China has successfully launched three cube satellites, or CubeSats, that are expected to help track civil aircraft and ships to avoid tragedies like the missing Malaysia Airlines Flight MH370.

The three CubeSats, part of a mission coded STU-2, were launched on Sept 25 and have entered their designed orbit, said the mission's chief designer, Wu Shufan.

The three spacecraft are equipped with polar observation cameras, as well as automatic identification system receivers, to capture information from ships, and automatic dependent surveillance-broadcast receivers, for messages sent from civil aircraft.

The flight system was developed to be installed on civil aircraft and transmit the flight's position, height, speed, direction and other information automatically every second to receivers on the ground or in the air. Currently more than 70 percent of aircraft have such systems installed.

As of Sept 28, the STU-2 CubeSats had collected hundreds of thousands of messages from more than 12,400 aircraft flying within receiving range. The paths and traffic flow of civil flights within the satellites' monitoring area can be collected in real time.

"If there are enough satellites in orbit to cover a region wide enough, a specific flight could be tracked, and that may help with spotting and search in cases like MH370," Wu said.

Like a Rubik's cube, a CubeSat is a satellite composed of smaller cubic units. A CubeSat may contain three or more units.

Compared with other satellites, cube spacecraft are generally smaller and lighter.

Wu said the three STU-2 CubeSats weigh only 6.8 kilograms total.