Operational Considerations for Crew Fatality on the International Space Station.

BACKGROUND: While catastrophic spaceflight events resulting in crew loss have occurred, human spaceflight has never suffered an on-orbit fatality with survival of other crewmembers on board. Historical plans for management of an on-orbit fatality have included some consideration for forensic documentation and sample collection, human remains containment, and disposition of remains; however, such plans have not included granular detailing of crew or ground controller actions. The NASA Johnson Space Center Contingency Medical Operations Group, under authority from the Space and Occupational Medicine Branch, the Space Medicine Operations Division, and the Human Health and Performance Directorate, undertook the development of a comprehensive plan, including an integrated Mission Control Center response for flight control teams and Flight Surgeons for a single on-orbit crew fatality on the International Space Station (ISS) and subsequent events. Here we detail the operational considerations for a crew fatality should it occur during spaceflight onboard the ISS, including forensic and timeline constraints, behavioral health factors, and considerations for final disposition of decedent remains. Future considerations for differential survival and crewmember fatality outside of low-Earth orbit operations will additionally be discussed, including consideration of factors unique to planetary and surface operations and disposition limitations in exploration spaceflight. While the efforts detailed herein were developed within the constraints of the ISS concept of operations, future platforms may benefit from the procedural validation and product verifications steps described. Ultimately, any response to spaceflight fatality must preserve the goal of handling decedent remains and disposition with dignity, honor, and respect.Stepaniak PC, Blue RS, Gilmore S, Beven GE, Chough NG, Tsung A, McMonigal KA, Mazuchowski EL II, Bytheway JA, Lindgren KN, Barratt MR. Operational considerations for crew fatality on the International Space Station. Aerosp Med Hum Perform. 2023; 94(9):705-714.

Remains Containment Considerations for Death in Low-Earth Orbit.

BACKGROUND: Maintenance and disposition of decedent remains during spaceflight require the isolation of biohazardous products of decomposition in microgravity and in the absence of refrigeration. Containment and isolation options would preferably offer sufficient time to enable crew and ground support teams to determine appropriate disposition of remains and even potentially return remains to the Earth. The pilot study described herein undertook an effort to develop a postmortem containment unit for the isolation and maintenance of decedent remains in a microgravity environment.METHODS: Commercial off-the-shelf containment units were modified to meet the needs of a microgravity spaceflight environment and to offer the best likelihood of successful containment and management of remains. A subsequent evaluation of modified containment unit performance was undertaken utilizing human cadavers, with measurement and analysis of volatile off-gassing over time followed by impact testing of the units containing cadaverous remains in a simulated spaceflight vehicle seat.RESULTS: Modifications were implemented without significant negative design impact. Failure was observed in one modified unit after 9 d and attributed to improper filter application. The remaining unit successfully contained remains beyond the intended endpoint of the study.DISCUSSION: These pilot efforts offer important insight into the development of effective postmortem containment options for future spaceflight. Further study is needed to ensure repeatability of the findings and to further characterize the failure modes of the modified units evaluated, the impact of microgravity conditions, and the identification of additional modifications that would improve remains disposition.Houser T, Lindgren KN, Mazuchowski EL II, Barratt MR, Haines DC, Jayakody M, Blue RS, Bytheway JA, Stepaniak PC. Remains containment considerations for death in low-Earth orbit. Aerosp Med Hum Perform. 2023; 94(5):368-376.

Medical monitoring during the NASA Artificial Gravity-Bed Rest Pilot Study.

The NASA artificial gravity-bed rest pilot study (AGPS) was designed to investigate the efficacy of daily exposure to a +Gz acceleration gradient for counteracting the physiologic decrements induced by prolonged bed rest. Test subjects were continuously monitored by a physician for signs and symptoms of pre-syncope, motion sickness, and arrhythmias while on the centrifuge. In this article, we have summarized the medical monitoring observations that were made during the AGPS and included an assessment of the relative usefulness of the information provided by the various monitoring tools in making a decision to terminate a centrifuge spin.

Physiologic response to moderate altitude exposure among infants and young children.

Substantial numbers of children are exposed to moderate altitude while traveling to mountain resorts with their families. Although there has been extensive study of the adult physiologic response to altitude exposure, few studies of infants and young children exist. This investigation examines the acute physiologic responses to moderate altitude exposure among young children and the relationship of these responses to the development of acute mountain sickness (AMS). Children 3 to 36 months old participated in the prospective observational study, which included baseline measurements at 1610 m and measurements after a 24-h exposure to 3109 m. Measurements included pulse and respiratory rate, end-tidal CO(2), arterial oxygen saturation (pulse oximetry), cerebral tissue oxygenation (St(O2)) by near-infrared spectroscopy, middle cerebral artery resistive index by transcranial Doppler, lateral ventricle volumes (ultrasound), and clinical evaluation for the presence of acute mountain sickness (Children's Lake Louise Score). Twenty-four children (13 girls and 11 boys, age 14.5 +/- 10.2 months) participated. After acute exposure to 3109 m, these children showed an increase in respiratory rate from 45 +/- 13 to 51.9 +/- 15 breaths/min (p < 0.008), accompanied by a decrease of end-tidal CO(2) from 31 +/- 3 to 28 +/- 2 mm Hg (p < 0.001) and a reduction of arterial oxygen saturation from 95 +/- 2 to 91 +/- 2% (p < 0.001). St(O2) also decreased from 78 +/- 8 to 67 +/- 13% (p < 0.001), and this reduction appeared to be related to age (r = 0.58, p < 0.05), with lower saturations found in younger children. No evidence of increased intracranial pressure, as assessed by middle cerebral artery resistive index, was seen during ascent. Seven subjects developed symptoms of AMS; however, no relationship was found between the physiologic changes observed and the presence of symptoms. Ascent from 1610 to 3109 m resulted in tachypnea, relative hypoxia, hypocapnia, and a reduction in cerebral tissue oxygenation (St(O2)). The reduction in St(O2) appeared to be related to age, with infants appearing to be the most susceptible to cerebral tissue oxygen desaturation at high altitude. No relationship appears to exist between the presence of AMS and the physiologic measurements.