In space, no one can hear you sneeze – but that hasn’t stopped a team of boffins researching exactly what happens when an astronaut gets a case of the sniffles, and why. The key takeaway, should you find yourself on board a space station and in need of a tissue: maybe skip the spacewalk.
“Astronauts are typically among the fittest individuals on the planet, yet this study shows that even they experience substantial sinonasal complaints in space,” Dr Masayoshi Takashima, project lead and chair of the department of otolaryngology at Houston Methodist Hospital, said of the work, which analysed data provided by the Lifetime Surveillance of Astronaut Health (LSAH) Programme at NASA’s Johnson Space Center.
“Imagine what happens when civilians with preexisting conditions start travelling to space.”
The study looked at 754 “medical events” experienced by a total of 71 astronauts visiting the International Space Station between 2000 and 2019. Of these, 85 percent experienced at least one “sinonasal complaint” – far higher than you would expect from a healthy sample group – with 75 percent also reporting nasal congestion.
Unlike the case of German measles which famously saw Thomas K “Ken” Mattingly replaced by John L “Jack” Swigert as the Command Module Pilot of Apollo 13 just three days prior to launch, these snotty problems aren’t usually the result of viral or bacterial infection – instead being simply a side-effect of being in space, with the lack of gravity in orbit playing havoc with the body’s ability to drain fluids.
A bigger problem for NASA and others operating outside the Earth’s atmosphere: the symptoms can have a measurable impact on crew performance, and are worsened during extra-vehicular activity (EVA) – spacewalks. The pressure difference between the space station and the crew’s space suits was found to increase congestion, cause barotrauma injuries to ears and sinuses, and dysfunction in the Eustachian tubes – resulting in pain and muffled hearing.
No mention was made in the study regarding stuffed-up astronauts’ potential to turn a productive sneeze into propulsion in place of the iconic Manned Manoeuvring Unit (MMU), a product of the Space Shuttle programme which uses jets of nitrogen released through a total of 24 nozzles – rather than snot released through two nozzles – to guide an astronaut’s movements in free space.
“This is about maintaining peak performance,” Takashima added in a statement on the paper’s publication. “If you’re not sleeping well because you can’t breathe, your cognitive function, reaction time and mission performance can suffer, and those things are absolutely critical in space.”
A bigger problem than having to haul a hundred boxes of Kleenex into orbit every supply run, though, is in the performance of traditional remedies off-planet. “Are earth-based medications for congestion and symptom relief effective in the microgravity environment,” the researchers asked, a question not directly addressed in the study which recorded pseudoephedrine and oxymetazoline as the most commonly used medicines for an orbital bunged-up nose.
“We foresee potential in procedural strategies such as radiofrequency turbinate reduction to decrease expansile tissue volume,” the study suggested.
“Current NASA standards further affirm that complicated sinonasal history such as enlarged turbinates or obstructions to nasal breathing are disqualifying ‘unless medically or surgically corrected with normal function restored,’ supporting the use of such interventions. Given the expansion of spaceflight to a broader population, we believe these options will be considered in the years to come for individuals with preexisting sinonasal conditions.”
The study has been published in the journal Laryngoscope Investigative Otolaryngology under open-access terms. ®