Probes to the Sun
The sun is the most massive object in our solar system, accounting for 99.8% of the entire mass of the system. Still, we really don't understand it. The various probes are to study and learn more about our life giving star.
- Pioneer 5 (USA) 11 March 1959. Pioneer 5 was
designed to provide the first map of the interplanetary magnetic field. It functioned for
106 days. It is still in solar orbit.
- Pioneer 6 (USA) 16 December 1965. Measured solar
wind and the Sun's magnetic field. Still in solar orbit. Now dormant.
- Pioneer 7 (USA) 17 August 1966. Monitored solar
wind and cosmic rays. Still in solar orbit.
- Pioneer 8 (USA) 13 December 1967. Collected solar
radiation data. Still in solar orbit. Now dormant.
- Pioneer 9 (USA) 8 November 1968. Collected solar
radiation data. Still in solar orbit.
- Pioneer E (USA) 27 August 1969. Destroyed by range
safety due to first stage hydraulics failure.
- Explorer 49 (RAE 2, Radio Astronomy Explorer)
(USA) 10 June 1973. Solar physics mission in lunar orbit 15 June 1973.
- Helios 1 (Helios-A) (USA/Germany-FRG) 10
December 1974. Still in solar orbit. Came within 47 million km of the sun.
- Helios 2 (Helios-B) (USA/Germany-FRG) 16
January 1976. Came within 43 million km of the sun.
- SMM (Solar Maximum Mission) (USA) 14 February
1980. Stayed in Earth orbit, but studied solar flares. Re-entered 2 December 1989.
- Ulysses(International Solar Polar Mission, Solar Polar)
(ESA) 6 October 1990. Went by Jupiter (February 1992) so that it could swing around
and go into a polar solar orbit. First craft to pass over the poles of the sun (south pole
in mid-1994, north pole in mid-1995).
- Solar-A (Yohkoh) (Japan) 30 August 1991.
Japanese mission to study solar flares from Earth orbit.
- SOHO (Solar & Heliospheric Observatory)
(ESA/USA) 12 December 1995. European solar observatory in solar orbit.
- Genesis ( Genesis Solar Wind Sample Return) (USA)
8 August 2001. This robotic probe will park for 2½ years about a million miles
away to collect samples of the solar wind which were then returned to Earth in 2004.
Total material collected was equivalent to about 8 grains of salt.
- Spitzer Space Telescope (SST)
(USA) 25 August 2003. Formally called the Space Infrared Telescope Facility
(SIRTF) before being renamed on 18 December 2003.
- Stereo-A, Stereo-B (USA) 26 October 2006. These are identical
satellites which orbit the sun, Stereo-A(head) of the Earth and Stereo-B(ehind) the Earth.
They will create stereo images of the sun used to predict Coronal Mass Ejections
headed for the Earth.