Planetary Transportation Systems (PTS), formerly known as PTScientists and Part-Time Scientists, is a Berlin-based aerospace company. They developed the robotic lunar lander "ALINA" and seek to land on the Moon with it. They became the first German team to officially enter the Google Lunar X-Prize competition on June 24, 2009, but failed to reach the finals in 2017 for lack of a launch contract. During the summer of 2019, the company filed for bankruptcy, and the ALINA project was put on hold. In July 2021, PTS was selected with ArianeGroup to build ESA's ASTRIS kick-stage.