CAPE CANAVERAL, Fla. — NASA astronauts Butch Wilmore and Suni Williams are preparing to come back to Earth Tuesday after their eight-day test mission to the International Space Station turned into 286 days.

Some may be concerned about Wilmore and Williams’ health due to their unexpected long stay in space, but adjustments back to Earth like this are not unusual, says a NASA official.

The agency has a history of assigning astronauts to long duration missions, some more than a year long.

“What we have seen with other long duration astronauts, some of them staying a year, there is a little bit more of an adjustment, but it’s really not as dramatic as you might think,” NASA public affairs official Steve Sicloff.

Frank Rubio is the record holder for consecutive days on board the ISS with 371 days in a row.

The physical effects most astronauts face, according to NASA studies, is a loss of bone density of about “1% to 1.5% of mineral density per month during spaceflight.”

However, even if those issues aren’t fully corrected through rehab, their “risk of fracture is not higher.”

The astronauts also exercise daily and eat regularly to keep up their strength, as without it they could “lose muscle mass in microgravity faster than they would on Earth.”

Williams says the return home will be bittersweet.

“My time on board is coming to a close, soon I’ll be heading home, as you may be aware I’ve been here on board a bit longer than originally planned, back in June, but I’ve always said ISS is my happy place so it’s been natural for me to make the most of being here,” she said.

The undocking happened at 1:05 a.m., Tuesday.

It is not known exactly where the splashdown will take place since NASA is still currently figuring out the weather conditions at various destinations off of Florida’s coast.