Luna 25 (Russian: Луна-25), also known as the Luna-Glob lander, was a failed Russian lunar lander mission operated by Roscosmos. It was the first lunar mission undertaken by Russia since the Soviet-era Luna 24 in 1976, and was intended to be the first spacecraft ever to land near the lunar south pole. The spacecraft was manufactured by NPO Lavochkin and carried 30 kg (66 lb) of scientific instruments, including instruments for analyzing lunar regolith and measuring plasma in the exosphere.
Luna 25 lifted off on August 10, 2023, at 23:10 UTC, atop a Soyuz-2.1b rocket with a Fregat upper stage from the Vostochny Cosmodrome in Russia's Amur Region. The spacecraft entered lunar orbit on August 16, 2023, with a scheduled landing date of August 21 near the crater Boguslawsky. On August 19, 2023, a failed orbital maneuver caused the lander to follow a trajectory that intersected with the lunar surface rather than the planned elliptical orbit. The spacecraft crashed into the inner rim of Pontécoulant G crater at 11:57 UTC, approximately 400 kilometers short of its intended landing site. The impact site was later identified by NASA's Lunar Reconnaissance Orbiter.
Originally named the Luna-Glob lander, the mission was renamed Luna 25 to emphasize continuity with the Soviet Union's historic Luna programme, though it remained part of the modern Luna-Glob lunar exploration program. At least 12.5 billion rubles (over US$130 million) had been spent on the project prior to its failure.
The previous lunar lander in the series was a Soviet craft, Luna 24, launched in 1976. Nascent plans for what became Luna 25 began in the late 1990s, with the evaluation of two spacecraft designs having taken place by 1998. Attempts to revive and complete the project continued throughout the 2000s and were punctuated by an aborted attempt at international cooperation via a merger with JAXA's now-cancelled Lunar-A orbiter, and pressure from another attempted cooperative lunar mission with Indian Space Research Organisation (ISRO) (which continued without Russia's involvement).
Initial mission plans called for a lander and orbiter, with the latter also deploying impact penetrators. In its final form, Luna 25 was a lander only, with a primary mission of testing the landing technology. The mission carried 30 kg (66 lb) of scientific instruments, including a robotic arm for soil samples and possible drilling hardware.
Delays in the 2010s came first from the significant rework and delay brought on by the failure of Phobos-Grunt in 2011. At this point the modern Luna 25 design was developed. Later work on the lander was slowed by resource pressures being placed upon spacecraft developer NPO Lavochkin, such as the weather satellite Elektro-L No.2 and the Spektr-RG observatory, as well the landing platform Russia was contributing to ExoMars 2020.
By 2017, the propulsion system for the spacecraft was in assembly.
The intended landing site was located at 69.545°S 43.544°E / -69.545; 43.544 (Luna 25 primary landing site) (north of the crater Boguslawsky), with two backup locations at 68.773°S 21.210°E / -68.773; 21.210 (Luna 25 alternate landing site) (southwest of the Manzini crater) and 68.648°S 11.553°E / -68.648; 11.553 (Luna 25 alternate landing site) (south of Pentland A crater).
The planned mission duration of the lander on the surface of the Moon was to be at least one Earth year.
At least 12.5 billion roubles (over US$130 million) had been spent on the project.
The lander featured a 30 kg (66 lb) payload comprising eight Russian science instruments:
ADRON-LR, active neutron and gamma-ray analysis of regolith
ARIES-L, measurement of plasma in the exosphere
LASMA-LR, laser mass-spectrometer
LIS-TV-RPM, infrared spectrometry of minerals and imaging
PmL, measurement of dust and micro-meteorites
THERMO-L, measurement of the thermal properties of regolith
STS-L, panoramic and local imaging