NASA Wind Satellite (1994)

Abstract

The NASA Wind spacecraft, launched in November 1994, provides comprehensive and continuous in situ solar wind measurements while orbiting the Sun–Earth first Lagrange point upstream of Earth. The spacecraft has a full complement of instruments to measure the local magnetic and electric fields and thermal solar wind and high-energy charged particles at unprecedented high time resolutions. After nearly 20 years of operation, the spacecraft and most instruments are fully operational, and Wind is expected to remain in service for many years to come. While Wind provides real-time solar wind measurements for only about 2 h every day – thus it is not considered an operational space weather monitor – the high-quality and continuous Wind observations have been critical in developing current space weather forecasting techniques. In particular, Wind observations led to better understanding of the propagation and evolution of coronal mass ejections quantifying their distortions and deflections. Wind radio science results significantly added to the understanding of the inner heliospheric propagation of interplanetary shocks and high time resolution field and particle measurements revealed the mechanisms of how these shocks and magnetic reconnection can accelerate charged particles to very high and harmful energies. Wind is expected to continue its contribution to the development of future space weather forecasting capabilities as its measurements near two complete 11-year solar cycles allowing the identification of long-term trends.