One of the first of these was the IMP-8 (Interplanetary Monitoring Platform)[54] It orbited the Earth at 35 Earth Radii and observed the solar wind for two-thirds of its 12-day orbits from 1973 to 2006. Since the solar wind carries disturbances that affect the magnetosphere and ionosphere, IMP-8 demonstrated the utility of continuous solar wind monitoring. IMP-8 was followed by ISEE-3, which was placed near the L1 Sun-Earth Lagrangian point, 235 Earth radii above the surface (about 1.5 million km, or 924,000 miles) and continuously monitored the solar wind from 1978 to 1982.