JAXA’s SLIM spacecraft landed upside down due to an engine failure. Nut communication has recently resumed after the solar panels received sunlight. (Image Credit: JAXA)
On January 20th, Japan’s Smart Lander for Investigating the Moon (SLIM) spacecraft touched down on the lunar surface. While this marks the nation’s first-ever lunar landing, it’s also the fifth country to achieve such a feat. However, SLIM’s solar cells didn’t work as expected because the spacecraft landed upside down, limiting the craft’s operations to just a few hours, even though it also deployed two rovers. JAXA recently established communication with SLIM and began scientific operations with the Main Board Camera (MBC). It managed to obtain the first light for 10-band observations.
As impressive as it gets, the lander features new precision landing tech that can be used for upcoming moon landing missions. In this case, it helps the spacecraft land on rocky, uneven terrain or in small regions. This capability is crucial as countries try to land at the lunar South Pole. SLIM can touchdown within a 328-foot zone, smaller than other landers that require multiple kilometers.
To capture images of the surface, SLIM uses a vision-based navigation system. Those images are compared with crater pattern data from past missions obtained and developed by JAXA.
Both the rovers are equipped with technology designed to assist with on-the-moon mobility. For example, Lunar Excursion Vehicle 1 has scientific instruments, a camera, and a hopping mechanism to move around. It also has the Lunar Excursion Vehicle 2, a palm-sized, circular rover that splits into two upon landing on the surface so it can roll around.
For the first time, India landed on the moon. (Image Credit: ISRO)
The India Space Research Organization (ISRO) successfully landed its Chandrayaan-3 spacecraft near the moon’s South Pole on August 23rd. According to the space agency, the mission’s objective involved demonstrating end-to-end safe landing and roving on the lunar surface and conducting scientific experiments. A propulsion module transported the solar-powered Pragyan rover and Vikram lander to the South Pole.
Both the rover and the lander performed science experiments in this region. Meanwhile, as part of its Spectro-polarimetry of Habitable Planet Earth (SHAPE) study, the propulsion module collected data on light polarization by gazing at Earth. This could help researchers discover exoplanets that may have identical signatures.
The lander’s ChaSTE (Chandra’s Surface Thermophysical Experiment) measured the lunar topsoil’s thermal temperature and conductivity. This has a temperature probe with ten sensors and a controlled penetration mechanism that can reach a depth of ten centimeters.
On an interesting note, the rover used its Laser-Induced Breakdown Spectroscopy (LIBS) instrument to perform in-situ measurements on the elemental composition for the first time. As a result, it discovered Sulphur on the lunar surface near the south pole, which couldn’t be detected from the orbiters’ instruments.
China’s Chang’E-4 probe captured this image of the far side of the moon on January 3rd, 2019. (Image Credit: China National Space Administration)
On December 14th, 2013, China became the first country and the third overall to soft land on the moon with its Chang’E-3 mission since Soviet Russia did it back in 1976. This mission, as part of CNSA’s Lunar Exploration Program, involved a robotic CE-3 lander and lunar Yutu rover that touched down near Mare Imbrium. Both the rover and the lander used four instruments to perform scientific experiments, observe the Earth, and study the lunar surface’s topography and geology.
China also launched the Chang’E-4 mission, which landed its solar-powered Yutu 2 rover and lander on the far side of the moon in the Von Kármán crater at the South Pole-Aitken Basin on January 3rd, 2019. By studying samples in this region, researchers could get a better understanding of the interior. The Yutu 2 rover used its ground-penetrating radar instrument to study the subsurface structure underneath the wheels.
It also captured data using the panoramic and hazard avoidance cameras and Visible and Near-Infrared Spectrometer (VNIS) instrument, discovering a gel-like substance made of rock. The team relied on a spectral unmixing procedure to break apart the VNIS-measured spectra, helping them figure out how much material was present and its composition. They say the material is dark green and gleaming impact melt breccias. This may indicate glasses are present due to volcano eruption or impact melts.
Meanwhile, the lander, equipped with a Lunar Lander Neutron and Dosimetry (LND) instrument, determined how much radiation would hit an astronaut on the surface --- and that number is approximately 60 microsieverts per hour. As part of the lander’s scientific payload, the LND is partially shielded, giving a good idea of the radiation in a spacesuit.
NASA’s Lunar Reconnaissance Orbiter captured the image of a crater potentially caused by the Luna 25 crash. (Image Credit: NASA’s Goddard Space Flight Center/Arizona State University)
The Russians first-ever soft moon landing occurred on February 3rd, 1966, with its Luna 9 spacecraft. It had cameras equipped on a descent module. When it landed, four petals were deployed for stabilization. Afterward, the cameras captured images of the moon’s surface, transmitting them to Earth. Other noteworthy missions include Luna 16, which also landed on the moon, collected a sample, and returned to Earth.
On August 19th, 2023, Russia attempted a return to the moon after 47 years. But the country's ambitions backfired as the Luna-25 lander crashed into the moon where it would’ve collected samples and performed soil analysis for a year. This happened when they began the maneuver for a landing near the moon's south pole. And Roscosmos officials believe they found the root cause — an accelerometer failed to transmit the correct data to an onboard control unit, which didn't power off the engines. That explains why the engines fired for 127 seconds rather than 84.
Roscosmos said the accelerometer remained off because of the “possible entry into one data array of commands with different priorities for their execution by the device," "This did not allow, when issuing a corrective pulse, to record the moment the required speed was reached and to timely turn off the spacecraft propulsion system, as a result of which its shutdown occurred according to a temporary setting," the post added.
The United States is the first country to land a crewed mission on the moon. (Image Credit: NASA)
The United States soft-landed on the moon in the Flamsteed P crater in the Ocean of Storms on June 2nd, 1966, with its Surveyor 1 spacecraft. This was also the first of seven robotic spacecraft intended to prepare for the Apollo missions by collecting scientific data. Surveyor 1 transmitted engineering data back to Earth to verify it successfully landed on the surface. It then sent the first image, showing the spacecraft, a landing pad, and the soil.
Equipped with a television camera and a filter wheel (red, blue, and green filters), Surveyor 1 captured and sent 10,622 lunar surface images until the June 14th lunar nightfall. It also had a solar panel and batteries, so it wasn’t clear if it would survive the 14-Earth-day lunar night, and it failed to wake up on June 28th. When July 6th arrived, it sent 618 more images after responding to commands. After the July 13th sunset, the battery’s voltage significantly dropped. Controllers maintained contact until January 7th, 1967, when Surveyor 1’s mission ended.
On July 20th, 1969, NASA also became the first country to set foot on the moon with the Apollo 11 mission. The spacecraft carrying all three astronauts, Michael Collins (Command module pilot), Neil Armstrong, and Buzz Aldrin, reached lunar orbit on July 19th. While the lunar module sent Aldrin and Armstrong to the moon's surface in the Sea of Tranquility on July 20th, Collins stayed in the command module orbiting the moon. Armstrong remarked, "That's one small step for man, one giant leap for mankind," after becoming the first astronaut to set foot on the moon. Buzz Aldrin joined in afterward, and both planted the American flag, performed scientific experiments, and gathered samples before returning to Earth.
An additional six trips followed after Apollo 11, and five successfully landed with twelve astronauts walking on the lunar surface in total.
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