Labels:text | tool OCR: EXPLORER 1 LAUNCHED ON FEBRUARY 1, 1958, Explorer 1 was the first US satellite to reach Earth Satellite orbit. Being only 16.5 cm (61/2 in) in casing diameter, it contained miniature External instruments to measure atmospheric thermometer temperature, detect radiation levels, and observe meteoroids. Explorer 1 is famous for discovering one of the Van Allen Belts, Flexible communications regions of strong radiation around the antenna Earth. The satellite reached a height of 2,540 km (1,575 miles) above the surface of the Earth. SATELLITE STAYING POWER Explorer 1 transmitted information Rocket for nearly 4 months. Afterward it engine remained in orbit for over 12 years.
