Developing a crew time model for human exploration missions to Mars

The Stratospheric Aerosol and Gas Experiment III on the International Space Station (SAGE III/ISS) mission will provide the science community with high-vertical resolution and nearly global observations of ozone, aerosols, water vapor, nitrogen dioxide, and other trace gas species in the stratosphere and upper-troposphere. SAGE III/ISS measurements will extend the long term Stratospheric Aerosol Measurement (SAM) and SAGE data record begun in the 1970s. The multi-decadal SAGE ozone and aerosol data sets have undergone intense scrutiny and are considered the international standard for accuracy and stability. SAGE data have been used to monitor the effectiveness of the Montreal Protocol. Key objectives of the mission are to assess the state of the recovery in the distribution of ozone, to reestablish the aerosol measurements needed by both climate and ozone models, and to gain further insight into key processes contributing to ozone and aerosol variability. The space station mid-inclination orbit allows for a large range in latitude sampling and nearly continuous communications with payloads. The SAGE III instrument is the fifth in a series of instruments developed for monitoring atmospheric constituents with high vertical resolution. The SAGE III instrument is a moderate resolution spectrometer covering wavelengths from 290 nm to 1550 nm. Science data is collected in solar occultation mode, lunar occultation mode, and limb scatter measurement mode. A SpaceX Falcon 9 launch vehicle will provide access to space. Mounted in the unpressurized section of the Dragon trunk, SAGE III will be robotically removed from the Dragon and installed on the space station. SAGE III/ISS will be mounted to the ExPRESS Logistics Carrier 4 location on the starboard side of the station. To facilitate a nadir view from this location, a Nadir Viewing Platform payload was developed which mounts between the carrier and the SAGE III Instrument Payload.

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.

Astronauts routinely perform submaximal graded exercise testing using cycle ergometry before and during International Space Station (ISS) missions. Aerobic capacity has been estimated from linear extrapolation of heart rate (HR) response and submaximal oxygen consumption (VO2). The elevated HR response to standardized exercise work rates during ISS flight typically has been interpreted as aerobic deconditioning. However, until recently VO2 has not been measured during these tests. PURPOSE: To determine if submaximal VO2 and HR measured during exercise tests on the ISS differ from preflight values as a function of time on board and of exercise intensity. METHODS: Astronauts (n=7) performed exercise tests before flight on a standard cycle ergometer and during flight on the ISS cycle ergometer. In-flight exercise tests were conducted at intervals between days 21 and 149 of the missions. The protocol for submaximal exercise tests consisted of three 5-minute stages at work rates prescribed to elicit 25, 50, and 75% of preflight peak VO2. HR was obtained from ECG and VO2 from metabolic gas analysis. Mixed modeling was used to examine the mean differences between preflight and in-flight measurements of VO2 and of HR over time and at each work rate. RESULTS: During flight, VO2 was significantly lower during the 25% and higher during the 75% exercise stages but did not differ from preflight VO2 at the 50% stage. These differences were consistent across in-flight time points. HR was unchanged from preflight HR at the 25% stage of exercise, although the HR at this stage tended to lower as flight duration increased. At the 50% and 75% stages, HR was elevated early during the missions but did not differ from preflight values later during flight. CONCLUSIONS: The preflight relationship between VO2 and work rate is not maintained during flight, perhaps because of microgravity and/or differences between the ergometers. The changing HR responses across mission duration, some of which do not parallel the VO2 findings, may indicate an acute adaptation early during flight that normalizes later during the missions, and/or an exercise training effect during flight. Thus, estimating aerobic capacity during flight by using only HR responses to submaximal work rates may result in erroneous conclusions. Supported by NASA Contract NAS 9-02078

Introduction Caffeine is the most widely used performance-enhancing drug on Earth and astronaut crews have access to liquid coffee. While caffeine is a potent countermeasure to improve alertness and performance, it can also interfere with sleep. This can lead to performance deficits on the following day, driving a cycle of caffeine use to counter the effects of caffeine-induced sleep disruption. Caffeine availability may be limited during future Artemis and/or Mars missions. Therefore, we aimed to characterize how caffeine is used aboard the International Space Station (ISS) to better inform future spaceflight operations. Methods Daily caffeine consumption was determined from food and beverage intake tracking for 25 astronauts (11F) on 6-month International Space Station (ISS) missions. Data were recorded using the ISS Food Intake Tracker iPad App or other detailed recording technique. On average, crew recorded dietary intake on 179.7±68.6 (mean±SD) days inflight. Results Astronauts consumed 97±92 mg caffeine per day. All astronauts (25/25) in this study consumed caffeine at some point during flight, though the frequency, amounts, and regularity differed across crewmembers. Approximately a quarter of crewmembers were regular caffeine consumers (6/25), i.e., they ingested at least 90 mg caffeine (equivalent to one cup of coffee) on 90% of inflight days. Conclusion Our findings demonstrate that caffeine is regularly consumed by astronauts, though consumption patterns vary across individuals. Future analyses will involve evaluating these data in light of sleep and performance outcomes. This information will provide us with an understanding of how caffeine is being used inflight to help guide future countermeasure development. Support (if any)

Reports show that prolonged exposure to a spaceflight environment produces morphologic and functional ophthalmic changes in astronauts during and after an International Space Station (ISS) mission. However, the underlying mechanisms of these spaceflight-induced changes are currently unknown. The purpose of the present study was to determine the impact of the spaceflight environment on ocular structures by evaluating the thickness of the mouse retina, the retinal pigment epithelium (RPE), the choroid and the sclera layer using micro-CT imaging. Ten-week-old C57BL/6 male mice were housed aboard the ISS for a 35-day mission and then returned to Earth alive for tissue analysis. For comparison, ground control (GC) mice on Earth were maintained in identical environmental conditions and hardware. Ocular tissue samples were collected for micro-CT analysis within 38(±4) hours after splashdown. The images of the cross-section of the retina, the RPE, the choroid, and the sclera layer of the fixed eye was recorded in an axial and sagittal view using a micro-CT imaging acquisition method. The micro-CT analysis showed that the cross-section areas of the retina, RPE, and choroid layer thickness were changed in spaceflight samples compared to GC, with spaceflight samples showing significantly thinner cross-sections and layers compared to controls. The findings from this study indicate that micro-CT evaluation is a sensitive and reliable method to characterize ocular structure changes. These results are expected to improve the understanding of the impact of environmental stress on global ocular structures.

Astronauts often face orientation challenges while on orbit, which can lead to operator errors in demanding spatial tasks. In this study, we investigated the impact of long-duration spaceflight on the neural processes supporting astronauts' spatial orientation skills. Using functional magnetic resonance imaging (fMRI), we collected data from 16 astronauts six months before and two weeks after their International Space Station (ISS) missions while performing a spatial orientation task that requires generating a mental representation of one's surroundings. During this task, astronauts exhibited a general reduction in neural activity evoked from spatial-processing brain regions after spaceflight. The neural activity evoked in the precuneus was most saliently reduced following spaceflight, along with less powerful effects observed in the angular gyrus and retrosplenial regions of the brain. Importantly, the reduction in precuneus activity we identified was not accounted for by changes in behavioral performance or changes in grey matter concentration. These findings overall show less engagement of explicitly spatial neurological processes at postflight, suggesting astronauts make use of complementary strategies to perform some spatial tasks as an adaptation to spaceflight. These preliminary findings highlight the need for developing countermeasures or procedures that minimize the detrimental effects of spaceflight on spatial cognition, especially in light of planned long-distance future missions.

The photovoltaic radiator (PVR) is designed to reject the waste heat of the PV power generation and storage system. The requirement has been added to provide heat rejection for the Early External Active Thermal Control System to support the Assured Early Research phase of the International Space Station (ISS) Mission. The new requirement has resulted in the reanalysis and some redesign of the hardware. In addition, the new use of the PVR hardware has resulted in a significantly earlier launch date. This paper describes the PVR design with emphasis on the design changes made to incorporate the new mission requirements. The verification methods are discussed and the results of analysis and testing accomplished to date are summarized.

As the international space community plans for manned missions to Mars, spaceflight-associated immune dysregulation has been identified as a potential risk to the health and safety of the flight crew. There is a need to determine whether salivary antimicrobial proteins, which act as a first line of innate immune defense against multiple pathogens, are altered in response to long-duration (>6 mo) missions. We collected 7 consecutive days of whole and sublingual saliva samples from eight International Space Station (ISS) crewmembers and seven ground-based control subjects at nine mission time points, ~180 and ~60 days before launch (L-180/L-60), on orbit at flight days ~10 and ~90 (FD10/FD90) and ~1 day before return (R-1), and at R+0, R+18, R+33, and R+66 days after returning to Earth. We found that salivary secretory (s)IgA, lysozyme, LL-37, and the cortisol-to-dehydroepiandrosterone ratio were elevated in the ISS crew before (L-180) and during (FD10/FD90) the mission. "Rookie" crewmembers embarking on their first spaceflight mission had lower levels of salivary sIgA but increased levels of α-amylase, lysozyme, and LL-37 during and after the mission compared with the "veteran" crew who had previously flown. Latent herpesvirus reactivation was distinct to the ~6-mo mission crewmembers who performed extravehicular activity ("spacewalks"). Crewmembers who shed at least one latent virus had higher cortisol levels than those who did not shed. We conclude that long-duration spaceflight alters the concentration and/or secretion of several antimicrobial proteins in saliva, some of which are related to crewmember flight experience, biomarkers of stress, and latent viral reactivation.NEW & NOTEWORTHY Spaceflight-associated immune dysregulation may jeopardize future exploration-class missions. Salivary antimicrobial proteins act as a first line of innate immune defense. We report here that several of these proteins are elevated in astronauts during an International Space Station mission, particularly in those embarking on their first space voyage. Astronauts who shed a latent herpesvirus also had higher concentrations of salivary cortisol compared with those who did not shed. Stress-relieving countermeasures are needed to preserve immunity and prevent viral reactivation during prolonged voyages into deep space.

Space travel: medicine in extremes

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.

The International Space Station (ISS) is the product of the efforts of sixteen nations over the course of several decades. It is now complete, operational, and has been continuously occupied since November of 20001. Since then the ISS has been carrying out a wide variety of research and technology development experiments, and starting to produce some pleasantly startling results. The ISS has a mass of 420 metric tons, supports a crew of six with a yearly resupply requirement of around 30 metric tons, within a pressurized volume of 916 cubic meters, and a habitable volume of 388 cubic meters. Its solar arrays produce up to 84 kilowatts of power. In the course of developing the ISS, many lessons were learned and much valuable expertise was gained. Where do we go from here? The ISS offers an existence proof of the feasibility of sustained human occupation and operations in space over decades. It also demonstrates the ability of many countries to work collaboratively on a very complex and expensive project in space over an extended period of time to achieve a common goal. By harvesting best practices and lessons learned, the ISS can also serve as a useful model for exploring architectures for beyond low- earth-orbit (LEO) space development. This paper will explore the concept and feasibility for a Lunar Station. The Station concept can be implemented by either putting the equivalent capability of the ISS down on the surface of the Moon, or by developing the required capabilities through a combination of delivered materials and equipment and in situ resource utilization (ISRU). Scenarios that leverage existing technologies and capabilities as well as capabilities that are under development and are expected to be available within the next 3-5 years, will be examined. This paper will explore how best practices and expertise gained from developing and operating the ISS and other relevant programs can be applied to effectively developing Lunar Station.

Humoral and cellular immunity in cosmonauts after the ISS missions

The demand for highly flexible manipulation of plant growth generations and modification of specific plant processes in a controlled environment has led to the development of a Commercial Plant Biotechnology Facility (CPBF) for the International Space Station. The CPBF integrates proven ASTROCULTURE™ technologies, state-of-the-art control software, and fault tolerance and recovery technologies together to increase overall system efficiency, reliability, robustness, and flexibility. An open and modular design architecture minimizes the design effort of reconfiguration/reconstruction of the facility with different dimensions and capacities. An autonomous control system with fault tolerance and recovery capability minimizes the on-orbit crew intervention which is particularly valuable for Space Shuttle and International Space Station missions. A flexible user interface is provided for operators to select, define, and modify the tasks to be conducted. The CPBF consists of five major subsystems: the lighting c...

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.

During the summer of 2009, a flexible path scenario for human and robotic space exploration was developed that enables frequent, measured, and publicly notable human exploration of space beyond low-Earth orbit (LEO). The formulation of this scenario was in support of the Exploration Beyond LEO subcommittee of the Review of U.S. Human Space Flight Plans Committee that was commissioned by President Obama. Exploration mission sequences that allow humans to visit a wide number of inner solar system destinations were investigated. The scope of destinations included the Earth-Moon and Earth-Sun Lagrange points, near-Earth objects (NEOs), the Moon, and Mars and its moons. The missions examined assumed the use of Constellation Program elements along with existing launch vehicles and proposed augmentations. Additionally, robotic missions were envisioned as complements to human exploration through precursor missions, as crew emplaced scientific investigations, and as sample gathering assistants to the human crews. The focus of the flexible path approach was to gain ever-increasing operational experience through human exploration missions ranging from a few weeks to several years in duration, beginning in deep space beyond LEO and evolving to landings on the Moon and eventually Mars.