Rangers

 In the 1960s, NASA conducted a series of unmanned lunar missions known as the Ranger program. The primary objective of these missions was to obtain detailed images of the lunar surface and collect scientific data to aid in the planning of future manned missions under the Apollo program. Below, some of the Ranger missions and their context are described:

• Ranger 1 and Ranger 2: These were the initial missions of the program and were launched in 1961. Both missions experienced failures and failed to transmit images of the Moon.
• Ranger 3: Launched in January 1962, Ranger 3 was designed to impact the Moon and transmit images as it approached. However, a propulsion system failure caused the probe to pass by the Moon and be lost in deep space.
• Ranger 4: Launched in April 1962, Ranger 4 was the first successful impact of a Ranger probe on the Moon. Although it couldn't transmit images due to an antenna malfunction, it achieved its primary objective by providing data on lunar dust density.
• Ranger 6, 7, 8, and 9: These missions successfully transmitted high-resolution images of the lunar surface before impact. Ranger 7, launched in July 1964, was particularly successful, transmitting over 4,000 images before crashing into the Moon.

These Ranger missions were crucial for Apollo mission planning, offering vital information about lunar surface conditions and ensuring safe landing sites for future manned missions. It's worth noting that not all Ranger missions were successful, but those that were played a fundamental role in the success of the Apollo program and the historic human landing on the Moon in 1969.