Yutu Rover
On the 2nd of December 2013 China launched the Chang'e-3 mission to the moon.[1] It included the Yutu rover, also known as Jade-Rabbit. Yutu was the name of a jade rabbit pet of a mythical Chinese moon goddess.
Soft landing on the moon was achieved on the fourteenth of December 2013.[2] Yutu rolled out onto the lunar surface and was planned to operate for three months. It had cameras on a mast, ground-penetrating radar, an alpha particle x-ray spectrometer and a visible/infrared spectrometer. The lander and rover took pictures of each other and used their scientific instruments as planned.[3]
Yutu had a mechanical control problem before the 25th of January 2014. It was no longer able to move and some instrument operations failed.[4]
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Details Possibly Related to malfunctions
The Chinese had tested their technology in a simulated lunar environment for forty days before the mission launch.[5] Still, malfunctions occurred on the moon which mission operations was unable to specifically identify. A candidate cause for malfunctions would be dust stirred into electrostatic levitation along the terminator as the lunar day began and ended. Such dust grains can shoot higher than the height of the rover and lander and can cause problems with complicated mechanical devices, especially telescoping mechanical linkage. Placing some of a rover's joints in gas tight sleeves with accordion type folds to protect them from dust might help while limiting the range of motion of devices and using up limited mass and volume budgets. Another possible remedy, to be used later when more equipment is in place, is to build a shelter from dust that robots can retreat into to avoid the dusk and dawn dust storms if not to avoid the night also. If dust is part of the problem, it might help to explain why the simulated lunar environment did not lead mission developers to anticipate the problem. Electrostatically levitated dust is difficult to simulate. The Geminid meteor shower likely stirred up dust on the surface of the moon hours before Chang'e 3 landed.[6] Taking into account meteor shower times and avoiding them for landing on the moon is just one more complication to the task of exploring the moon.
There was considerable attention to documenting mission performance in a step by step way but now there is more information to show mission developers what sort of self-diagnostics are most likely to be helpful on future missions.
The Significance of Rover Exploration
If there is ever to be industrial development on Luna, the location and condition of the various mineral resources must be learned in detail. Yutu was designed to make progress on this front. The hazards to machines working on Luna must also be learned in detail. Also, techniques which allow machines to function for years instead of months must be discovered. Replacing worn out machines with mostly lunar materials will require some minimum lifetime for the production equipment. If remedies are found to allow a rover to be fully functional for four or more months, it will have been learned that not only are such remedies effective but also that remedies were necessary.
The Advantage of Cooperation
The risks and expense of lunar development are apparent. If the knowledge gained is shared among a group of nations, the expense for each is lessened while the benefit is increased. This provides added incentive to abandon the sort of competition among nations in which each tries to increase its share of resources at the expense of others and become economically dominant. Instead, some mutually beneficial plan of sharing lunar resources could increase the wealth for all. The time until payoff is inconveniently long, but great results are physically possible. This is a test for humanity.
