Information + Clues

Future exploration missions for periods of time that could range from months to years lead to inevitable mental changes. This is caused by isolation, distance from Earth, confinement, radiation, and altered gravity. These severe changes in the environment can lead to cognitive or behavioral conditions, affecting health and performance. Some examples of late-emerging cognitive and behavioral issues include Alzheimer’s, dementia, and clinical depression. Such health conditions were reported on multiple missions, commonly those of long duration. The estimated ISS incidence of behavioral health symptoms has been averaged around 0.62 person-year, but this value has not been confirmed. Research involving animals suggests that short-term cognitive decrements can be caused by radiation. If these aren’t mitigated or undetected, the development of psychiatric disorders could start.

Adverse health outcomes and decrements in performance during missions can occur due to medical conditions. These can occur in-flight or post flight. There has never been loss of crew life due to this; however, several evacuation or early terminations have. Minimal long term health impacts have been detected from spaceflight exposure. The need for increasing crew independence in the future allows the possibility of adverse outcomes linked with deficiencies, meaning that the crew are unable to respond to malfunctions and perform critical procedures. Such malfunctions occur at a rate of 1.7 times a year and average over 3-4 times a year over the lifetime in the burn phase for a vehicle (not including EVA data which would increase the incident rate). In the design reference categories, mitigation and standard refinement is required for Lunar Orbital while mitigation alone is required for the surface and/or Mars.

Because the crew isn’t used to the altered sense of gravity in space, they will have an altered sense of sensorimotor (involving sensory and motor functions) and vestibular (involving the inner ear and sense of balance) function. This can cause motion sickness, spatial disorientation, decrease in postural control, a decrease in locomotion (the ability to move from a place to another), and a decrease in fine motor skills. This will lead to a performance decline manual in manual and vehicle control and egress (leaving and entering the vehicle). Also, the skeletal changes that occur during flight can lead to bone fractures and the weakening of bones. Fractures can occur after spaceflight, and also the mitigation of early onset osteoporosis (weak and brittle bones) is required during and after spaceflight.

The spaceflight environment can contribute to cardiovascular deconditioning, dysfunction, and remodeling. This leads to the possibility that crews perform at a limited level and cause negative cardiovascular health effects during/after spaceflight. The experience of gravity alters blood volume, flow, pressure distribution, etc. Space radiation and long term weightlessness effects are unknown, they can lead to cardiovascular structural and functional changes

Due to the range of different types of dynamic loads transferred to the crew via the space vehicle, there is a likelihood of loss of crew or crew injury during the departure and landing of the flight. We also do not know how the risk of injury is associated with vehicle landings.