“China appears to have pulled off not only the first satellite-to-satellite refuelling in geosynchronous orbit, but also the ‘largest single manoeuvre’ ever seen in that orbit, according to a former US Space Command official.

The two spacecraft – the Shijian-21 and Shijian-25 – have been docked some 36,000km (22,370 miles) above Earth since early July. Their mysterious mission was widely believed to involve the Shijian-25 supplying the Shijian-21 with propellant.

Last month, they executed what Lieutenant General John Shaw called ‘the largest single manoeuvre ever conducted in geosynchronous orbit’, shifting their track with a velocity change of more than 330 metres (1,083 feet) per second.”

From South China Morning Post.