After 10 months housed at the International Space Station, the crew of the doomed Boeing Starliner spacecraft are soon expected make their long awaited return to Earth.

NASA astronauts Butch Wilmore and Suni Williams arrived at the ISS in June planning to stay for just 10 days as part of Boeing Starliner’s first crewed flight test. However, NASA learned the spacecraft had experienced multiple helium leaks and propulsion system issues so it returned empty in New Mexico last September.

Following months of planning, SpaceX launched its Dragon capsule Friday afternoon with its four Crew-10 members onboard. The four are scheduled to dock late Saturday night at the ISS’ port and passageway known as the Harmony module where they will undergo months of research.

The success of Friday’s launch paves the way for Wilmore’s and Williams to return as early as Wednesday, March 19 on a separate Dragon spacecraft already docked at the station. They will be joined by Crew-9 astronauts, NASA’s Nick Hague and Roscosmos’ Aleksandr Gorbunov who reached the station in September aboard a different Dragon with two empty seats.

Though Wilmore and Williams initially planned to return by the last Fourth of July, they have stuck at the station conducting science experiments, witnessing cosmos during spacewalks and connecting with Russian cosmonauts.

Here’s how they physically managed to go this long away from planet Earth.

What does being in space do to the body?

While in space, astronauts are at risk of experiencing physiological deterioration and exposure to higher levels of radiation. Additionally they must often endure isolated and confined environments for in Wilmore and Williams’s case long periods of time.

NASA said it gathers data from long-duration spaceflights to advance the safety of crewed missions.

Who checks astronauts health in space?

NASA astronauts undergo routine medical evaluations and are monitored by flight surgeons to ensure they are in good health while in space, the space agency told USA TODAY in November.

What about their resources up there?

NASA continuously ensures the space station is stocked with food, supplies, water, clothing and oxygen through routine supply missions about every three months.

What’s the longest someone has spent in space?

NASA astronaut and surgeon Frank Rubio holds the record for consecutive days aboard the ISS with 371 days straight.

He is proceeded by retired Army officer Mark Vande Hei at 355 days and engineer Scott Kelly at 340 days.

How do you sleep on the space station?

Crewmembers typically sleep for about eight hours a day.

Since the ISS doesn’t offer conventional beds, NASA astronauts sleep in specially designed sleeping bags that can attach to walls in what’s called microgravity rest.

Do astronauts exercise in space?

ISS crew members and must physically exercise about two hours every day to protect their muscles and bones that are counteracted by the absence of Earth’s gravity.

Contributing: Eric Lagatta, Jennifer Borresen, George Petras, Javier Zarracina, USA TODAY

(This article was updated to include video.)