International Space Station Crew Lands Safely On Steppe Of Kazakhstan (SLIDESHOW)

The Expedition 39 crew touched down on Earth Tuesday after spending 188 days in space.

The astronauts landed on the steppe of Kazakhstan at 7:58 a.m. Kazakh time. Helicopters carrying NASA personnel rushed to the site to assist the crew and perform medical examinations, a NASA news release reported.

The landing means Expedition 40 will begin under the command of NASA astronaut Steve Swanson.

On Monday afternoon the crew said one last goodbye to the ISS and boarded the Soyuz TMA-11M spacecraft. The craft also carried back microbiome samples from a study that looked at how space travel affects the immune system (the microbes had lived in the human body).  The crew took the samples periodically from their own bodies.

"During Expedition 39, the crew participated in a variety of research, including a human immune system activation and suppression study and a protein crystal growth research study looking for proteins responsible for Huntington's disease and other neurodegenerative conditions. The crew also installed a new plant growth chamber designed to expand in-orbit food production capabilities," NASA stated in the news release.

While in space the team also saw the delivery of cargo from three different spacecrafts, a" Russian Progress resupply vehicle, Orbital Sciences' Cygnus cargo ship and SpaceX Dragon," the news release reported.

Flight Engineer Rick Mastracchio performed three spacewalks during the Expedition. The first two spacewalks were to fix faulty cooling pumps and the final walk was to replace backup computer relay box that had failed.

Swanson and his crewmates Alexander Skvortsov and Oleg Artemyev of Roscosmos will operate the space station for the next three weeks until three additional crew members arrive. The new members of the expedition will be "Reid Wiseman of NASA, Max Suraev of Roscosmos and Alexander Gerst of the European Space Agency," the news release reported.