The Shenzhou-18 mission crew aboard China's orbiting space station conducted a fire alarm test to evaluate the performance of fire detection sensors inside the three-module spacecraft.The China Manned Space Agency released video updates from space, showing the three astronauts using specialized tools to activate heat and smoke detection sensors, which in turn triggered a fire alarm for light and equipment.The three astronauts also collected blood samples. Some of the samples will be preserved at low temperatures and transported back to Earth after the mission for further medical study.The astronauts underwent a series of medical tests related to blood pressure, heart rate and lung function, according to the space agency.The Shenzhou-18 crew has completed more than half of its spaceflight since its launch in late April, and has also conducted two spacewalks and several scientific experiments in orbit.Source: Qatar News Agency