China is making advanced preparations for the launch of a manned spaceflight, with the recent overhaul of three ships designed to track spacecraft.

This is the strongest indication yet that China is planning to become only the third nation in history to put a human in space. Only the USA and Russia can currently put their own astronauts into space using their own rockets.

China has suggested that it is developing a manned spaceflight ability of its own for many years, but has never confirmed it.

China could put a human in space before 2000

It has sent two astronauts to Russia's cosmonaut training school just outside Moscow. They returned to China without becoming part of a crew to the Russian space station Mir.

Signs that a Chinese manned mission is imminent come from recent reports that shipyards in Shanghai have completed an overhaul of China's space tracking fleet.

The vessels are called Yuanwang 1, 2, 3 and 4 but BBC News Online understands that only three have been overhauled. They are fairly large vessels, weighing 21,000 tonnes fully loaded. They have an extensive array of antennas and tracking dishes.

Chinese television reports that the ships will be assigned to positions in the Pacific, Indian and Atlantic oceans where they will track a new type of spacecraft. It is the first time that the tracking fleet has operated outside the Pacific.

The Chinese already have rocket expertise

The deployment of the fleet mirrors the Soviet deployment of a tracking fleet before manned missions in the past. Analysts say this is a good indication that China is planning a manned spaceflight.

However the forthcoming flight is unlikely to be in a Chinese space shuttle, as has been suggested. It is more likely that it will be in a craft similar to the Soyuz vehicle that the Russians have been using for decades.

A Chinese space shuttle is regarded as too great a leap to make in one step.

China has purchased the Russian Kurs docking system. This would allow two spacecraft to dock in space. This has led to suggestions that an orbital docking could be part of China's plans.

Suggestions that China may be the mystery backer willing to fund the Russian space station Mir have now been discounted.