The structure and function of the kidneys is altered by space flight, with galactic radiation causing permanent damage that would jeopardize any mission to Mars, according to a new study led by researchers from UCL.

The study, published in Nature Communications, is the largest analysis of kidney health in space flight to date and includes the first health dataset for commercial astronauts. It is published as part of a Nature special collection of papers on space and health.

Researchers have known that space flight causes certain health issues since the 1970s, in the years after humans first traveled beyond Earth's magnetic field, most famously during the first moon landing in 1969. These issues include loss of bone mass, weakening of the heart and eyesight, and development of kidney stones.

It is thought that many of these issues stem from exposure to space radiation, such as solar winds from the sun and Galactic Cosmic Radiation (GCR) from deep space, which the Earth's magnetic field protects us from on Earth. As most manned space flights take place in Low Earth orbit (LEO) and receive partial protection from Earth's magnetic field, only the 24 people who have traveled to the moon have been exposed to unmitigated GCR and only for a short time (six to 12 days).

As long as humans have been traveling into space, astronauts have experienced significant health effects from the extreme conditions of space flight, notably the reduction of gravity.

Two Buck scientists led a team that has revealed for the first time how the lack of gravity affects the cells of the immune system at single cell resolution. The co-senior authors, along with Christopher E. Mason, Ph.D. of Weill Cornell Medical College, Associate Professor David Furman, Ph.D. and Associate Professor Daniel Winer, MD, have published an extensive survey of how gravity affects immune cells, and the identification of "space nutraceuticals" to counter aberrant effects of microgravity on these cells. The work is published in Nature Communications

"We show how simulated microgravity shapes immune cells and how the changes in force alter the cells' function at the single cell level," said Winer. "This level of resolution is new and exciting in understanding the effects of microgravity on cells."

Using cells in simulated microgravity, combined with data from space flight from astronauts and mice on the International Space Station, the researchers created a complete picture of how the different cells of the immune system in the peripheral blood are shaped by reduced gravity.