Washington, May 2 : The John Hopkins University Applied Physics Laboratory (APL) is planning to send a spacecraft closer to the Sun than any probe has ever gone before in 2015, which could help to reveal a wealth of information about the star and the solar wind that influences everything in our solar system.
Experts in the US and abroad have grappled with this mission concept for more than 30 years, running into seemingly insurmountable technology and budgetary limitations.
But in February, an APL-led team completed a Solar Probe engineering and mission design study at NASA's request, detailing just how the robotic mission could be accomplished.
The study team used an APL-led 2005 study as its baseline, but then significantly altered the concept to meet challenging cost and technical conditions provided by NASA.
It will study the streams of charged particles the sun hurls into space from a vantage point within the sun's corona - its outer atmosphere - where the processes that heat the corona and produce solar wind occur.
At closest approach, Solar Probe would zip past the sun at 125 miles per second, protected by a carbon-composite heat shield that must withstand up to 2,600 degrees Fahrenheit and survive blasts of radiation and energized dust at levels not experienced by any previous spacecraft.
APL will design and build the spacecraft, on a schedule to launch in 2015.
The compact, solar-powered probe would weigh about 1,000 pounds; preliminary designs include a 9-foot-diameter, 6-inch-thick, carbon-foam-filled solar shield atop the spacecraft body.
Two sets of solar arrays would retract or extend as the spacecraft swings toward or away from the sun during several loops around the inner solar system, making sure the panels stay at proper temperatures and power levels.
Solar Probe will employ a combination of in-place and remote measurements to achieve the mission's primary scientific goals: determine the structure and dynamics of the magnetic fields at the sources of solar wind; trace the flow of energy that heats the corona and accelerates the solar wind; determine what mechanisms accelerate and transport energetic particles; and explore dusty plasma near the sun and its influence on solar wind and energetic particle formation.
The Solar Probe mission will use seven Venus flybys over nearly seven years to gradually shrink its orbit around the sun, coming as close as 4.1 million miles (6.6 million kilometers) to the sun, well within the orbit of Mercury and about eight times closer than any spacecraft has come before.
Story first published: Friday, May 2, 2008, 13:38 [IST]