About the Project: The Solar Probe Plus Spacecraft
The Solar Probe Plus spacecraft is being designed and build by the
Johns Hopkins University Applied Physics Laboratory in Laurel,
Current concept of the Solar Probe Plus spacecraft.
The compact, solar-powered probe will weigh about 1,350 pounds;
preliminary designs include an 8-foot-diameter, 4.5-inch-thick,
carbon-carbon, carbon foam solar shield atop the spacecraft body. The
solar arrays will retract and 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. At its closest passes the spacecraft must survive solar
intensity more than 500 times what spacecraft experience while
orbiting Earth. Check out the spacecraft web page
at JHU/APL for more details.
There are five scientific investigations for
Solar Probe Plus. They are:
Solar Wind Electrons Alphas and Protons (SWEAP)
Investigation. This is our investigation and you can learn about it
by exploring these web pages. The purpose of SWEAP is to scoop up
samples of the atmosphere of the Sun during each of the encounters.
SWEAP measures the detailed properties of electrons, protons, and
helium ions, the main components of the corona and solar wind.
Principal Investigator: Justin C. Kasper,
Smithsonian Astrophysical Observatory, Cambridge, Mass.
The Fields Experiment. FIELDS will make direct measurements of
electric and magnetic fields, radio emissions, and shock waves that
course through the sun's atmospheric plasma. The experiment also
serves as a giant dust detector, registering voltage signatures when
specks of space dust hit the spacecraft's antenna. Principal
Investigator: Stuart Bale,
University of California Space Sciences
Laboratory, Berkeley, Calif.
Integrated Science Investigation of the Sun.
This investigation consists of two instruments that will
monitor electrons, protons and ions that are accelerated to high
energies in the sun's atmosphere. Principal
Investigator: David McComas of the
Southwest Research Institute in San
The Wide-field Imager, a telescope that will make 3-D images of
the sun's corona, or atmosphere. The experiment actually will see the
solar wind and provide 3-D images of clouds and shocks as they
approach and pass the spacecraft. This investigation complements
instruments on the spacecraft providing direct measurements by imaging
the plasma the other instruments sample. Principal Investigator:
Russell Howard, Naval Research Laboratory,
Heliospheric Origins with Solar Probe Plus. Principal Investigator:
Marco Velli, of NASA's
Jet Propulsion Laboratory, Pasadena, Calif., is
the mission's observatory scientist, responsible for serving as a
senior scientist on the science working group. He will provide an
independent assessment of scientific performance and act as a
community advocate for the mission.