When in the U.S.A. it was night, the two twin spacecraft Radiation Belt Storm Probes (RBSP) had a successful lift-off on an Atlas V rocket. After slightly more than an hour the first satellite was deployed and after about twelve minutes the second satellite was deployed as well.

The RBSP mission is part of NASA’s Living With a Star (LWS) program, which aims to study aspects of the Sun-Earth system that directly affect life and society.

The twin RBSP spacecraft have the task to study the van Allen radiation belts, two rings – one internal and one external – of electrically charged particles created by the Earth’s magnetic field around the equator. They’re named after James Van Allen, the physicist who confirmed their existence in the late ’50s thanks to the data of satellite missions Explorer 1 and Explorer 3 after their existence was previously only theorized.

The Sun continuously expels the so-called solar wind, varying but always huge amounts of electrically charged particles that would strike the Earth if it didn’t have a kind of shield that allows only a small amount to pass through creating the van Allen radiation belts.

Research into the van Allen radiation belts have been going on for over fifty years and yet there are still many unanswered questions. This is a problem because the changes in solar activity and in particular magnetic storms affect mainly the outer band. This can cause problems both on the Earth and all the equipment in orbit.

The auroras, northern and southern, are spectacular events generated by the interaction of solar particles with the ionosphere that gives only a small idea of the influence of the Sun on the Earth. In the case of particularly intense solar storms, there may be dangers of damage even to the electricity distribution networks on the Earth and things can get much worse for satellites, which can even be knocked out of service. These peaks of solar activity can also affect people: astronauts are the most vulnerable but even traveling on an airplane you could be affected by electrically charged particles.

In 2013 there will be a peak in solar activity that will lead to strong coronal mass ejections, which are particularly violent solar storms with the consequent risks. These are very practical reasons that led to spending $686 million on the mission of the twin RBSP spacecraft, which are able to withstand the harsh conditions of those areas. They’re equipped with various instruments to monitor changes in the Van Allen radiation belts.

The two RBSP spacecraft will work in almost identical orbits that will travel at slightly different speeds. In this way, it will be possible to have measures of the same area of the van Allen belts at different times and compare them.

The mission of the RBSP spacecraft is scheduled to last for two years. We hope that it will revolutionize our knowledge of the van Allen belts and above all, it will enable us to find ways to protect ourselves from the peaks of solar activity.