Japan on Tuesday successfully launched the fourth and final satellite that makes up its terrestrial positioning network system, which will improve the current GPS services and help create a better communications system during a disaster.The Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries launched a Japanese H-IIA rocket with the Michibiki-4 communications satellite from the space centre on Tanegashima Island, Kagoshima prefecture, at 7.01 a.m., reports Efe news. The launch and flight of the rocket "proceeded as planned," as well as the satellite separation, which was "confirmed 28 minutes and 21 seconds after the launch time", JAXA said in a statement. This is the second system that Japan launches as part of its Quasi-Zenith Satellite Systems, which operate at an altitude of between 33,000 and 39,000 km above the earth and whose function is to correct the global navigation satellite system signals for complementary use of the global positioning system (GPS). The first Michibiki, meaning "guide" or "guidance" in Japanese, was launched in September 2010, allowing smartphone users and portable navigation devices in vehicles to receive more accuracy on maps. The GPS, owned by the US, has a margin of error of about 10 metres in global positioning; the coordination between the GPS and Michibiki will reduce the margin to between 1 metre and about 6 cm. The Japanese government plans to use these satellites to establish communications during a malfunction of traditional networks due to a natural disaster. Japan plans to launch three satellites between 2018 and 2023 that will complement the positioning network and establish the emergency communications system.