CAPE CANAVERAL, Fla. – Space travel is far from one-size-fits-all: Missions to different destinations—whether low Earth orbit, the Moon, or Mars—present unique challenges, especially when it comes to radiation exposure.
Astronauts aboard the upcoming Artemis II mission will travel beyond Earth’s protective magnetic field, exposing them to what experts call galactic cosmic radiation, according to aerospace physician Emmanuel Urquieta with UCF. Further explaining, this type of radiation poses significant health risks because it’s “outside of the magnetic protection of the Earth.”
As the department Vice Chair, Urquieta’s knowledge in this field is expansive, having also served as the Chief Medical Officer at the NASA-funded Translational Research Institute for Space Health.
He explained that for long-duration missions to the Moon, this exposure could increase the risk of cancer, cognitive decline, and even severe DNA mutations. However, Artemis II is expected to last only about 10 days, limiting those risks.
Urquieta said advancements in technology over the past five decades are also helping scientists better understand how space affects the human body, especially with researchers now able study biological changes at a cellular level, including shifts in proteins, hormones, and genes—capabilities that were not available during earlier space missions.
Despite improvements in spacecraft design, the physical toll of space travel remains significant. Inside the massive rocket—weighing roughly 11 million pounds—astronauts are shielded during launch. But once in microgravity, the human body reacts quickly.
“Most astronauts in space get nauseous and vomit pretty much right away,” Urquieta said.
While those symptoms typically subside after a few days, other challenges emerge. Bone density and muscle mass begin to decline in zero gravity after a few days.
On the International Space Station, astronauts counteract this by exercising for about two hours a day.
However, the Orion spacecraft used for Artemis missions is much smaller and lacks the same exercise capabilities.
As a result, astronauts returning from the mission may be physically weakened and could require assistance—potentially even stretchers—after splashdown.
But, big picture, as NASA prepares for a new era of lunar exploration, the Artemis II moon orbit will serve as a critical test of both human endurance and the technologies designed to keep astronauts safe beyond Earth’s orbit.
You can watch Dr. Urquieta’s full interview below.