Chang’e-4 powers down to farside landing.
Credit: CCTV/Screengrab/Inside Outer Space

 

If all remains on schedule, China’s Chang’e-4 is slated to attempt the first controlled farside landing in history.

The target remains the Von Kármán crater, within the South Pole‐Aitken (SPA) basin.

Chang’e-4 touchdown on Moon’s farside.
Credit: CCTV/Screengrab/Inside Outer Space

 

The scientific instruments of China’s farside spacecraft, mounted on a lander and a rover, will analyze both surface and subsurface of this region.

Landing ahead

One of those experiments mounted on the lander is a German lunar neutron and radiation dose detector to explore the farside surface environment.

Germany’s scientific payload is a Lunar Lander Neutron and Dosimetry instrument, developed by Kiel University.
Credit:
Kiel project manager. Jia Yu

“Yes, indeed, we are anxious to get the first data after landing on the farside of the Moon tomorrow at 08:20 CET,” says Robert F. Wimmer-Schweingruber of the University of Kiel. “It’ll be exciting to see the first data and check out instrument health. The plan is still to land in the Von Kármán crater,” he told Inside Outer Space in an early morning January 2nd communique.

No official word on the landing attempt time from Chinese space authorities.

Other international joint collaboration payloads within the Chang’e-4 explorer mission includes Sweden’s Advanced Small Analyzer for Neutrals (ASAN) installed on the rover and the Netherlands-China Low-Frequency Explorer (NCLE) installed on the relay satellite.

Candidate landing region of China’s Chang’e-4 lander within Von Kármán crater in SPA basin.
Credit: Jun Huang, et al.

Crater facts

The Von Kármán crater is approximately 115 miles (186 kilometers) in diameter, lying in the northwestern SPA basin. The topography of the landing region is generally flat.

The SPA basin is the largest and oldest impact basin of the Moon.

Von Karman Crater as viewed by the Lunar Reconnaissance Orbiter Camera, or LROC,
Credit: NASA/GSFC/Arizona State University

Although the terrain is low, this region is not filled with mare basalts as other Moon basins suggesting its special thermal history and unique evolution features.

The materials in the region are likely to be of great significance to reveal the compositions of the crust and even the mantle of the Moon. Lunar exploration data show that SPA basin possesses unique geochemical characteristics.

Relay satellite

Prior to the Chang’e-4 mission, a detailed 3-D geological analysis of the nature and history of Von Kármán crater was done; the region contains farside mare basalts affected by linear features and ejecta material from a wide range of surrounding craters; and a new geological analysis provided a framework for the Chang’e-4 mission to carry out on-the-spot exploration.

Chang’e-5 mission rocket’s lunar samples into Moon orbit.
Credit: CCTV/Screengrab/Inside Outer Space

Already in place and ready for action for the upcoming mission is the Chinese relay satellite Queqiao. Queqiao was successfully launched last May on a Long March 4C from the Xichang Satellite Launch Center. That relay spacecraft successfully reached an Earth-Moon L2 halo orbit to support communications between Earth and the Moon’s farside…and future farside missions.

Exploration outing

Since both the lander and the rover were designed as a backup for the December 2013 Chang’e-3 mission – a lander carrying the Yutu rover — some of the science payloads on Chang’e-4 are similar, such as a landing camera, a terrain camera, a panorama camera on the lander and a visible/near infrared imaging spectrometer, along with two ground penetrating radars able to reveal the subsurface structure of the landing area.

China’s next lunar probe, Chang’e-5, is designed to bring select samples from the Moon back to Earth. It builds upon a progression of Chinese Moon explorers: Chang’e-1 and Chang’e-2 orbiters in 2007 and 2010, respectively, and the Chang’e-3 lunar lander/rover mission in December 2013.

An informative paper — “Geological Characteristics of Von Kármán Crater, Northwestern South Pole-Aitken Basin: Chang’E-4 Landing Site Region” – has been published in the American Geophysical Union’s Journal of Geophysical Research: Planets.

It can be found here:

http://www.planetary.brown.edu/pdfs/5294.pdf

One Response to “China’s Chang’e-4 Moon Lander: What’s Up With Going Down?”

  • Ron says:

    Good Morning Leonard,

    Just need to wait for the sun to rise at the landing site.

    Many of us hope that a successful Chinese landing will be a “Wake Up Call” for renewed U.S. Moon exploration missions – it has been over 46 years since we last visited our neighbor!

    Ron

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