15, 2012, Acaba was one of three crew members launching from Kazakhstan aboard the Soyuz TMA-04M spacecraft to the International Space Station. He and his fellow crew members, Gennady Padalka and Sergei Revin, arrived and docked with the space station two days after launch, on May 17 at 4:36 UTC. Acaba, along with Padalka and Revin, returned to Earth on September 17, 2012, after nearly 125 days in space. Between space missions Acaba served as the Branch Chief of the International Space Station Operations branch. The office is responsible for mission preparation and on-orbit support of space station crews. Until being selected as flight engineer for Expedition 54\Expedition 55 Acaba served as Director of Operations Russia in Star City supporting crew training in Soyuz and Russian Segment systems. In September 2019 Acaba served as cavenaut in ESA CAVES training (between Italy and Slovenia) spending six nights underground simulating a mission exploring another planet. Expedition 53/54 In 2017 it was announced that Acaba would be returning to the ISS for his third mission, onboard Soyuz MS-06. The Soyuz vehicle was originally slated to launch with a crew of 2, due to the Russian crew cuts on the ISS for 2017, however, at short notice, it was decided that the 3rd seat would be filled by an experienced astronaut and would be funded by Roscosmos to cancel out owed debts. Acaba's backup for the mission was Shannon Walker, who was scheduled to fly as prime crew on Soyuz MS-12 as part of Expedition 59/60, although as of December 2018, she is not assigned to that crew Acaba launched on Soyuz MS-06 on September 12, 2017, performing a 6-hour rendezvous with the ISS. On October 20, 2017, Acaba and Randy Bresnik performed an EVA to continue with the lubrication of the new end effector on the robotic arm, and to install new cameras. The duration was 6 hours and 49 minutes. During the mission Acaba's home in Houston was flooded by Hurricane Harvey and Hurricane Maria struck his native Puerto Rico. Statistics Chief of the Astronaut Office In 2023, Acaba became Chief of the Astronaut Office at NASA. He replaced Drew Feustel who was acting Chief of the Astronaut Office. Recognition On March 18, 2008, Acaba was honored by the Senate of Puerto Rico, which sponsored his first trip to the Commonwealth of Puerto Rico since being selected for space flight. During his