SOLRAD 7A

SOLRAD 7A, also known as Explorer 30, was a United States Navy research satellite launched on November 19, 1965. Its primary mission was to monitor solar radiation, particularly X-rays, to study its effects on radio communications. This was critical for understanding and mitigating disruptions to naval communications caused by solar flares and other solar activity.

The satellite was part of the SOLRAD (SOLar RADiation) program, a series of spacecraft designed to provide continuous observations of the sun's electromagnetic spectrum. SOLRAD 7A carried instruments to measure X-ray and ultraviolet radiation from the sun. The data collected was used to improve forecasting of solar flares and their impact on Earth's ionosphere, allowing for better management of radio communication frequencies and protocols.

SOLRAD 7A was placed in a near-Earth orbit, allowing for regular data transmission to ground stations. The satellite operated successfully for several years, contributing significantly to the understanding of solar-terrestrial interactions. Data obtained from SOLRAD 7A, along with data from other SOLRAD missions, helped refine models of the solar corona and the mechanisms behind solar flares.

The information gathered by SOLRAD 7A proved valuable not only for naval communications but also for general scientific understanding of the Sun and its effects on the Earth's atmosphere. The satellite’s longevity and the quality of its data made it a significant contributor to space weather research during the mid-1960s.