Chinese rover set to become the sixth lunar roving vehicle
Having successfully entered a 62-mile-high orbit around the Moon on December 6 (Beijing time), China’s Chang’e 3 spacecraft is being prepared for a lunar landing attempt currently scheduled for Dec. 15. Once on the ground, the spacecraft will release a rover, called Yutu, which, if everything goes according to plan, will become the third robotic rover, and the sixth roving vehicle in all, to explore our nearest celestial neighbor.
The Soviet Union pioneered the use of extraterrestrial rovers with their Lunokhod program. Lunokhod was originally intended to carry out survey work in support of the USSR’s manned lunar program. When the US won the race to land humans on the Moon, the Lunokhods were retasked to do purely scientific investigations.
The first spacecraft in the series was lost when its launch vehicle exploded seconds after lift-off on Feb 19, 1969. However, the following year, Lunokhod 1 became the first rover to make it safely to another world when its carrier craft, Luna 17, soft-landed in Mare Imbrium on Nov 17, 1970.
A little over two years later, Lunokhod 2 arrived on the Moon aboard Luna 21, landing in Le Monnier crater on Jan 15, 1973. Lunokhod 2 covered 23 miles over a 4-month period – more than three times as far as its sister craft. Both vehicles sent back photos, among which were panoramic views, and carried out measurements using a battery of instruments, including a spectrometer, radiation detector, magnetometer, and X-ray telescope.
Sandwiched in time between the only two Lunokhods to reach the Moon (a fourth member of the series was never launched) were the three crewed rovers of Apollo’s 15, 16, and 17. The Lunar Roving Vehicle was one of the great engineering triumphs of the Apollo Program, allowing astronauts to travel a total distance of about 56 miles from their parked Lunar Excursion Modules. The rovers were designed with a top speed of about 8 mph, although Eugene Cernan, commander of Apollo1 7, reached 11.2 mph – the current (unofficial) lunar land-speed record.
Now comes Yutu (“Jade Rabbit”), which is about to be taken to the lunar surface by its mothership, Chang’e 3. The six-wheeled, 260-pound rover bears a passing resemblance to the slightly larger NASA Mars Explorations Rovers, Spirit and Opportunity, and carries similar instruments, including panoramic cameras and and two spectrometers, one of which works in the infrared, the other (APXS) using alpha particles and X-rays. A robotic arm will enable Yutu to position the APXS near geological targets.
Although the Chinese rover has no drill, it is equipped with a ground-penetrating radar which, together with its spectrometers, will allow it to investigate the make-up of the soil and probe the lunar crust down to a depth of nearly 100 feet. Six cameras – two panoramic and two navigational, all fixed to the vehicle’s mast, and two hazard avoidance cameras, on the lower front of the rover – will be used to capture images, including possibly live video, and also help prevent the robotic explorer from running into objects that might damage it.
Dr. David Darling is an astronomer and author of numerous books, including We Are Not Alone, Megacatastrophes, The Complete Book of Spaceflight, and his latest, The Rocket Man. His website, The Worlds of David Darling, is one of the largest and most visited science resources on the Internet. Darling is a renaissance man, he is a musician, noted author and journalist and serves as our science writer. Darling provides The Spaceflight Group with articles detailing what he knows best - space exploration.