Pioneers 6, 7, 8 and 9
The first satellites designed for long term observation of the Sun from interplanetary space were NASA’s Pioneers 6, 7, 8 and 9, which were launched between 1959 and 1968. These probes orbited the Sun at a distance similar to that of Earth, and made the first detailed measurements of the solar wind and the solar magnetic field.
Helios 1 and 2 probes
In the 1970s the Helios 1 and 2 probes were U.S.– German collaborations that studied the solar wind from an orbit carrying the spacecraft inside Mercury’s orbit at perihelion.
The Skylab space station
The Skylab space station, launched by NASA in 1973, included a solar observatory module called the Apollo Telescope Mount that was operated by astronauts resident on the station.
Skylab made the first time-resolved observations of the solar transition region and of ultraviolet emissions from the solar corona.
Discoveries included the first observations of coronal mass ejections, then called “coronal transients”, and of coronal holes, now known to be intimately associated with the solar wind.
Solar Maximum Mission probes
In 1980, the Solar Maximum Mission probes were launched by NASA. This spacecraft was designed to observe gamma rays, X-rays and UV radiation from solar flares during a time of high solar activity and solar luminosity.
Yohkoh (Sunbeam) satellite
Launched in 1991, Japan’s Yohkoh (Sunbeam) satellite observed solar flares at X-ray wavelengths. Mission data allowed scientists to identify several different types of flares.
Solar and Heliospheric Observatory (SOHO)
One of the most important solar missions to date has been the Solar and Heliospheric Observatory, jointly built by the European Space Agency and NASA and launched in 1995.
It has proven so useful that a follow-on mission, the Solar Dynamics Observatory, was launched in 2010.
Situated at the Lagrangian point between Earth and the Sun (at which the gravitational pull from both is equal), SOHO has provided a constant view of the Sun at many wavelengths since its launch.
Ulysses probe
The Ulysses probe which was jointly built by the European Space Agency and NASA , launched in 1990 to study the Sun’s polar regions. Once Ulysses was in its scheduled orbit, it began observing the solar wind and magnetic field strength at high solar latitudes.
Genesis
A solar wind sample return mission of NASA, Genesis, was designed to allow astronomers to directly measure the composition of solar material.
Solar Terrestrial Relations Observatory (STEREO) mission
Solar Terrestrial Relations Observatory (STEREO) mission of NASA was launched in 2006. Two identical spacecraft were launched into orbits that caused them to (respectively) pull further ahead of and fall gradually behind Earth. This enables stereoscopic imaging of the Sun and solar phenomena, such as coronal mass ejections.
Parker Solar Probe
Parker Solar Probe of NASA was launched in 2018 aboard a Delta IV Heavy rocket and will reach a perihelion of 0.046 AU in 2025, making it the closest-orbiting manmade satellite as the first spacecraft to fly low into the solar corona.
Solar Orbiter mission (SolO)
Solar Orbiter mission (SolO) of ESA (European Space Agency) was launched in 2020 and will reach a minimum perihelion of 0.28 AU, making it the closest satellite with sun-facing cameras.
CubeSat for Solar Particles (CuSP)
CubeSat for Solar Particles (CuSP) of NASA was launched as a rideshare on Artemis 1 on 16 November 2022 to study particles and magnetic fields.
Aditya-L1
Indian Space Research Organisation has launched a 100 kg satellite named Aditya-L1 on 2 September 2023. Its main instrument will be a coronagraph for studying the dynamics of the solar corona.
