BEIJING - China has successfully launched three cube satellites (CubeSats), which are expected to help track civil aircraft and ships and avoid tragedies like missing flight MH370.

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

The three spacecraft are equipped with polar region observation cameras as well as automatic identification system (AIS) receivers for information from ships and automatic dependent surveillance-broadcast (ADS-B) receivers for messages sent from civil flights.

The ADS-B system was developed to be installed on civil aircraft and transmit readings of 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 the evening of Sept 28, the STU-2 CubeSats had collected hundreds of thousands of ADS-B messages from more than 12,400 aircraft flying within receiving range.

The paths and traffic flow of civil flights within the satellites' monitoring area may 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, search and rescue in cases like Malaysia Airlines flight MH370," Wu said.

CubeSats may also be used to provide information support for ship operations such as the Chinese icebreaker Xuelong (Snow Dragon) in polar regions.

Wu said the STU-2 mission, the first of its kind by China, is a step in the country's satellite network development for civil aircraft and ship monitoring.

He also called for more international cooperation to expand the network's reach.

Like a Rubik's cube, a CubeSat is a satellite composed of smaller cubic units. Depending on its different uses, a CubeSat may contain two, three or more such units.

Compared with other integral satellites, cube spacecraft are generally smaller, lighter and much more economical in development and production costs.

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