European meteorologists have had to wait 16 years, so one more day of anticipation should be manageable.

The European Space Agency's (ESA) launch of a Vega rocket of the Aeolus satellite, which will map wind patterns by laser, has been postponed by at least a day.

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Aeolus will measure wind patterns using laser (Photo: ESA)

The reason why the launch cannot go ahead as scheduled on Tuesday (21 August) was ironic: weather conditions. More specifically: winds.

"From a technology point of view, the satellite is all fine, the rocket is all fine. It's really the wind," said Josef Aschbacher, director of earth observation at ESA.

He spoke to journalists on Monday, en route from Paris to Cayenne in French Guyana.

During the flight, it was not yet clear whether Tuesday's launch could go ahead.

"Before I left, I got information that the wind is not good for tomorrow," said Aschbacher.

"Strangely enough the wind may stop us launching the wind mission," he joked.

He was unperturbed by the possible delay, however.

"If we don't launch tomorrow, we'll try again in 24 hours. We can try every day until we get a good weather forecast," he said.

On the scale of time between the decision to build Aeolus and its launch, the delay was insignificant.

Work started in 2002, with a scheduled launch five years later.

Aeolus will observe wind patterns from space using a laser instrument.

To produce such a laser that would work in a vacuum proved to be quite a challenge.

"We have been testing it on the ground, where it works. But in vacuum, we encountered some problems, which we could not overcome for a long time," said Aschbacher.

"Aeolus was meant to be launched much earlier, but because of these technological hurdles we encountered, the development time took much longer," he said.

"The original launch date was 2007. Now it is 2018, so 11 years later, which also shows how difficult it was."

According to Aschbacher, meteorologists are eagerly awaiting for wind profiles from space.

"Wind measurement is the biggest observation gap in meteorology in order to improve weather forecasts," he noted.

Aschbacher went on to say that some storms that previously had not been forecast, could have been foreseen if Aeolus had been feeding information to weather prediction models.

He said the instrument will help predict extreme events such as storms and hurricanes better - and could therefore save lives.

"If you have a better prediction of storms, yes, it will eventually result in saving lives and reducing damage," he noted.

The €480m project is set to be a showcase of European innovation.

"Some other countries have tried - NASA for example - but not succeeded. This would be the first time a UV laser would fly in space," said Aschbacher, referring to the US space agency.

Temporary mission

The Aeolus mission has a planned period of only 3.5 years, to test if the system works.

"[It is] a proof of concept, I really want to underline that," he said.

If the test run is successful, a subsequent decision would have to be made about new satellites to be put in orbit permanently.

The main user of Aeolus will be Europe's meteorological organisations, although anyone could in theory see the measurements.

"Our data are free and open. But you can really only use the data if you can assimilate them in a weather prediction model in order to really make use of them," said Aschbacher.

Aeolus data will not only contribute to daily weather forecasts, but can also be used by climate change researchers.

The launch, carried out by private company Arianespace, is now scheduled for Wednesday, 23:20:09 Brussels time.