Washington, April 20 : The designing aspect of NASA's twin spacecraft has begin, which will be sent into the radiation belts to provide unprecedented insight into the physical dynamics of near-Earth space.
Known as the Radiation Belt Storm Probes Mission (RBSP), the two identical probes are being designed by researchers and engineers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Maryland, and a number of other institutions.
APL will build and operate the twin probes, which are scheduled for a 2011 launch and a primary mission of two years.
The area of space known as the radiation belts are two donut-shaped regions encircling Earth, where high-energy particles are trapped by the planet's magnetic field.
Most Earth-orbiting spacecraft pass through the belts, and when the energy and density of the particles increases, it becomes more likely that an astronaut or spacecraft will be affected.
The radiation belts also affect satellites and even ground-based technologies.
High-energy particles striking human tissue can alter the chemical bonds within cells, damaging or destroying them. When a particle strikes a satellite, it can overwhelm sensors, damage solar cells and degrade wiring and other sensitive electronics.
Large changes in the magnetic field near Earth's surface associated with space weather storms can induce currents that flow through-and affect the operation of-railroad systems, power transmission lines and pipelines.
The RBSP mission seeks to resolve decades-old scientific mysteries of how these particles become energized to such high levels, and how the radiation belts vary so dramatically with changing conditions on the sun.
According to Barry Mauk, project scientist for RBSP, "The radiation belts were a scientific curiosity when they were discovered 50 years ago by James Van Allen, who was one of the founding members of APL."
"But the belts are becoming very important because we have people and machines operating in them. That region of space is now part of our technology infrastructure," he added.
"If we can understand the radiation belt environment and its variability, we can apply this knowledge to improve our spacecraft operation and system design, mission planning and astronaut safety," said Mauk.
The probes will measure the particles, waves, and magnetic and electric fields that fill near-Earth space to improve our understanding of how the sun's changing energy flow affects them.
These observations will help researchers understand how charged particles are energized at Earth, but also the processes that create particle radiation throughout the universe in stars, interplanetary space and distant nebulae.
The observations will also help researchers develop various models for the radiation belts that will be used by engineers to design radiation-hardened spacecraft, and by forecasters to predict space weather phenomena and alert astronauts and spacecraft operators to potential hazards.