Roscosmos announces that the motor drive for orbital adjustment failed to operate in time
Today, August 19, 2023, according to the flight program, at 14:10 (Moscow time) / 11:10 UTC an impulse was commanded to maneuver the Luna-25 automatic station to the pre-landing orbit on the lunar surface. During the operation, an “abnormal situation” (euphemism for 'breakdown') occurred on board the automatic station, which did not allow the maneuver to be carried out with the specified parameters. According to Roskosmos, the management team is analyzing the situation. If controllers be able to correct the problem, it is possible that the landing site will be changed to the alternative target – Manzini Crater and landing date can be moved to August 23, 2023. The spacecraft is in a 91.4 km x 112.6 km orbit around the Moon with an inclination of 82.087 degrees towards the lunar equator and an upward angle of 270.53 degrees of longitude. The mass of the spacecraft after reaching lunar orbit was 1750 kg.
Alexander Ivanov, First Deputy General Director for the development of the orbital constellation and promising projects of Roskosmos, personally came to NPO. Lavochkin and holds a meeting on the situation with the apparatus "Luna-25". So far, it has not been possible to establish a connection with the device. His condition is unknown. If the reports that the apparatus gave out an impulse to decelerate one and a half times more than the norm are true, then the apparatus is already at rest in the Sea of Tranquility on the surface of the Moon. So to speak, ahead of schedule carried out a hard landing."
Yesterday, the Russian space agency released the first results of the work of the Luna-25 scientific instruments in lunar orbit. The spacecraft should try to land on the surface between the 21st and 23rd. Meanwhile, several activations of scientific equipment were carried out. Analyzing their data, the following results were
▪️ In the energy spectrum of gamma rays, the ADRON-LR neutron and gamma spectrometer recorded the most intense lines of chemical elements in the lunar soil.
▪️ For the first time in orbit, the ARIES-L ion energy mass analyzer was turned on, designed to study the ionic near-surface exosphere in the subpolar region of the Moon. The data allowed choosing the ideal mode of operation for the device on the lunar surface to measure the energy spectrum of particles in the energy range from 10 eV to 3000 eV.
▪️ The PML device, designed to detect microparticles levitating close to the surface and determine the parameters of the surrounding plasma, recorded the impact of a micrometeorite. Most likely, this micrometeorite belongs to the Perseid meteor shower, which the spacecraft crossed during its flight to the Moon.
▪️ According to the results of processing two frames of images of the Moon, taken on August 17th by the system's landing cameras STS-L, experts from IKI RAS and MIIGAiK realized a digital elevation model. This technology will allow the future to significantly improve the accuracy of knowledge of the spacecraft's orbit.
The photos show the Zeeman Crater. In the list of the twenty deepest craters in the southern lunar hemisphere, he is in third place. It has an unusual size ratio, with a diameter of about 190 km and a depth of about 8 km. Its formation is associated with a very strong impact, which is possible if the speed of the impactor is too high or its substance is too dense. Detailed photographs show that the bottom of the crater is dotted with smaller ones. This happens if part of the substance ejected on impact falls and creates several small "holes". Such formations are very interesting from the point of view of lunar geology.
Indian Lunar station works normally
The Indian space agency ISRO announced today that the lander module maintains a stable orbit of 113 km x 157 km around the Moon, and that a second ignition of the braking engines is planned for tomorrow the 20th, to adjust the trajectory of the spacecraft aiming at the landing on the 23rd.
The landing module of the automatic lunar station separated from the orbital module on the 17th, in a successful maneuver that paves the way for the landing at the south pole of the Moon on the next 23rd, when the probe's Vikram landing module will land at coordinates 69.367621 S, 32.348126 E.
The Indian lunar mission was launched on July 14. If successful, India will become the fourth country to land on the Moon (after the USSR, USA, and China). The Chandrayaan-3 station is the third lunar exploration vehicle launched by India.