Explorer 17 was a marvel of engineering, designed to study Earth's upper atmosphere with precision. As the first satellite in the Atmosphere Explorer series, it set the standard for subsequent missions. Its technical design was focused on ensuring accurate data collection and maintaining stability in orbit.
Structural Design
The satellite was a pressurized stainless steel sphere, weighing 405 pounds and measuring 35 inches in diameter. This spherical design was chosen
to house the sensitive instruments required for atmospheric study. The pressurization was crucial to protect the instruments from the vacuum of space and ensure accurate readings.
Explorer 17 was stabilized by spinning at about 90 revolutions per minute. This rotation helped maintain the satellite's orientation, allowing its instruments to function correctly. The design also included measures to prevent contamination of the local atmosphere, ensuring that the data collected was as accurate as possible.
Instrumentation
Explorer 17 was equipped with a suite of scientific instruments tailored to its mission objectives. It carried two spectrometers, four vacuum pressure gauges, and two electrostatic probes. These instruments were designed to measure the density, composition, pressure, and temperature of the Earth's atmosphere.
The spectrometers were intended to analyze the composition of atmospheric particles, while the pressure gauges measured the density of these particles. The electrostatic probes were used to assess the temperature and concentration of electrons in the atmosphere. Despite some malfunctions, the instruments provided valuable data that contributed to the understanding of atmospheric science.
Challenges and Achievements
While Explorer 17 was a technical success in many ways, it faced challenges during its mission. One spectrometer malfunctioned, and another operated intermittently, affecting the completeness of the data collected. However, the functioning instruments still provided significant insights into atmospheric conditions.
The satellite's mission ended prematurely when its batteries failed on July 10, 1963, after 98 days in orbit. Despite this, Explorer 17 remained in space until November 24, 1966, when it re-entered the Earth's atmosphere. The data collected during its operational period was instrumental in advancing atmospheric science and laid the groundwork for future missions in the Atmosphere Explorer series.
