BEIJING, 0ct. 14 (Xinhuanet) -- The Shenzhou-6 spacecraft underwent its first orbit maintenance operation early Friday morning to restore the vessel to its original trajectory.

The operation began at 5:56 a.m. Beijing time Friday during the spacecraft's 30th circle flight around the Earth and successfully restored the slightly deviated vessel to its original trajectory acouple of seconds later, according to Beijing Aerospace Command and Control Center.

The spacecraft, which blasted off Wednesday morning with two astronauts onboard, had slightly deviated from its designed orbit and is moving a little closer to the Earth due to gravity.

Shenzhou-6, China's second manned space flight, is designed to travel in a circular orbit 343 kilometers above the Earth after the orbit shift from an elliptical orbit in its fifth circle around the Earth.

Experts said the maintenance is a normal technical operation and similar tasks are possible in the future in accordance with the spacecraft's orbiting situations.

Shenzhou-6 is expected to travel in space for up to five days, exceeding the time spent in space during China's first manned flight in 2003, when astronaut Yang Liwei aboard Shenzhou-5 spacecraft stayed in space for nearly 21.5 hours.