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.

Thyroid function changes related to use of iodinated water in the U.S. Space Program

BACKGROUND

The National Aeronautics and Space Administration (NASA) has used iodination as a method of microbial disinfection of potable water systems in U.S. spacecraft and long-duration habitability modules. A review of thyroid function tests of NASA astronauts who had consumed iodinated water during spaceflight was conducted.

METHODS

Thyroid function tests of all past and present astronauts were reviewed. Medical records of astronauts with a diagnosis of thyroid disease were reviewed. Iodine consumption by space crews from water and food was determined. Serum thyroid-stimulating hormone (TSH) and urinary iodine excretion from space crews were measured following modification of the Space Shuttle potable water system to remove most of the iodine.

RESULTS

Mean TSH significantly increased in 134 astronauts who had consumed iodinated water during spaceflight. Serum TSH, and urine iodine levels of Space Shuttle crewmembers who flew following modification of the potable water supply system to remove iodine did not show a statistically significant change. There was no evidence supporting association between clinical thyroid disease and the number of spaceflights, amount of iodine consumed, or duration of iodine exposure.

CONCLUSIONS

It is suggested that pharmacological doses of iodine consumed by astronauts transiently decrease thyroid function, as reflected by elevated serum TSH values. Although adverse effects of excess iodine consumption in susceptible individuals are well documented, exposure to high doses of iodine during spaceflight did not result in a statistically significant increase in long-term thyroid disease in the astronaut population.

Acyclovir therapy of varicella-zoster virus infections in immunocompromised patients

In a randomized, placebo-controlled, double-blind trial of intravenous acyclovir in the treatment of varicella zoster virus (VZV) infections, 8 of 20 immunocompromised children with varicella received acyclovir (500 mg/m2/dose three times daily for 7 days). There was no significant difference in skin healing between the acyclovir and placebo groups although there was a significant reduction in the incidence of development of pulmonary involvement during acyclovir treatment. Nineteen out of 34 patients received vidarabine (10 mg/kg/day for 5 days). Vidarabine significantly shortened the duration of new vesicle formation. Both drugs significantly reduced the incidence of visceral varicella, the most serious complication of VZV infection. An open trial also concluded that early treatment of varicella in these patients is essential. Of the 94 patients with zoster infection, 52 received acyclovir (500 mg/m2/dose infused over one hour three times daily for 7 days). Acyclovir recipients healed more rapidly, had fewer days of pain and shorter duration of viral shedding compared with placebo patients. The most important finding was that acyclovir significantly protected against progression of zoster as defined by development or progression of cutaneous dissemination and development of visceral zoster. Vidarabine seemed to be equally effective in this respect. The likelihood of cutaneous dissemination is related to the nature of the underlying condition. The in vitro sensitivity of VZV isolates from patients with second episode VZV infection during the trial did not change appreciably which suggests that VZV does not become resistant to acyclovir during therapy.