free time. Analysis indicated some phasing in patterns of photography during the course of a mission, although it did not suggest that psychological functioning was lower during the third quarter of confinement (i.e., no third-quarter effect was found). Earth photography is a self-initiated positive activity of possible importance for salutogenesis (increase in well-being) of astronauts on long-duration missions. Scientific requests for photography through CEO play an important role in facilitating crew-initiated photography. Consideration should be given to developing substitute activities for crewmembers in future exploration missions where there will not be the opportunity to look at Earth, such as on long-duration transits to Mars.KeywordsBehavioral HealthInternational Space StationSpace ShuttleGENMOD ProcedureGeneral AvailabilityThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.