BEIJING, Aug. 8 -- The Shenzhou-18 crew on board China's orbiting space station conducted a fire alarm test recently, evaluating the performance of the fire detection sensors within the three-module craft.

The China Manned Space Agency has released video updates from space, showing the three taikonauts using specialized tools to activate temperature and smoke detectors, which in turn triggered fire alarms for lighting and instruments.

The trio also collected blood samples. In addition to routine blood examinations conducted in orbit, some samples will be preserved at low temperatures and transported back to Earth after the mission for further medical study.

They underwent a range of medical checks related to blood pressure, heart rate and lung function, according to the space agency.

The Shenzhou-18 crew have completed more than half of their six-month space journey since they were launched in late April. They performed two spacewalks and several scientific experiments in orbit.