Astronaut Scott Kelly, whose feet are firmly planted on Earth these days, is still looking skyward: toward Mars.  

Kelly served as a witness for the House Science, Space and Technology Committee Subcommittee’s discussion on safety for a Red Planet mission.  

“We can be successful, whether that’s going to Mars or curing cancer, if that’s what we decide to do,” Kelly said. “The physical challenges, that would be the number one concern I would have.”  

Kelly, who just returned from space on March 1, retired in April.  

He said two options to protect astronauts on a Mars mission would be to get them their faster or limit their exposure to radiation while en route.  

“Much attention is paid to the risks astronauts face while launching abroad rockets or returning to Earth in a giant fireball,” Kelly said. “Much less attention is given to the other risks astronauts face which are much more insidious but potentially just as fatal.”  

Kelly set the record for the total accumulated number of days spent in space by an American astronaut in October. He is a veteran of four space flights and on his most recent mission, he spent 340 consecutive days in away from Earth’s gravity. He pointed to the high levels of radiation and carbon dioxide astronauts are exposed to and said how he felt after the 340-day trip to the Space Station compared to after his 159-day trip.  

“Being in space for twice as long didn’t mean that I lost twice as much bone mass, it was pretty similar,” he said. “Although, how I felt when I got back was much different.”  

The panel discussed how he had a rash and flu-like symptoms.  

Kelly’s twin brother, Mark Kelly, is also a former astronaut and his sister-in-law is former Arizona Congresswoman Gabby Giffords.