Links to the many spacecraft and institutions who study the Sun and geospace...
NASA Programs
Sun-Earth Connections Science Theme
http://sec.gsfc.nasa.gov/
International Solar-Terrestrial Physics
http://istp.gsfc.nasa.gov/
Solar-Terrestrial Probes
http://stp.gsfc.nasa.gov/
Living with a Star
http://sec.gsfc.nasa.gov/lws.htm
Other Institutions
The NOAA Space Environment Center
http://www.sec.noaa.gov/
The U.S. Air Force Battlespace Environment Division
http://www-vsb.plh.af.mil/
National Solar Observatory
http://www.nso.noao.edu/index.html
High Altitude Observatory
http://www.hao.ucar.edu/
Current Spacecraft (NASA, ESA, Japan, Russia)
SOHO
http://sohowww.nascom.nasa.gov/
TRACE
http://vestige.lmsal.com/TRACE/
Yohkoh
http://www.lmsal.com/SXT/
HESSI
http://hessi.ssl.berkeley.edu/
ACE
http://helios.gsfc.nasa.gov/ace/ace.html
Wind
http://www-spof.gsfc.nasa.gov/istp/wind/
Ulysses
http://ulysses.jpl.nasa.gov/
Polar
http://www-spof.gsfc.nasa.gov/istp/polar/
Cluster II
http://sci.esa.int/cluster
Genesis
http://www.genesismission.org/educate/index.html
INTERBALL
http://www.iki.rssi.ru/interball.html
IMAGE
http://pluto.space.swri.edu/IMAGE/
SAMPEX
http://sunland.gsfc.nasa.gov/smex/sampex/index.html
Geotail
http://www-spof.gsfc.nasa.gov/istp/geotail/
TIMED
http://www.timed.jhuapl.edu/
FAST
http://plasma2.ssl.berkeley.edu/fast/welcome2.html
IMP-8
http://nssdc.gsfc.nasa.gov/space/imp-8.html
Voyager
http://vraptor.jpl.nasa.gov/voyager/voyager.html
SNOE
http://lasp.colorado.edu/snoe/
