The launch date for Tiangong 1, China's first space laboratory, has been the subject of much confusion in recent months. It seems that a launch is not too far away, and could appear within a week.

It needs to happen soon. Just as there have been reasons for delaying the launch of Tiangong, there are reasons why it cannot be delayed too much longer.

Rumours of a Tiangong launch by the end of August were challenged by the launch failure of a Long March 2C rocket in the same month. Soon afterwards, a former senior official with China's human spaceflight program suggested that the failure would have no influence over the upcoming Tiangong flight.

This writer didn't believe it, and evidence in support of this was soon released. Chinese officials had sensibly announced that there would be a brief delay in the launch, to allow some time for checking the cause of the failure.

There was obvious potential for a common link in the chain of failure between the failed rocket and the rocket to be used for Tiangong. That needed to be considered, but it would also seem that it did not take too long to rule it out.

This suggests that Chinese officials have a fairly good idea of what went wrong with the Long March 2C launch, and can state that there's no connection to any potential faults with the Long March 2F/G rocket, which is expected to loft Tiangong 1.

If all goes well, we can expect a launch before the middle of September, according to People's Daily.

Fair enough. There seems to be a sensible balance between caution and the need for progress. But it's been a spooky time for rocket people.

In recent weeks, we have witnessed failures in the aforementioned Long March rocket, a Russian Proton rocket and a Russian Soyuz rocket carrying a Progress cargo spacecraft to the International Space Station. Now there are delays for the next Soyuz crew launch to the ISS, and even talk of the possibility of leaving the Station crewless for a while! Trouble seems to come in clusters.

Tiangong would thus seem ready to fly on its long-delayed mission. Ideally, the laboratory would have been in the sky a year ago. We are all growing frustrated with the delays.

Apart from the emotion, there are also some practical reasons to light this candle. Launch systems, infrastructure and personnel cannot stay "ready" for too long. Eventually things start to wear out. This applies to the Tiangong spacecraft as much as the Long March rocket. If things have been certified as flight worthy, it makes sense to use them while they remain this way.

There's also the question of weather. We need fairly good conditions at the launch site, ground tracking stations, and on the high seas, where China will deploy its fleet of tracking vessels. Waiting too long threatens to disrupt conditions with cold blizzards and choppy seas.

There's also a political question. October is an important month of celebration within China, as the nation celebrates its birthday. An orbiting space laboratory would be a nice way to commemorate this, and boost public morale in uncertain times.

The waiting is almost over. We hope things go well. Otherwise, we could be waiting a lot longer for the launch of Tiangong 1.

Dr Morris Jones is an Australian space analyst and writer. Email morrisjonesNOSPAMhotmail.com. Replace NOSPAM with @ to send email. Dr Jones will answer media inquiries.