International Space Station Medical Monitoring (ISS Medical Monitoring) - 11.22.16

Overview | Description | Applications | Operations | Results | Publications | Imagery

ISS Science for Everyone

Science Objectives for Everyone
Medical Monitoring On Board the International Space Station (ISS) (Medical Monitoring) involves the collection of health data at regular intervals from long-duration International Space Station (ISS) crewmembers. Crew health before, during and following space flight is essential to overall ISS mission success. All of the partner agencies recognize the importance of crew health to mission success and are dedicated to maintaining the health of all crewmembers throughout all phases of ISS missions.
Science Results for Everyone
Talk about a wealth of data. Many studies have used health data collected from space station crewmembers. One of them found that long-duration space flight prolongs recovery of heart muscle, while others suggested that microgravity affects the body’s balancing mechanisms. Other researchers used the data to develop guidelines for using high-tech tools to diagnose coronary artery disease, which will improve crew selection standards and help prevent cardiovascular illness during flight. The data are also helping develop new tools for biological and immunological testing in space, which will support space-related immune deficiency research and advance health care and environmental monitoring in remote and resource-poor areas.

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Experiment Details


Principal Investigator(s)

Information Pending

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Sponsoring Space Agency
National Aeronautics and Space Administration (NASA)

Sponsoring Organization
Human Exploration and Operations Mission Directorate (HEOMD)

Research Benefits
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ISS Expedition Duration
September 2000 - December 2002; November 2002 - May 2003; April 2003 - March 2014

Expeditions Assigned

Previous Missions
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Experiment Description

Research Overview

  • Crewmember medical data are collected for preflight, inflight and postflight phases per requirements described in Volume B of the ISS 50667 Medical Evaluation Documents (MED Vol B).

  • These operational medical monitoring requirements are used to determine flight readiness, establish baselines, guide inflight countermeasures and assessments, and guide postflight rehabilitation to return crewmembers to their preflight health status.


Medical specialists from all the partner agencies developed a document called Volume B of the ISS 50667 Medical Evaluation Documents (MED Vol B) which defines crew health evaluation requirements. The medical evaluation requirements apply to all ISS crewmembers and were agreed to by all the International Partner Agencies. Each Partner Agency is free to perform additional medical evaluations on their crewmembers. Crewmember evaluations can be added or repeated at the discretion of the Crew Surgeon.

The crew medical evaluations and monitoring activities can be organized into several broad categories: 1) Medical or Clinical; 2) Occupational Monitoring; 3) Physical Fitness; 4) Nutritional; and 5) Psychological or Behavioral Health.

  • Medical/Clinical Evaluations - In general, these evaluations include a typical physical examination by the crew surgeon, neurological assessment, vision, hearing and dental assessments, 24-hour ambulatory electrocardiograms, bone densitometry, ultrasound imaging, clinical laboratory tests (blood and urine) and body mass measurement.

    Preflight medical evaluations may be performed in the U.S., Russia, Europe, Japan or Canada. Examinations performed 10 days or less prior to flight are conducted in the U.S. or Russia depending on the launch site. Preflight examinations are coordinated and performed by the Crew Surgeon and medical specialists designated by the Partners for their crewmembers. Periodic inflight medical evaluations include crew conferences with ground specialists, inflight examinations by the designated Crew Medical Officer (CMO), radiation monitoring, and physical fitness tests. Postflight medical evaluations are used to evaluate postflight crew health, monitor rehabilitation and to ensure crew return to preflight medical status. 

  • Occupational Monitoring - Biodosimetry data is collected before and after flight to determine whether or not aberrations in chromosomes occur following space flight. In addition to crew monitoring, occupational monitoring of the space flight environment is performed on a regular basis and includes monitoring of radiation, air and water quality. 

  • Physical Fitness Evaluations - A submaximal, incremental load test is performed using the cycle ergometer to assess aerobic capacity preflight, periodically inflight and postflight. Functional fitness is assessed using “gym” exercises to evaluate strength, endurance, flexibility, agility and balance before and after flight. Strength and conditioning of ISS crew is also monitored in association with inflight crew exercise protocols. 

  • Nutritional Assessment - Preflight and postflight nutritional assessment includes determination of typical dietary intake using a questionnaire, blood and urine chemistries, as well as body mass and composition measurements. Inflight, dietary intake is monitored, body mass measurements and blood chemistry data are obtained on a periodic basis. 

  • Psychological/Behavioral Health Status - Assessment of crewmembers behavioral health status is primarily done by interviews with a psychiatrist or psychologist. Preflight, there is a general review of any life events that may impact behavioral health, as well as a review of the crewmembers’ support system, and a general mood assessment. Inflight, there are regularly scheduled private psychological conferences, monitoring of mood and evaluation of work/rest schedules. Postflight, there are regularly scheduled interviews to assess the crewmembers’ psychological readaptation to life on Earth.

The Crew Health Care System (CHeCS)/Integrated Medical System is a suite of hardware on the ISS that provides the medical and environmental capabilities necessary to ensure the health and safety of crewmembers during long-duration missions. CHeCS is divided into the following three subsystems:

  • Countermeasures System (CMS) - The CMS provides the equipment and protocols for the performance of daily and alternative regimens (e.g., exercise) to mitigate the deconditioning effects of living in a microgravity environment. The CMS also monitors crew-members during exercise regimens, reduces vibrations during the performance of these regimens, and makes periodic fitness evaluations possible.  

  • Environmental Health System (EHS) - The EHS monitors the atmosphere for gaseous contaminants (i.e., from nonmetallic materials off-gassing, combustion products, and propellants), microbial contaminants (i.e., from crewmembers and Station activities), water quality, acoustics, and radiation levels.  

  • Health Maintenance System (HMS) - The HMS provides inflight life support and resuscitation, medical care, and health monitoring capabilities. The medical kit includes the Ambulatory Medical Pack (AMP), the Advanced Life Support Pack (ALSP), the Crew Contamination Protection Kit (CCPK), a defibrillator, the Respiratory Support Pack (RSP), the Crew Medical Restraint System (CMRS), and the Medical Checklist.  The Medical Equipment Computer (MEC) downlinks data from the medical equipment that is capable of doing so and contains physiological monitoring software, an electronic medical record, and medical reference software, and is the platform for the computer-based medical training.

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Space Applications
The optimization of crew health and safety increases the productivity of their performance while conducting on-orbit operations. With humans currently occupying the International Space Station (ISS) for six months and space exploration missions of one to three years on the horizon, preservation of crewmember health status and monitoring is a major objective of the international space community.

Earth Applications
Maintaining crewmember health and safety while on orbit better ensures that crewmember functionality is not jeopardized as a result of time spent on a mission; therefore, allowing them to resume life on Earth unaffected by space travel.

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Operational Requirements and Protocols

Due to the varying degree of the activities performed as part of Medical Monitoring, there are no specific operational requirements.

For ISS, the crews are subject to a comprehensive launch minus 45-day complete physical exam, audiogram, ophthalmological assessment, dental exam, neurocognitive assessment, psychological assessment, nutritional status assessment, clinical lab assessment, microbiological assessment, musculoskeletal assessment, cardiovascular assessment, cardiopulmonary assessment and pulmonary function tests. These are repeated I various stages postflight to study the physiological return to earth’s gravity and to ensure that the crew returns to its preflight status.

Inflight there are periodic health status evaluations performed by the CMOs every 30 days, with cardiopulmonary assessment, and urinalysis. There is also a 30-day fitness test scheduled every 30 days that occurs in between the periodic health evaluations. There are 1 ½ hours of exercise baseline daily for each crewmember. The postflight medical exams and postflight rehabilitation are used to measure and to restore physician health to the preflight baseline.

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Decadal Survey Recommendations

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Results/More Information

Medical Monitoring covers a wide array of distinct ISS investigational studies. Below are some of the results which encompass the Medical Monitoring on ISS.

The US-based health care system of the International Space Station (ISS) contains several subsystems, the Health Maintenance System, Environmental Health System and the Countermeasure System. This system is designed to stabilized and transport an ill or injured crewmember rapidly to a medical care facility on Earth rather than treating for an extended period on orbit. The medical requirements of the short- (7 day) and long-duration (up to 6 months) exploration class missions are similar to low Earth orbit (LEO) class missions but also include an additional 4 to 5 days needed for medical transportation back to Earth.

Since return to Earth and a complete compliment of medical care is improbable for exploration class missions beyond LEO and the moon, NASA has identified five levels of care as part of its approach to medical support of future missions: implement an effective medical risk mitigation strategy for exploration class missions, modifications to the current suite of space medical systems may be needed, including new crew medical officer training methods, treatment guidelines, diagnostic and therapeutic resources, and improved medical informatics (Hamilton et al 2008).

A study has found that long-duration, but not short-, space flight prolongs cardiac electrical conduction and heart muscle recovery. Shifts in systemic cardiac regulation and primary cardiac changes may be responsible. Long-duration flight is associated with slower heart rate and may increase arrhythmia susceptibility. It is recommended that medication which decrease the heart rate should be administered with caution during and after long-duration space flight (D’Aunno et al. 2003).

The screening tests for coronary artery disease (CAD) for active and potential astronauts are similar to those performed in the 1960s. Due to the limited treatment and return capabilities of most space vehicles, an in-flight cardiac event could result in mission failure. The current standards used for astronaut selection have been successful in creating a group that has less risk than the general population. However, the existing astronaut cardiovascular screening and selection tests do not adequately rule out CAD for long-duration mission, and therefore, a “significant” risk of cardiac event remains, especially as we look toward Exploration Class missions. Future research should be directed toward increasing the primary and secondary prevention of CAD in astronauts. Meanwhile, cardiovascular diagnostic advancements should be fully utilized to improve screening. As the international space programs move into a new era of exploring interplanetary travel, diagnostic and treatment capabilities in space will be essential to mitigate the risks to cardiovascular health (Hamilton et al 2008).

Highly sensitive and selective cardiovascular screening before flight is the most effective method of reducing the risk of a cardiac event in space. Current studies support adding electron-beam computed tomography (EBCT) and highly selective C-(capsular) reactive protein (hsCRP) for diagnosis of coronary artery disease (CAD) in current and future candidates for space missions. The recommended initial astronaut selection and long-duration mission assignment screening algorithms use EBCT-derived calcium scores and serum hsCRP levels to screen for CAD and predict individual cardiac risk. The proposed screening methods with the latest diagnostic capabilities attempt to improve on the current selection and retention standards, and also fulfill the operational space medicine goal of preventing the occurrence of cardiovascular illness or impaired performance during space flight (Hamilton et al 2006).

The likelihood of cardiopulmonary resuscitation (CPR) being performed in space exploration is very low but not non-existent. CPR in microgravity via closed chest compression is thought to be possible by several techniques. This study examined the handstand, side, and waist straddle maneuvers, and a bear hug technique in performing CPR and meeting American Heart Association (AHA) recommendations in microgravity. We also hypothesized that one rescuer using a CPR bellows adjunct device is equivalent to two rescuers. CPR in microgravity is most reliably performed in the handstand position and meets AHA guidelines for closed chest compression depth. One-rescuer CPR incorporating the Kendall CardioVent device (a cylindrical, compressible plastic human-powered mechanical device with a soft, rigid attachment, that fits on the sternum, for delivery of closed chest compressions) appears promising in microgravity, and CPR aiding devices would positively impact resuscitative procedures limited in manpower. Two-rescuer CPR in microgravity is most reliably performed in the handstand position (Jay et al. 2006).

In order to serve as Crew Medical Officers (CMO), astronauts receive 40-70 hours of medical training within 18 months before missions, including cardiopulmonary resuscitation (CPR) per the Guidelines of the AHA. It is found that CPR timing devices, that coordinated the delivery of both breaths and compressions to a simulated heart arrest patient, improve performance of CPR by ISS astronaut CMO analogues. Implementation of timing devices into CPR training and CPR medical kits can therefore assure better compliance with the standard of care for treating cardiac arrest by individuals of nonmedical professions in terrestrial settings as well as extreme environments such as space flight aboard the ISS (Hurst et al. 2006).

Historically, studies of physiological responses to microgravity have not been aimed at examining gender-specific differences in astronauts. One of the reasons for this is that the relatively small number of the female astronauts compared with the males generally precludes having sufficient statistical power to draw valid conclusions about gender differences. In addition, individual differences in physiological responses within genders are usually as large as, or larger than, differences between genders, so individual characteristics usually outweigh gender differences. The only astronaut health issue for which a large enough data set exists to allow valid conclusions to be drawn about gender differences is post-flight orthostatic intolerance (inability to maintain normal blood pressure in the standing position) following shuttle missions, in which women have a significantly higher incidence of presyncope (experiencing the symptoms without actually fainting) during stand tests than do men. However, the first American astronauts who flew aboard Mir (almost all of whom were men) had an 85% failure rate during the postflight tilt test. Thus it is expected that gender-related differences will not be apparent on long-duration missions. Other gender-specific issues that are likely to have functional or operational impacts for astronauts on long-duration missions include ventricular dysrhythmias (irregular heartbeat), bone and calcium changes associated with osteoporosis, menstrual function, and radiation effects on gametes. Although gender differences in aerobic capacity and muscle strength are not considered health issues per se, ground-based data suggest that women may be more susceptible to fatigue and injury, particularly during more strenuous tasks. Finally, an emerging body of evidence suggests that there are gender-specific differences in effectiveness and adverse effects of pharmacological (drug) treatment. Insufficient data exist in most of the discipline areas at the present time to draw valid conclusions about gender-specific differences in astronauts or to determine their impact on the health of male and female astronauts. Understanding these differences is likely to become more important for long-duration International Space Station and exploration missions.

Research has shown that the immune system is less efficient during space flight. Miniature and semi-automated diagnostic systems to perform a set of biological and immunological tests on board spacecrafts will allow the study of the causes of space-related immune deficiency and the development of countermeasures to maintain an optimal immune function and prevent infectious diseases during space missions. By monitoring the astronaut’s immune responses on one side, and their environment on the other side, new set of diagnostic tools will fill our knowledge gap and decrease one of the risks of space missions. In addition, the development of a micro-flow cytometer (cell counter) with the characteristics needed for space flight (low power consumption, small footprint) will have great impact on point-of-care diagnostics and medical facilities in remote areas and resource-poor countries and in situ environmental monitoring and control. Similarly, the automation and miniaturization of DNA-based analytical tests will be greatly beneficial to medical care on Earth.

NASA’s ISS astronauts undergo an extremely challenging training flow lasting 3 to 4 years before launch. Then the mission itself, lasting up to 6 months, presents the challenges of isolation, confinement, demanding workload, and family disconnection. The post-landing period of extended physical rehabilitation and reintegration presents yet another hurdle. ISS families, in turn, face the challenge of life at home without their astronaut spouse or parent. To state that all of this is psychologically demanding, is certainly an understatement. Fortunately, NASA has a dedicated team of professionals whose primary goal is to provide psychological support to ISS astronauts and their families. The Johnson Space Center (JSC) Behavioral Health & Performance (BHP) group is a multidisciplinary team of mental health professionals. ISS astronauts are assigned their BHP team 2 years before their actual launch, prior to assignment as back-up ISS crewmember. Inflight services consist of: psychological support hardware, crew care packages (CCP), recreational materials, personal videos/photo uplinks, news and information uplinks, and private family conferences (PFC). Psychological support hardware is individualized, although some hardware, like a guitar and keyboard, remain on the ISS. Items in the 4-kg CCP are provided by family, friends, the BHP team, and co-workers. Favorite foods, surprise gifts from the family, and holiday decorations are a few of the items that have been sent to the ISS in CCP’s. The most valued of these is the Private Family Conference (PFC). This deeply appreciated communication service occurs each weekend with videoconference equipment placed in the astronaut’s home that allows private two-way video and audio between the astronaut and their family. Another very popular means of communication is the internet protocol (IP) telephone. This enables the astronaut to have communication with anyone on the ground via private phone call. ISS astronauts also have email capabilities. Crew Discretionary Events (CDE) are also very popular among ISS crewmember. These are special requests from the astronaut to make contact (audio or video) from the ISS with extended family members, celebrities, military academies, and others that help boost the morale of the ISS crew. JSC Public Affairs Office and Education Office events also occur during a mission that help lift the morale of the astronauts, and BHP works in collaboration with these offices (Beven et al. 2008).

To date, a total of 219 in-flight musculoskeletal injuries have been identified, 198 occurring in men and 21 in women. Though no inflight musculoskeletal injury to date has caused a failure of mission objectives, preflight musculoskeletal injuries have resulted in some impacts to planned mission activities. Crew activity in the spacecraft cabin such as floating between modules, aerobic and resistive exercise, and injuries caused by the extravehicular activity (EVA) suit components were the leading causes of musculoskeletal injuries. Hand injuries represented the most common location of injuries, with abrasions and small lacerations representing common manifestations of these injuries. Exercise-related injuries is the most frequent source of injuries in astronauts living aboard the ISS. Interaction with EVA suit components has also accounted for injuries as well. Indeed, body measurement data obtained from in-suit analysis has shed light on injury patterns related to the EVA suit. Inflight problems such as back pain related to off-loading of the axial skeleton in microgravity or fingertip injuries due to stiff gloves or suit compliance could be mitigated or prevented with proper adjustments or countermeasures. Identifying the incidence and mechanism of inflight injuries will allow flight surgeons to quantify the amount of medical supplies needed in the design of next-generation spacecraft. Engineers can use inflight injury data to further refine the EVA suit and vehicle components. As NASA looks toward exploration missions beyond low- earth orbit, evidence-based data on in-flight musculoskeletal injuries will be critical in helping astronauts achieve their mission safely and effectively.

Back pain is frequently reported by astronauts during the early phase of space flight as they adapt to microgravity. The incidence of space adaptation back pain among astronauts was determined to be 52%. Most (86%) of the affected astronauts reported mild pain. Moderate pain was reported by 11% of the affected astronauts and severe pain was reported by 3% of the affected astronauts. The incidence of Space Adaptation Back Pain (SABP) among male astronauts was slightly lower (6%) than among female astronauts. In terms of the location of pain, of those astronauts who reported location, 86% reported lumbar pain for the majority of cases. SABP was present in the early phase of space flight, with peak prevalence on flight day 2. None of the astronauts reported SABP after flight day 12 and only two astronauts reported SABP after flight day 10. Most astronauts with SABP reported symptoms during the sleep period. There were 10% who reported symptoms only during the day and 15% reported symptoms during both the day and night. In terms of the treatment of SABP, the most effective treatments were bending the knees to the chest (91% effective) or stretching the lumbar spine (90% effective). It should be noted that crewmembers who reported that stretching of the spine was an effective treatment described the stretching as bringing their knees to their chest (fetal positioning). The next most effective treatments, not exclusive of each other, were the use of analgesic medication (ibuprofen or acetaminophen) and exercise (primarily treadmill and cycle ergometer) which were 85% effective. The results of this study confirmed many of the findings of previous studies of SABP, and further supports the hypothesis that SABP is related to spinal lengthening during exposure to microgravity. However, the specific mechanism and spinal structures responsible for SABP require further investigation. Although SABP is common among astronauts, most cases are mild, self-limited, or responsive to available treatments. To date, there has been no documented evidence of direct operational mission impact related to SABP. However, there is the potential for mission impact due to impaired crew performance related to uncontrolled pain, sleep disturbance, or the adverse side effects of medications. A better understanding and management of SABP may result in improved crew health and performance on future space missions.

A survey was distributed to 77 Space Shuttle flight crewmembers to capture historical information before Shuttle retirement and to better understand subjective experiences of illusory sensations due to the transition from Earth’s gravity to microgravity and back. Analysis of the response data (52% response rate) gave answered to 4 basic questions:

  • 1) Do older astronauts suffer more from illusory sensations than younger astronauts? No, since younger flight crew had about twice the rate of illusory sensations as older flight crew.
    2) Do trial head motions during re-entry in an effort to hasten re-adaptation to 1-G really help? Apparently not because those who made trial head motions had a 38% rate of illusory sensations whereas those who did not make trial head motions had a 15% rate of illusory sensations.
    3) Do symptoms decrease as flight experience increases? Yes, as reported in other publications, although there are individual exceptions.
    4) Do longer duration missions lead to more illusory sensations and re-adaptation difficulties than shorter duration missions? Yes, the rate of illusory sensations for longer missions was 38%, whereas it was 24% for shorter missions.

Based upon the results, long-duration missions may induce longer lasting orientation problems and more illusory sensations which could impact a mission. It is this conclusion that is of most concern for space explorers who will go to destinations where mission durations can last months, if not years. Mission planners should account for these physiological effects that may last for days or even weeks.

Considerable mission data has been accumulated, including data from female astronauts on the many Shuttle and International Space Station (ISS) missions, and confirmed that space flight is associated with weight loss. More than 80% of astronauts lost bodyweight during space flight. The decrease in bodyweight from preflight to return [R0 and R+1] days was statistically significant (- 2.1 ± 0.1%, N = 514) in both men (N=434) and women (N=80), and did not differ in magnitude between men and women. During this first post-mission interval, bodyweight increased in men while it continued to decrease in women. However, female astronauts subsequently regained weight so that overall postflight recovery of bodyweight between R [0-1] days and R [91-396] days did not differ significantly between genders. No association between age and changes of bodyweight during space flight was found. Overall, mission duration has the strongest association with loss of bodyweight during space flight. First-time astronauts are more susceptible to bodyweight loss in space than space flight veterans. A likely underlying factor in the greater weight loss on first-time missions is that first-time astronauts are more likely to experience space motion sickness. The lower average weight loss measured in experienced astronauts might be explained by a “training effect” on physical energy expenditure, analogous to the training effect seen in athletes, or to better space adaptation. Evidently, astronauts who performed more EVAs lost less bodyweight. This previously unreported observation may result from consumption of extra calories in excess of energy expended during EVA. The principal finding is that mission duration is the strongest predictor of weight loss. Analysis of data suggests that space missions of greater than 1-yr duration are likely to be associated with physiologically significant weight loss for some astronauts. This analysis is the first report of biological predictors of weight loss during space flight, including baseline serum cholesterol, potassium, and chloride levels (Matsumoto 2011).

Iodine is often used for water purification and has been used throughout the U.S. space program as a bactericidal agent in the water system. Because of concern about potential effects on crewmembers ’ thyroid function from excessive iodine intake, a system was installed on board the Space Shuttles in 1997 to remove iodine from water before it was consumed. Research data provide evidence that crewmembers ’ increase in serum thyroid stimulating hormone (TSH) on landing day after early Shuttle flights resulted from their consumption of iodinated water during space flight, since the same increase was not observed after implementation of the iodine removal system. Although this had been shown with a much smaller number of subjects a decade ago when the ion-exchange resin filter had been installed and most of the iodine was removed from the potable water system, the new data provide added confidence in these findings. The thyroid responses to iodine and space flight were generally similar in men and women. That is, after flights with iodinated water, both men and women tended to have higher circulating TSH concentrations, whereas after implementation of the iodine removal system, neither men nor women had a change in circulating TSH levels. Iodine is also used as the disinfectant in the U.S. potable water system on the ISS, and is removed by an iodinated resin filter similar to that used on the Space Shuttle. Pre- and post flight urinary iodine of ISS crewmembers are typically similar, and recent in-flight measurements on ISS crews showed no change from preflight values in urinary iodine excretion (Smith et al. 2011).

Currently, medical professionals have minimal experience and guidance when evaluating and certifying commercial space flight participants who may be older than the typical astronaut and more likely to have medical problems that place them at risk during flight. The new era in commercial and tourism space flights will provide important data for evaluating medical conditions, creating appropriate medical standards, and optimizing treatments. Non-career astronauts applying for commercial suborbital and orbital space flight will, at least in the near future, challenge aerospace physicians with unknowns regarding safety during training and flight, and highlight important ethical and risk-assessment problems. The information obtained from this new group of space travelers will provide important data for the evaluation and in-flight treatment of medical problems that space programs have not yet addressed systematically, and may improve the medical preparedness of exploration-class missions. As personal health data for non-professional space travelers become available and accessible, space medicine practitioners can use the data from subsequent space flight participants to expand their ability to care for humans in space far beyond that learned from healthy career astronauts (Jennings et al. 2006, 2010).

The medical community of the International Space Station (ISS) has developed joint medical standards and evaluation requirements which are used by the ISS medical certification board to determine medical eligibility for Space Flight Participants (SFPs or “space tourists”) for short-duration space flight to the ISS. It is emphasized that the criteria applied to the ISS space flight participant candidates are substantially less stringent than those for professional astronauts and/or crewmembers to the ISS. These medical standards are released by the government space agencies to facilitate the development of robust medical screening and medical risk assessment approaches in the context of the evolving commercial human space flight industry. SFPs initially undergo medical scrutiny by the certification board of the sponsoring agency, and only then by the ISS Multilateral Space Medicine Board (MSMB). The MSMB typically hears medical risk analysis presentations to consider the probability of disease manifestations against the magnitude of medical consequences and impact on the mission. Available risk mitigation measures in all mission phases are also taken into account in the final certification decisions. By May of 2007, the MSMB had considered eight SFP candidates. It is emphasized that SFPs carry no operational responsibilities and have full access to the ISS medical support system. All concerns were resolved within the MSMB through additional medical examinations and clinical deliberations with risk analysis. Five SFPs completed their training and were flown to the ISS for missions that lasted from 10 to 13 days. The established medical standards and evaluation requirements for SFPs are offered to the aerospace medicine and commercial space flight communities for reference purposes, to facilitate the development of medical screening approaches and risk assessment methodology in the context of the rapidly developing commercial human space flight industry.

In accordance with the Memorandum of Understanding on the ISS between the Russian Space Agency (RSA), NASA and the other international partners, multilateral medical working bodies have been created to coordinate and to carry out the practical work of standardizing requirements for the medical care of crewmembers at all stages of preparation and implementation of the ISS space program, as well as integrated bodies of operational medical mission control. The medical operations control structure that has been created makes it possible to adequately react to emerging problems, ensuring the maintenance of health and performance levels that are required from the crew in order to carry out flight objectives. So far, no serious clinical problems in crewmembers have been observed, even though there have been some personal differences in the adaptive reactions of the crewmembers’ functional systems to space flight conditions. Onboard life support systems and means on ISS have been basically sufficient and adequate, and periodically occurring temporary failures of certain life support systems have had no impact on the state of health of the crewmembers. The sanitary and hygienic conditions on ISS have been generally satisfactory and have corresponded to ISS Medical Operations Requirements Document (MORD) rules throughout the flights. Noise levels that are 4–24 dB higher than normal limits have been register on ISS, which sometimes calls for extra measures in the form of antinoise earplugs and hearing protection devices. According to medical control data, there have been periodic occurrences of germ or fungus levels on certain surfaces of the station’s interior in excess of normal limits, which can be promptly neutralized by onboard means (treating these surfaces with antiseptics and fungicide). Air quality throughout the ISS operation has been in line with the requirements of standards. There have been no serious problems with respect to water supply and nutrition systems, except for the late 2004, when a temporary food crunch occurred because of the Progress transport ship’s one-month delay. Nevertheless the attachment of modules, cargo and transport ships saturated with non-metal materials, and gas releases from cargo delivered to ISS were the main sources of extra chemical contamination of the ISS’ air environment. Data collected show the need for an improvement in the toxicological and hygienic measures taken in the process of preparations for the flight on the ground. Increase in the content of harmful trace contaminants is more often than not related to the arrival of visiting expeditions, new objects and hardware to ISS or to temporary failures in different life support systems. Radiation impacts have not been outside of the expected range. In periods of solar activity and an increasing threat of proton events the Alert regime is called, which provides for strengthened (uninterrupted) radiation control, using radiation sensors, which were placed in cosmonauts’ suits, and the cosmonauts’ withdrawal to the best protected areas of the stations in the periods of the greatest radiation danger (large diameter of the service module next to onboard training simulators). The mental ability and performance of the crews have been in line with the flight conditions. The work and rest schedule was tense during joint activities performed together with visiting crews, during the change of the main crews, and also during the preparations for and implementation of EVA, during repair and maintenance works, which was accompanied by sleep shifts, periodic occurrences of disruption of circadian rhythm excessive workloads and work on holidays.

Since the start of the Russian and American manned space programs, cosmonauts and astronauts have used glasses and contact lenses for visual correction during space operations.  Since these traditional vision correction devices have proven less than ideal for use in space, refractive surgery would appear to be a logical alternative.   This study followed an astronaut who had photorefractive keratectomy (PRK) surgery done many years prior to flight on a 12-day mission to the ISS to record any visual responses corneal surgery may have in microgravity.  The subject reported no change in visual ability over the course of the mission from what he observed on Earth.  Even though the astronaut’s eyes were subjected to a wide spectrum of physiologic changes while in space, no measurable changes in distance or near visual acuity, no hyperopic shift in refraction, or change in the amplitude of accommodation were documented during launch, 12 days on ISS, and reentry. This finding shows, in this case, that post-PRK cornea was not significantly affected by microgravity conditions and suggests that PRK is a safe, effective, and well-tolerated procedure for use by astronauts during spaceflight (Gibson et al. 2012).

Four astronaut subjects were studied before and during a 16-day space flight to determine heart rate (HR) and vascular responses to forearm exercise and blood flow reduction (oxygen starvation).  The test included 2 minutes of rest, 2 minutes of sustained handgrip (SHG), and 2 minutes of post-exercise circulatory occlusion (PECO), or constriction of blood flow.  The study found HR response to brain control during SHG was significantly reduced in-flight.  At the same time, heart rate and mean arterial blood pressure responses to localized muscle oxygen starvation did not differ between pre-flight control and in-flight measurements. Together with a parallel study of PECO after dynamic leg exercise, data demonstrate that the cardiovascular responses to muscle ischemia (blood flow restriction) are better maintained in microgravity than during ground head-down tilt (HDT) test. These findings confirm and extend observations of enhanced cardiovascular responses to post-exercise leg muscle ischemia during spaceflight.  Thus, the central processing of metaboreflex (the reaction of local nerves to anaerobic stress in muscles)  stimuli is likely unchanged and local sensitivity to such stimuli is enhanced in antigravity muscles (legs), but not in arm muscles, during sustained microgravity.  In contrast, the central nervous (brain)/mechanoreflex (pressure or distortion) component of the HR response to arm PECO was reduced in microgravity (Karlsson et al. 2009).


Three independent subject groups that included balance impaired patients, normal subjects before and after 30 minutes of 40% bodyweight unloaded treadmill walking, and astronauts before and after long-duration space flight were tested to determine body load-sensing and vestibular(inner ear canals) sensing influences on head movement control during treadmill walking after long-duration space flight.  Data collected show that exposure to unloaded walking caused a significant increase in head pitch movements in normal subjects, whereas the head pitch movements of impaired patients were significantly decreased. This is the first evidence of adaptation of vestibular mediated head movement responses to unloaded treadmill walking.  Astronaut subjects showed mixed response of both increases and decreases in the amplitude of head pitch movement.  These results indicate that body load-sensing input centrally influences vestibular input and can adaptively modify vestibular control of head-movement during locomotion. Thus, space flight may cause central adaptation of the converging vestibular and body load-sensing systems leading to alterations in head movement control (Mulavara et al. 2012).



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Results Publications

    Orwoll ES, Adler RA, Amin S, Binkley N, Lewiecki EM, Petak SM, Shapses SA, Sinaki M, Watts NB, Sibonga JD.  Skeletal Health in Long-Duration Astronauts: Nature, Assessment, and Management Recommendations from the NASA Bone Summit. Journal of Bone and Mineral Research. 2013 Jun; 28(6): 1243-1255. DOI: 10.1002/jbmr.1948.

    Mulavara AP, Ruttley TM, Cohen HS, Peters BT, Miller CA, Brady R, Merkle LA, Bloomberg JJ.  Vestibular-somatosensory convergence in head movement control during locomotion after long-duration space flight. Journal of Vestibular Research - Equilibrium & Orientation. 2012; 22(2-3): 153-166. DOI: 10.3233/VES-2011-0435. PMID: 23000615.

    Pastushkova LK, Valeeva OA, Kononikhin AS, Nikolaev EN, Larina IM, Dobrokhotov IV, Popov IA, Pochuev , Kireev KS, Grigoriev AI.  Changes in urine protein composition in human organism during long term space flights. Acta Astronautica. 2012 December; 81(2): 430-434. DOI: 10.1016/j.actaastro.2012.08.029.

    Smith SM, Zwart SR, McMonigal KA, Huntoon .  Thyroid Status of Space Shuttle Crewmembers: Effects of Iodine Removal. Aviation, Space, and Environmental Medicine. 2011 January 1; 82(1): 49-51. DOI: 10.3357/ASEM.2926.2011. PMID: 21235106.

    Pastushkova LK, Kireev KS, Kononikhin AS, Tiys ES, Popov IA, Starodubtseva NL, Dobrokhotov IV, Ivanisenko VA, Larina IM, Kolchanov NA, Nikolaev EN.  Detection of renal tissue and urinary tract proteins in the human urine after space flight. PLOS ONE. 2013 August 13; 8(8): e71652. DOI: 10.1371/journal.pone.0071652. PMID: 23967230.

    Hurst, IV VW, Whittam , Austin , Branson , Beck .  Cardiopulmonary Resusicitation During Spaceflight: Examining the Role of Timing Devices. Aviation, Space, and Environmental Medicine. 2011 August; 82(8): 810-813. DOI: 10.3357/ASEM.2284.2011. PMID: 21853860.

    Clement G, Ngo-Anh JT.  Space Physiology II: Adaptation of the Central Nervous System to Space Flight - Past, Current and Future Studies. European Journal of Applied Physiology. 2013 Jul; 113(7): 1655-1672. DOI: 1007/s00421-012-2509-3.

    Motkoski JW, Yang FW, Lwu SH, Sutherland GR.  Toward robot-assisted neurosurgical lasers. IEEE Transactions on Biomedical Engineering. 2013 April; 60(4): 892-898. DOI: 10.1109/TBME.2012.2218655.

    Wood SJ, Paloski WH, Clark JB.  Assessing sensorimotor function following ISS with computerized dynamic posturography. Aerospace Medicine and Human Performance. 2015 December 1; 86(12): 45-53. DOI: 10.3357/AMHP.EC07.2015. PMID: 26630195.

    Kotovskaya AR, Fomina GA.  Prediction of human orthostatic tolerance by changes in arterial and venous hemodynamics in the microgravity environment. Human Physiology. 2013 October 11; 39(5): 472-479. DOI: 10.1134/S0362119713050083.

    Prostyakov IV, Morukov BV, Morukov IB.  Changes in bone mineral density and microarchitecture in cosmonauts after a six-month space flight. Human Physiology. 2012 December 15; 38(7): 727-731. DOI: 10.1134/S0362119712070201. [Original Russian Text © I.V. Prostyakov, B.V. Morukov, I.B. Morukov, 2010, published in Aviakosmicheskaya i Ekologicheskaya Meditsina, 2010, Vol. 44, No. 3, pp. 24–28.]

    Pakharukova NA, Pastushkova LK, Samarin GI, Pochuev , Morukov BV, Larina IM.  Direct proteome profiling of the blood serum in cosmonauts after long-term space missions. Human Physiology. 2014 December; 40(7): 713-717. DOI: 10.1134/S0362119714070196.

    Oganov VS, Skripnikova IA, Novikov V, Bakulin AV, Kabitskaya OE, Murashko LM.  Characteristics of local human skeleton responses to microgravity and drug treatment for osteoporosis in clinic. Human Physiology. 2014 December; 40(7): 762-766. DOI: 10.1134/S0362119714070184. [Also: Original Russian Text © V.S. Oganov, I.A. Skripnikova, V.E. Novikov, A.V. Bakulin, O.E. Kabitskaya, L.M. Murashko, 2011, published in Aviakosmicheskaya i Ekologicheskaya Meditsina, 2011, Vol. 45, No. 4, pp. 16–21.]

    D'Aunno DS, Dougherty AH, DeBlock HF, Meck JV.  Effect of Short- and Long-Duration Spaceflight on QTc Intervals in Healthy Astronauts. American Journal of Cardiology. 2003 February 15; 91(4): 494-497. DOI: 10.1016/S0002-9149(02)03259-9.

    Jay , Lee PH, Goldsmith , Battat , Maurer , Suner .  CPR Effectiveness in Microgravity: Comparison of Three Positions and a Mechanical Device. Aviation, Space, and Environmental Medicine. 2003; 74(11): 1183 -1189. PMID: 14620476.

    Hamilton DR, Murray JD, Kapoor D, Kirkpatrick AW.  Cardiac health for astronauts: current selection standards and their limitations. Aviation, Space, and Environmental Medicine. 2005 Jul; 76(7): 615-626. PMID: 16018343.

    Law J, Van Baalen M, Foy M, Mason SS, Mendez C, Wear , Meyers VE, Alexander D.  Relationship between carbon dioxide levels and reported headaches on the international space station. Journal of Occupational and Environmental Medicine. 2014 May; 56(5): 477-483. DOI: 10.1097/JOM.0000000000000158. PMID: 24806559.

    Bacal K, Frey BM.  Selection of Medications for the International Space Station: The Space Medicine Patient Condition Database. Journal of Pharmacy Practice. 2003 Apr; 16(2): 91-95. DOI: 10.1177/0897190003016002003.

    Putro WS, Lestari RE.  The scoring quality of astronauts' sleeps using Fuzzy C-Means (FCM) during microgravity effect in the International Space Station (ISS). Scientific Journal of PPI - UKM. 2015; 2(1): 3 pp.

    Karlsson LL, Montmerle , Rohdin , Linnarsson D.  Central command and metaboreflex cardiovascular responses to sustained handgrip during microgravity. Respiratory Physiology and Neurobiology. 2009 October; 169: S46-S49. DOI: 10.1016/j.resp.2009.04.011.

    Bogomolov VV, Grigoriev AI, Kozlovskaya IB.  The Russian experience in medical care and health maintenance of the International Space Station crews. Acta Astronautica. 2007 February; 60(4-7): 237-246. DOI: 10.1016/j.actaastro.2006.08.014.

    Snigiryova GP, Novitskaya NN, Fedorenko BS.  Cytogenetic examination of cosmonauts for space radiation exposure estimation. Advances in Space Research. 2012 Aug 15; 50(4): 502-507. DOI: 10.1016/j.asr.2012.05.010.

    Afonin BV.  Analysis of possible causes of activation of gastric and the pancreatic excretory and incretory function after completion of space flight at the international space station. Human Physiology. 2013 October 11; 39(5): 504-510. DOI: 10.1134/S0362119713050022.

    Pastushkova LK, Kireev KS, Kononikhin AS, Tiys ES, Popov IA, Dobrokhotov IV, Ivanisenko VA, Noskov VB, Larina IM, Nikolaev EN.  Detection of renal and urinary tract proteins in urine before and after space flight. Human Physiology. 2013 October 11; 39(5): 535-539. DOI: 10.1134/S0362119713050125.

    Gibson CR, Mader TH, Schallhorn , Pesudovs K, Lipsky W, Raid , Jennings R, Fogarty J, Garriott , Garriott , Johnston SL.  Visual Stability of laser Vision Correction in an Adtronaut on a Soyuz Mission to the International Space Station. Journal of Cataract and Refractive Surgery. 2012; 38(3): 1486-1491. DOI: 10.1016/j.jcrs.2012.06.012.

    Small , Oman CM, Jones .  Space Shuttle Flight Crew Spatial Orientation Survey Results. Aviation, Space, and Environmental Medicine. 2012 April 1; 83(4): 383-387. DOI: 10.3357/ASEM.3180.2012.

    Bogomolov VV, Castrucci F, Comtois , Damann , Davis JR, Duncan JM, Johnston SL, Gray GW, Grigoriev AI, Koike , Kuklinski , Matveyev , Morgun VV, Pochuev , Sargsyan AE, Shimada , Straube , Tachibana S, Voronkov YI, Williams RS.  International Space Station Medical Standards and Certification for Space Flight Participants. Aviation, Space, and Environmental Medicine. 2007 December 1; 78(12): 1162-1169. DOI: 10.3357/ASEM.2175.2007.

    Hamilton DR, Murray JD, Ball .  Cardiac Health for Astronauts: Coronary Calcification Scores and CRP as Criteria for Selection and Retention. Aviation, Space, and Environmental Medicine. 2006; 77(4): 377-387. PMID: 16676648.

    Pastushkova LK, Valeeva OA, Kononikhin AS, Nikolaev EN, Larina IM, Dobrokhotov IV, Popov IA, Pochuev , Kireev KS.  Changes of protein profile of human urine after long-term orbital flights. Bulletin of Experimental Biology and Medicine. 2013 November; 156(2): 201-204. PMID: 24319748.

    Hayes J.  The first decade of ISS exercise: Lessons learned on expeditions 1–25. Aerospace Medicine and Human Performance. 2015 December 1; 86(12): 1-6. DOI: 10.3357/AMHP.EC01.2015. PMID: 26630187.

    English KL, Lee SM, Loehr JA, Ploutz-Snyder RJ, Ploutz-Snyder LL.  Isokinetic strength changes following long-duration spaceflight on the ISS. Aerospace Medicine and Human Performance. 2015 December 1; 86(12): 68-77. DOI: 10.3357/AMHP.EC09.2015.

    Nagaraja MP, Risin D.  The current state of bone loss research: data from spaceflight and microgravity simulators. Journal of Cellular Biochemistry. 2013 May; 114(5): 1001-1008. DOI: 10.1002/jcb.24454.

    Sutherland GR, Lama S, Gan LS, Wolfsberger S, Zareinia K.  Merging machines with microsurgery: Clinical experience with neuroArm. Journal of Neurosurgery. 2013 March; 118(3): 521-529. DOI: 10.3171/2012.11.JNS12877.

    Hamilton DR, Smart , Melton SL, Polk JD, Johnson-Throop .  Autonomous Medical Care for Exploration Class Space Missions. Journal of Trauma: Injury Infection and Critical Care. 2008 Apr; 64(4): S354-S363. DOI: 10.1097/TA.0b013e31816c005d.

    Jennings R, Garriott , Bogomolov VV, Pochuev , Morgun VV, Garriott .  Giant Hepatic Hemangioma and Cross-Fused Ectopic Kidney in a Spaceflight Participant. Aviation, Space, and Environmental Medicine. 2010 February 1; 81(2): 136-140. DOI: 10.3357/ASEM.2706.2010.

    Beven , Holland , Sipes .  Psychological Support for U.S. Astronauts on the International Space Station. Aviation, Space, and Environmental Medicine. 2008; 79(12): 1124. PMID: 19070310.

    Beaton-Green L, Lachapelle S, Straube , Wilkins RC.  Evolution of the Health Canada astronaut biodosimetry program with a view towards international harmonization. Mutation Research - Genetic Toxicology and Environmental Mutagenesis. 2015 November; 793: 101-106. DOI: 10.1016/j.mrgentox.2015.07.013.

    Sibonga JD, Spector ER, Johnston SL, Tarver WJ.  Evaluating bone loss in ISS astronauts. Aerospace Medicine and Human Performance. 2015 December 1; 86(12): 38-44. DOI: 10.3357/AMHP.EC06.2015. PMID: 26630194.

    Oganov VS, Grigoriev AI.  Mechanisms of human osteopenia and some peculiarities of bone metabolism in weightlessness conditions. Rossiĭskii fiziologicheskiĭ zhurnal imeni I.M. Sechenova / Rossiĭskaia akademiia nauk. 2012 March; 98(3): 395-409. PMID: 22645949. [Russian]

    Harm DL, Jennings R, Meck JV, Powell MR, Putcha L, Sams CF, Schneider SM, Shackelford LC, Smith SM, Whitson PA.  Invited Review: Gender issues related to spaceflight: a NASA perspective. Journal of Applied Physiology. 2001 November; 91(5): 2374-2383. PMID: 11641383.

    Pastushkova LK, Kireev KS, Kononikhin AS, Ivanisenko VA, Larina IM, Nikolaev EN.  Detection of renal and urinary tract proteins before and after spaceflight. Aviation, Space, and Environmental Medicine. 2013 August 1; 84(8): 859-863. DOI: 10.3357/ASEM.3510.2013. PMID: 23926664.

    Scheuring , Mathers , Jones JA, Wear .  Musculoskeletal Injuries and Minor Trauma in Space: Incidence and Injury Mechanisms in U.S. Astronauts. Aviation, Space, and Environmental Medicine. 2009 February 1; 80(2): 117-124. DOI: 10.3357/ASEM.2270.2009.

    Rykova MP.  Immune system of Russian cosmonauts after orbital space flights. Human Physiology. 2013 October 11; 39(5): 557-566. DOI: 10.1134/S0362119713050137.

    Cohen L, Vernon , Bergeron .  New molecular technologies against infectious diseases during space flight. Acta Astronautica. 2008; 63: 769-775. DOI: 10.1016/j.actaastro.2007.12.024.

    Matsumoto , Storch , Stolfi , Mohler , Frey , Stein TP.  Weight Loss in Humans in Space. Aviation, Space, and Environmental Medicine. 2011 Jun; 82(6): 615-621. DOI: 10.3357/ASEM.2792.2011.

    Jennings R, Murphy , Ware , Aunon SM, Moon , Bogomolov VV, Morgun VV, Voronkov YI, Fife CE, Boyars , Ernst .  Medical Qualification of a Commercial Spaceflight Participant: Not Your Average Astronaut. Aviation, Space, and Environmental Medicine. 2006; 77(5): 475-484. PMID: 16708526.

    Kerstman , Scheuring , Barnes , DeKorse , Saile .  Space Adaptation back pain: A Retrospective Study. Aviation, Space, and Environmental Medicine. 2012 January; 83(1): 2-7. DOI: 10.3357/ASEM.2876.2012. PMID: 22272509.

    Oganov VS, Baranov VS, Kabitskaya OE, Novikov V, Bakulin AV, Moskalenko MV, Aseev MV, Voitulevich LV.  Analysis of polymorphism of bone metabolism genes and evaluation of the risk of osteopenia in cosmonauts. Human Physiology. 2012 December 15; 38(7): 732-737. DOI: 10.1134/S0362119712070183. [Original Russian Text © V.S. Oganov, V.S. Baranov, O.E. Kabitskaya, V.E. Novikov, A.V. Bakulin, M.V. Moskalenko, M.V. Aseev, L.V. Voitulevich, 2010, published in Aviakosmicheskaya i Ekologicheskaya Meditsina, 2010, Vol. 44, No. 3, pp. 18–23.]

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Ground Based Results Publications

    Wilke D, Padeken D, Weber T, Gerzer R.  Telemedicine for the International Space Station. Acta Astronautica. 1999; 44(7-12): 579-581.

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ISS Patents

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Related Publications

    Becker JL, Souza GR.  Using space-based investigations to inform cancer research on Earth. Nature Reviews Cancer. 2013 May; 13: 315-327. DOI: 10.1038/nrc3507. PMID: 23584334.

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Related Websites

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image NASA Image:ISS017-E-017528 - Survey view of Crew Health Care System (CHeCS) Rack in the U.S. Destiny Laboratory.
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image NASA Image: ISS030E012609 - NASA astronaut Dan Burbank (foreground), Expedition 30 commander, and Russian cosmonaut Anton Shkaplerov, flight engineer, participate in a Crew Health Care System (CHeCS) medical contingency drill in the Destiny laboratory of the International Space Station. This drill gives crewmembers the opportunity to work as a team in resolving a simulated medical emergency onboard the space station.
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image NASA Image: ISS004E8540 - View of LAB1D4 rack containing Crew Health Care System (CHeCS) equipment in the Destiny U.S. Laboratory. Lockers are open to reveal the stowage locations for the Crew Contamination Protection Kits, Respiratory Support Pack (RSP), Emergency Kit, and Health Maintenance System (HMS) Defibrillator.
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image ISS018E043409 - Image of ISS transfer items (Radiation Area Monitor (RAM) hardware) added to the Crew Health Care System (CHeCS)/Photo TV Cargo Transfer Bag (CTB) for middeck locker MA16F, taken in the KSC Space Station Processing Facility (SSPF). CHeCS/Photo TV CTB packed for flight.
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