Luna 23 was to drill 2.5 meters below the lunar surface (compared to the 0.3-m depth of the cores sampled by Luna 16 and 20) and return a sample of the soil to Earth.
The drilling apparatus was damaged during landing, preventing execution of the sample-return mission. Little or no science was done with the stationary lander.
Oct. 28, 1974 | 14:30:32 UT: Launch
Nov. 2, 1974: Lunar Orbit Insertion
Nov. 6, 1974: Lunar Landing
Nov. 9, 1974: End of Mission
Luna 23 was the first modified lunar sample-return spacecraft, designed to return a deep-core sample of the Moon's surface (hence the change in index from Ye-8-5 to Ye-8-5M). While Luna 16 and 20 had returned samples from a depth of about 1 foot (0.3 meters), the new spacecraft was designed to dig to about 8 feet (2.5 meters).
After a midcourse correction on Oct. 31, Luna 23 entered orbit around the Moon on Nov. 2, 1974. Parameters were 65 x 58 miles (104 x 94 kilometers) at 138 degrees inclination. Following several more changes to the orbit, the spacecraft descended to the lunar surface on Nov. 6 and landed in the southernmost portion of Mare Crisium. Landing coordinates were 13 degrees north latitude and 62 degrees east longitude.
During landing in unfavorable terrain, the lander's drilling device was evidently damaged, preventing it from fulfilling its primary mission: the return of lunar soil to Earth. Scientists devised a makeshift plan to conduct a limited science exploration program with the stationary lander. Controllers maintained contact with the spacecraft until Nov. 9, 1974.
Launch Vehicle: Proton booster plus upper stage and escape stages, 8K82K + Blok D (Proton-K no. 285-01)
Spacecraft Mass: About 13,000 pounds (5,800) kilograms
Stereo imaging system
Improved drill for sample collection
- Credit: NASA