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Trajectories of Selected Spacecraft, Planets, and Comets
NSSDC provides trajectory data (position vs. time) for certain spacecraft making in situ observations of the particles, plasmas and fields environment of the Earth's magnetosphere and of the "near-Earth" and deep-space solar wind.
Recall that the magnetosphere is the region of space controlled by the Earth's magnetic field, being approximately hemispherical on the day side of the Earth with a variable radius about 10-12 times the Earth's radius and being approximately cylindrical on the night side extending 200+ Earth radii in the anti-sun direction. The diameter of this nightside magnetotail gradually increases with distance from the Earth.
Recall that spacecraft measuring the near-Earth solar wind are in geocentric orbits which are partly outside the magnetosphere or are in "libration point" orbits about 200 Earth radii sunward of the Earth. Finally recall that spacecraft measuring the deep space solar wind or its cosmic rays are many times the distance from the sun that the Earth is. The Earth is at 1 Astronomical Unit (AU; about 93 million miles) from the sun. The furthest spacecraft is the 1977-launched Voyager 1, about 74 AU from the sun in April, 1999.
NSSDC provides magnetospheric spacecraft trajectories through an interface called SSCWeb. NSSDC provides solar wind (heliospheric) trajectories through a family of WWW pages generically called heliospheric ephemerides pages. The latter pages also provide trajectory information for selected planets and for selected comets.
Orbit parameters and high level characterizations of orbits for all or most spacecraft are contained in the spacecraft-specific records of the NSSDC Master Catalog.