Chang'e 4 probe resumes work for 26th lunar day

The lander and rover of the Chang'e-4 probe have resumed work for the 26th lunar day on the far side of the moon. The lander woke up at 3:13 a.m. on Friday (Beijing time), and the rover Yutu-2, or Jade Rabbit-2, woke up at 10:29 a.m. on Thursday, according to the Lunar Exploration and Space Program Center of the China National Space Administration. Landing on the moon on Jan. 3, 2019, the Chang'e-4 probe has survived 736 Earth days on the moon. A lunar day is equal to about 14 days on Earth, and a lunar night is of the same length. The solar-powered probe switches to dormant mode during the lunar night. During the 26th lunar day, Yutu-2 will move northwest toward the basalt area or the impact craters with high reflectivity. Yutu-2 will take panoramic photos, and its infrared imaging spectrometer, neutral atom detector and lunar radar will continue to carry out scientific explorations. Research teams will analyze the detection data and release the scientific results.

China's lunar rover travels over 424 meters on moon's far side

China's lunar rover Yutu-2, or Jade Rabbit-2, has driven 424.455 meters on the far side of the moon to conduct scientific exploration of the virgin territory. Both the lander and the rover of the Chang'e-4 probe have ended their work for the 16th lunar day, and switched to dormant mode for the lunar night due to the lack of solar power, according to the Lunar Exploration and Space Program Center of the China National Space Administration. China's Chang'e-4 probe, launched on Dec. 8, 2018, made the first-ever soft landing on the Von Karman Crater in the South Pole-Aitken Basin on the far side of the moon on Jan. 3, 2019. Yutu-2 has worked much longer than its three-month design life, becoming the longest-working lunar rover on the moon. The rover has helped scientists unveil the secrets buried deep under the surface on the far side of the moon, enriching human's understanding about the history of celestial collision and volcanic activities and shedding new light on the geological evolution on the moon. The scientific tasks of the Chang'e-4 mission include conducting low-frequency radio astronomical observations, surveying the terrain and landforms, detecting the mineral composition and shallow lunar surface structure and measuring neutron radiation and neutral atoms. The Chang'e-4 mission embodies China's hope to combine wisdom in space exploration with four payloads developed by the Netherlands, Germany, Sweden and Saudi Arabia.

China plans to launch its first Mars probe and the Chang'e-5 probe to bring lunar samples back to Earth later this year. CNSA said it was making all-out efforts to carry out the missions amid the coronavirus pandemic.

China unveils Chang'e-4 rover to explore Moon's far side

China's moon lander and rover for the Chang'e-4 lunar probe, which is expected to land on the far side of the moon this year, was unveiled Wednesday. Images displayed at Wednesday's press conference showed the rover was a rectangular box with two foldable solar panels and six wheels. It is 1.5 meters long, 1 meter wide and 1.1 meters high.Wu Weiren, the chief designer of China's lunar probe program, said the Chang'e-4 rover largely kept the shape and conditions of its predecessor, Yutu (Jade Rabbit), China's first lunar rover for the Chang'e-3 lunar probe in 2013. However, it also has adaptable parts and an adjustable payload configuration to deal with the complex terrain on the far side of the moon, the demand of relay communication, and the actual needs of the scientific objectives, according to space scientists. Like Yutu, the rover will be equipped with four scientific payloads, including a panoramic camera, infrared imaging spectrometer and radar measurement devices, to obtain images of moon's surface and detect lunar soil and structure. It will also endure vacuum, intense radiation and extremes of temperature. The moon has a large temperature difference between day and night, which can reach more than 300 degrees Celsius.

Both the lander and rover will carry international payloads for other countries.

The Chang'e-4 lunar probe will land on the Aitken Basin of the lunar south pole region on the far side of the moon, which is a hot spot for scientific and space exploration.

Direct communication with the far side of the moon, however, is not possible, which is one of the many challenges for the Chang'e-4 lunar probe mission.

China launched a relay satellite, named Queqiao, in May, to set up a communication link between the Earth and Chang'e-4 lunar probe.

The global public will have a chance to name the rover, according to State Administration of Science, Technology and Industry for National Defense.

Participants can submit their proposed names for the rover through the internet from Aug. 15 to Sept. 5, and the official name will be announced in October after several selection rounds.

Winners will be rewarded at most 3,000 yuan and invited to watch the lunar probe launch.

The name Yutu was chosen from 200,000 proposals submitted over two months worldwide.

Chinese satellite could link world to Moon's far side: space expert

A satellite with a huge golden umbrella-shaped antenna is in an orbit more than 400,000 km from Earth, waiting for Chang'e-4, which is set to be the first ever probe to land softly on the Moon's far side. The relay satellite for Chang'e-4 will establish a communication link between the Earth and the far side of the Moon, and might serve probes from other countries, contributing to international scientific exploration, said Ye Peijian, an academician of the Chinese Academy of Sciences and one of China's leading space experts. The satellite, named Queqiao, or Magpie Bridge, was launched on May 21 and has entered the Halo orbit around the second Lagrangian (L2) point of the Earth-Moon system, where it can "see" both the Earth and the Moon's far side. The Chang'e-4 probe, including a lander and a rover, is expected to be launched later this year. Its mission to explore the far side of the Moon was proposed by Ye, who has worked in China's lunar exploration program since Chang'e-1 more than 10 years ago. Chang'e-4 follows on from Chang'e-3, which was launched at the end of 2013 and became the first Chinese spacecraft to soft-land on and explore an extraterrestrial object.

After Chang'e-3 accomplished its mission, China's space sector debated Chang'e-4's destination. Some were in favor of landing on the near side of the Moon again, because it's safer.

"I disagreed with that. Why should Chang'e-4 repeat what Chang'e-3 had done? We should not be afraid of failure in scientific exploration. We need innovation," Ye said.

He suggested sending the Chang'e-4 to the Moon's far side. This would be unprecedented and innovative.

He believed the United States and Soviet Union had wanted to do that in their lunar programs, but hadn't because of technological restrictions at the time.

Since the Moon's revolution cycle is the same as its rotation cycle, the same side always faces the Earth, and most of the other side is never seen from Earth. Landing and roving on the far side of the Moon require a relay satellite to transmit signals.

The first ever satellite operating on the Halo orbit around the L2 point, Queqiao used relatively small amounts of fuel during its journey to the planned orbit as it was under precise control. Its designed life is three years, but Ye said it might work for seven or eight years.

That means it could also provide communications for probes from other countries if they intend to explore the Moon's far side in the near future.

"That's the significance of going to the far side of the Moon. China will not only be the first to go there, but will also contribute to world scientific exploration," Ye said.

A reliable long-distance data transmission link is a key technological goal for space experts around the world. Queqiao carries an umbrella-shaped antenna with a diameter of 4.2 meters, the largest communication antenna ever used in deep space exploration.

The antenna was the central difficulty of the relay satellite, and took engineers a long time to develop, according to Ye.

Its name, Queqiao, was selected from more than 100 candidate names in a public naming contest.

In a Chinese folktale, magpies form a bridge to enable Zhi Nyu, a daughter of the Goddess of Heaven, to meet her beloved husband, cowherd Niu Lang, after they were separated by the Milky Way.

"We think the name is easy to understand, and it signifies the establishment of a bridge of communication," Ye said.