Expedition 39 was a mission to the International Space Station (ISS) that took place from March to September 2014. The crew consisted of six astronauts, including NASA astronauts Steve Swanson, Rick Mastracchio, and ESA astronaut Alexander Gerst. Their primary objectives included conducting scientific research and performing maintenance on the ISS. During the mission, the crew carried out over 150 experiments in various fields such as biology, physics, and technology. They also participated in spacewalks to upgrade the station's systems and enhance its capabilities for future missions. Expedition 39 contributed to the ongoing research and international collaboration in space exploration.