Nearly two years after the conclusion of its space shuttle program left Americans wondering what would become of the spacefaring dreams of decades past, NASA has sought the advice of health and ethics experts for protecting astronauts on its "next generation" of long duration and exploration-class human spaceflights.
Such missions, including extended stays on the International Space Station and flights to Mars, have higher risks and are unlikely to meet the space agency's current health standards. Options not on the table, according to the Institute of Medicine (IOM) committee report commissioned by NASA and released April 2, are relaxing those standards or adopting new standards specifically for long duration or exploration missions. The report calls both potential practices arbitrary and "ethically unacceptable," and provides ethical guidelines for decision-making about if and when rare exceptions to existing standards should be made. The IOM notes that the committee did not make conclusions or recommendations about the value or advisability of future human spaceflight.
Jeffrey Kahn, PhD, MPH, of the Johns Hopkins Berman Institute of Bioethics and chair of the IOM committee, says "Astronauts put their lives and health at great risk for their country and humankind. Our report builds on NASA's work and confirms the ethical imperative to protect astronauts' health, while fulfilling the agency's mission of exploration." The report recommends changes in policy regarding lifetime healthcare and monitoring of astronauts, and endorses continued provisions for the privacy and confidentiality of their health data.
First, the committee says, NASA should decide whether it is acceptable to risk astronaut health and safety for missions that could exceed the health standards. If NASA decides such missions are ethically acceptable, it must then determine the process and criteria for granting exceptions.
If a mission is deemed ethically acceptable, the third decision level focuses on the selection of the crew for the mission and an astronaut's decision to participate on that mission. NASA should ensure both "equality of opportunity" to participate in these missions, and that participation is voluntary. The report makes clear that astronauts must be fully informed of all risks as they are known - before, during and even after long duration and exploration missions.
Examples of the health risks astronauts face, covered by NASA's current health standards, are effects of microgravity environments such as vision impairment, bone loss, behavioral changes and lifetime cancer risks due to radiation exposure. Longer and more distant spaceflight would increase these risks, as well as additional uncertain and "perhaps unforeseeable" risks, the report notes.
"From its inception, space exploration has pushed the boundaries and risked the lives and health of astronauts," Kahn says. "Determining where those boundaries lie and when to push the limits is complex. NASA will continue to face decisions as technologies improve and longer and farther spaceflights become feasible. Our report builds upon NASA's work and compiles the ethics principles and decision-making framework that should be an integral part of discussions and decisions regarding health standards for long duration and exploration spaceflight."