Explorer program: Explorer 32 launches.

Explorer 32, also known as Atmosphere Explorer-B (AE-B), was a NASA scientific satellite launched on May 25, 1966, as part of the long-running Explorer program. The mission was designed to study the Earth’s upper atmosphere, particularly the thermosphere and exosphere, where air becomes extremely thin and interacts with solar radiation. The spacecraft was launched from Cape Canaveral aboard a Thor-Delta C1 rocket and became the second mission in the Atmosphere Explorer series. Scientists hoped the satellite would provide direct measurements of atmospheric temperature, density, pressure, and composition at very high altitudes.

The satellite itself was built as a stainless-steel sphere nearly 0.9 meters in diameter and carried a variety of scientific instruments. These included ion and neutral-particle mass spectrometers, electrostatic probes, and pressure gauges used to analyze the thin upper atmosphere. Explorer 32 also introduced several improvements over its predecessor, Explorer 17, including solar cells for longer operational life, a tape recorder for storing scientific data, and magnetic stabilization equipment to help maintain proper orientation in space. These upgrades allowed researchers to collect more continuous and accurate information about the atmosphere than earlier missions had achieved.

Although the launch was mostly successful, the rocket’s second stage burned slightly longer than intended, placing Explorer 32 into a much higher orbit than originally planned. Instead of harming the mission, the unexpected orbit actually gave scientists the opportunity to gather atmospheric data over a wider range of altitudes. Some onboard instruments failed within the first week, but the remaining systems continued to return valuable scientific information for about ten months. Researchers used the data to better understand atmospheric drag, particle density, and how solar activity affects the upper layers of Earth’s atmosphere.

Explorer 32 eventually stopped operating in March 1967 after suffering a depressurization that likely damaged its batteries. Despite the shortened lifespan, the mission was considered highly successful because it provided extensive new information about the near-Earth environment during the early years of the Space Age. The satellite remained in orbit for nearly two decades before finally reentering Earth’s atmosphere on February 22, 1985. Today, Explorer 32 is remembered as an important step in atmospheric science and as part of NASA’s broader effort to understand the conditions surrounding Earth and future space missions.