Nov 28, 2021 12:00:00

The identity of the mysterious cross carved in the desert was in the American 'Corona Project'

In a corner of the desert in Arizona, USA, there is a concrete cross called 'Casa Grande Calibration Target'. The space review, a space-related news site, explains that the cross was actually a facility used in a military secret project that the United States was conducting during the Cold War.

The Space Review: Candy CORN: analyzing the CORONA concrete crosses myth
https://www.thespacereview.com/article/4094/1

The Casa Grande Calibration Target is located in the desert of Casa Grande, Arizona, and you can also check it on Google Maps.


Looking closer at the Casa Grande Calibration Target, it looks like this.

This cross was prepared for an American military project called the 'Corona Project'. The Corona project was an operation in which the United States photographed communist areas such as the Soviet Union and China from artificial satellites during the Cold War from 1960 to 1972.

The six artificial satellites equipped with high-resolution cameras launched under the Corona project were 'KH-1', 'KH-2', 'KH-3', 'KH-4', 'KH-4A', and 'KH-4B'. The KH-1's camera, launched in 1959, had a ground resolution of 40 feet.

The camera mounted on the KF-1 was a custom-made product equipped with a triple-lens with a focal length of 610 mm and f / 5, and the film was a 70 mm film specially manufactured by Eastman Kodak. Initially, color film was used, but with the technology at that time, the resolution was low when shooting with color film, so basically infrared film was used.

The first photo of the Corona project taken by KH-1 in August 1960 is shown below, and the white line surrounded by a red circle is the runway of Miss Schmitta Airfield in the northern part of the Soviet Union.

With the KH-2 and KH-3 launched in 1963, the cameras have been improved and multiple cameras have been installed. In addition, the KH-4 series was able to shoot at high resolutions of just under 1 foot (about 0.3 meters) by adjusting the altitude.

The following is an illustration depicting KH-4B.

The cross in the desert was the goal for the Corona project satellites to perform calibration. Since the orbit of an artificial satellite may change slightly due to the influence of air resistance, etc., it is necessary for the artificial satellite to accurately grasp the altitude for each mission. The satellite was able to estimate the altitude and the size of the target by taking a 16 mile x 16 mile photo including the Casa Grande calibration target. However, it seems that the Casa Grande Calibration Target was no longer used immediately because the groundwater subsidence caused the groundwater to be assembled and the position of the cross changed.

It seems that there were many calibration facilities other than the Casa Grande Calibration Target, which still remains today. For example, the picture below is an example.

The 'Corona' in the Corona project is just a code name, and its origin is unknown. The existence of the Corona project was, of course, a military secret, and was disguised as part of a space technology development program called 'Discover.' However, when President Jimmy Carter gave a lecture at the Kennedy Space Center on October 1, 1978, he admitted that the U.S. government was using spy satellites, and was declassified by an executive order on February 22, 1995. The photos revealed by the Corona project.