Space medicine
The spaceflight environment poses many unique stressors to the human body, including G forces, microgravity, unusual atmospheres such as low pressure or high carbon dioxide, and space radiation.
This expertise is additionally used to inform vehicle systems design to minimize the risk to human health and performance while meeting mission objectives.
[2][3] In October 2015, the NASA Office of Inspector General issued a health hazards report related to space exploration, including a human mission to Mars.
[4][5] Hubertus Strughold (1898–1987), a former Nazi physician and physiologist, was brought to the United States after World War II as part of Operation Paperclip.
The aeromedical library at Brooks AFB was named after him in 1977, but later renamed because documents from the Nuremberg War Crimes Tribunal linked Strughold to medical experiments in which inmates of the Dachau concentration camp were tortured and killed.
In 1949, A.M. Vasilevsky, the Minister of Defense of the USSR, gave instructions via the initiative of Sergei Korolev to NIIAM to conduct biological and medical research.
[10] After several years of failed animal recoveries, an Aerobee rocket launch in September 1951 was the first safe return of a monkey and a group of mice from near space altitudes.
[14] Ham's vital signs were monitored and collected throughout the 16 minute flight, and used to develop life support systems for later human astronauts.
[15] Rocket-powered aircraft North American X-15 provided an early opportunity to study the effects of a near-space environment on human physiology.
Substantial animal testing proved beyond a reasonable doubt to NASA engineers that spaceflight could be done safely provided a climate controlled environment.
The understanding of high and low G environments was well documented and the effects of isolation had been addressed with Gemini and Apollo having multiple occupants in one capsule.
[20] In October 2018, NASA-funded researchers found that lengthy journeys into outer space, including travel to the planet Mars, may substantially damage the gastrointestinal tissues of astronauts.
Eliminating inert atmospheric components such as nitrogen allows the astronaut to breathe comfortably, but also have the mobility to use their hands, arms, and legs to complete required work, which would be more difficult in a higher pressure suit.
This occurs due to a rapid reduction in ambient pressure causing the dissolved nitrogen to come out of solution as gas bubbles within the body.
[28][29] DCS may result from inadequate or interrupted pre-oxygenation time, or other factors including the astronaut's level of hydration, physical conditioning, prior injuries and age.
Other risks of DCS include inadequate nitrogen purge in the EMU, a strenuous or excessively prolonged EVA, or a loss of suit pressure.
[34][35] One would be predisposed by a pre-existing upper respiratory infection, nasal allergies, recurrent changing pressures, dehydration, or a poor equalizing technique.
[40] Astronauts in space have weakened immune systems, which means that in addition to increased vulnerability to new exposures, viruses already present in the body—which would normally be suppressed—become active.
Until then, NASA's astronauts must rely on a medication called Midodrine (an “anti-dizzy” pill that temporarily increases blood pressure), and/or promethazine to help carry out the tasks they need to do to return home safely.
[61][62][63][64][67] On December 31, 2012, a NASA-supported study reported that human spaceflight may harm the brain of astronauts and accelerate the onset of Alzheimer's disease.
[68][69][70] On 2 November 2017, scientists reported that significant changes in the position and structure of the brain have been found in astronauts who have taken trips in space, based on MRI studies.
[67][76][77][78][79] On 11 June 2024 researchers at the University College of London's Department of Renal Medicine reported that "Serious health risks emerge (with respect to the kidneys) the longer a person is exposed to Galactic Radiation and microgravity.
[86] Astronauts exhibit asynchronized cortisol rhythmicity, dampened diurnal fluctuations in body temperature, and diminished sleep quality.
Conducting medical research in space alone will not provide humans with the depth of knowledge needed to ensure the safety of inter-planetary travelers.
[91] The following pharmacological and environmental strategies have been investigated in the context of sleep in space: Ultrasound is the main diagnostic imaging tool on ISS and for the foreseeable future missions.
It is currently being used to look at the eyeball and the optic nerve to help determine the cause(s) of changes that NASA has noted mostly in long duration astronauts.
Future exploration class missions will need to be autonomous due to transmission times taking too long for urgent/emergent medical conditions.
With the additional lifting capability presented by the Space Shuttle program, NASA designers were able to create a more comprehensive medical readiness kit.
[106] John Glenn, the first American astronaut to orbit the Earth, returned with much fanfare to space once again on STS-95 at 77 years of age to confront the physiological challenges preventing long-term space travel for astronauts—loss of bone density, loss of muscle mass, balance disorders, sleep disturbances, cardiovascular changes, and immune system depression—all of which are problems confronting aging people as well as astronauts.
"The involved crewmember is endangered because of mission stress and the lack of complete treatment capabilities on board the spacecraft, which could result in the manifestation of more severe symptoms than those usually associated with the same disease in the terrestrial environment.
