Why Astronaut Trio Is Taking a Longer Path to the International Space Station

The most direct route takes six hours.

— -- You could say they're taking the long way there.

At the ISS, the group will spend four months conducting "more than 250 science investigations in fields such as biology, Earth science, human research, physical sciences and technology development," according to NASA.

Rubins, a microbiologist, will stay at the space station until October.

"I think it's going to be amazing to see how the world of microbiology, molecular and cellular biology and human physiology is massively changed by microgravity," she told ABC News before her launch.

"This is the only laboratory we have as humans to study gravity as a variable," she said. "There's a world of insights to be gained into human health and disease by understanding how gravity and space radiation influence biology."