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Flotilla of spacecraft planned to provide space weather forecasts

A swarm of spacecraft could be sent into orbit around the sun to provide an early warning system for the huge solar explosions that can interfere with electronic equipment on Earth and even influence our planet's weather.

An image taken on Nasa's Solar Terrestrial Relations Observatory mission Photo: NASA

By Richard Gray, Science Correspondent 9:00PM GMT 12 Feb 2011

Space scientists from the UK are hoping to send up a flotilla of spacecraft to provide round-the-clock three dimensional images of the material thrown out by the sun towards the Earth.

They are hoping to build on the success of a recent Nasa mission, called Solar Terrestrial Relations Observatory (STEREO), which was launched to provide three dimensional images of coronal mass ejections from the sun.

These huge explosions throw millions of tonnes of superheated particles and radiation out into the solar system, which can disrupt radio communications, interfere with electrical equipment, cause power outages and knock out satellites.

They are also thought to bring about changes in the Earth's upper atmosphere that can influence the weather.

UK scientists, who developed the cameras for the Nasa mission, are now in discussions with the European Space Agency, the UK Government and Nasa to develop a new system that will monitor these eruptions.

Professor Richard Harrison, principal investigator on STEREO mission at the Rutherford Appleton Laboratory in the UK who is now among the scientists planning the new forecasting system, said: "We have proved that we can use the information we were getting from STEREO to make predictions.

"We can see these clouds leaving the sun, travelling through space and make predictions about whether they are going to hit the earth and the impact they may have.

"The impacts can be quite significant and more so as we become more dependent on technology that is based in space where the material from these ejections can interfere and knock out satellites altogether.

"We are talking about relatively cheap spacecraft, but the orbit is awkward, so one of the things we are considering is build a lot of little spacecraft, send them out one at a time so that they are drifting around the Earth's orbit of the Sun so that at any time two of these will be able to send back images of the space between the Earth and sun."

Nasa's Solar Terrestrial Relations Observatory mission, or STEREO, was launched in 2006 to provide three dimensional images of the sun by using two probes to take stereoscopic images of the sun and the material it throws out into space.

The STEREO spacecraft have now drifted so that they are on opposite sides of the sun now and they are no longer able to provide those three dimensional images needed to provide predictions of incoming space weather.

Nasa this week released images taken by the two spacecraft that showed for the first time what the sun looks like from two sides at the same time.

Professor Harrison along with Professor Mike Hapgood, head of space environment group at the Rutherford Appleton Laboratory, are now working with scientists and engineers from around the world to develop the next generation of space probes to replace STEREO.

One of the options they are considering is launching a flotilla of spacecraft that will orbit the sun just inside the Earth's own orbit where they could work in pairs to send back three dimensional images as they pass between the Earth and the sun.

This will allow experts to predict the threats from the coronal mass injections from the sun while it could also help terrestrial weather forecasters make more accurate predictions.

Coronal mass ejections are massive bursts of solar wind and radiation that throw millions of tonnes of particles into space from the surface of the sun at speeds of up to a million miles per hour.

Scientists have predicted that the activity of the sun, and so the number of these explosions will increase over the next decade.

There are currently spacecraft that can provide just one hours warning of large coronal mass ejections from the sun, but the new spacecraft could provide twelve to fifteen hours worth of warning for the biggest ejections.

Smaller explosions that throw out material at slower speeds could allow scientists to provide warnings days in advance before they travel the 93 million miles between the sun and the Earth.

Professor Harrison said: "There is a lot of work to be done in deciding how this will work, but there is now a realisation that we need this kind of capability.

"We are trying to get an operational space weather tool up and running so we are talking to government and the space agencies to develop the system."

Professor Mike Lockwood, head of the solar terrestrial physics group at Reading University, said such spacecraft could also provide valuable data for helping to predict weather and other phenomenon, including the aurora, on Earth.

He said another option being considered was a series of disposable spacecraft that could be held in orbit around the Earth before being dispatched at regular intervals.

He said: "This would mean we always have a pair of spacecraft looking at the sun from either side of the Earth to provide a stereo view that can help up predict when ejections are going to hit us and the impact they will have."