The American LADEE probe has already entered orbit around the Moon to investigate its barely existing atmoshere and dust envelope while the first Chinese lander will liftoff in one and a half month to our celestial companion. Its arrival will mark the end of the 37-year-long hiatus since the last human-made object soft landed on the Moon.

The Chang'e-3 rover on a field test in the Kumtag desert last year.

The Chinese Chang'e-3 mission is getting close to liftoff. We now have an official launch date: the probe will leave from Xichang on the 1st of December, 2013. Press coverage of the mission that will land a human-made object softly after four decade is quite infrequent outside China so far. But China is preparing for the historical event.

The large question mark asks: what shall we call the rover?

The mission will land two spacecrafts on the surface: a static lander and a rover. The latter remained anonymous so far, or rather was simply called 'the Chang'e-3 rover' which is not that inspirative to be honest. Hence a naming contest was launched at the end of September to let the public nominate names. The ideal name “should express the wishes of Chinese at home and abroad, feature the modern and national traits to inspire people.” We're really looking forward for the selection!

But getting to the Moon and landing on it is not that simple. Here is the flight plan for Chang'e-3:

Chang'e-3 is not the only spacecraft humanity is sending to the Moon in 2013: in fact, our newest emissary, the LADEE probe is already orbiting it. As an extra complication, the orbital insertion coincided with the safe mode event of the US federal government when nothing but the most vital functions were operational. Thankfully, a few NASA activities, including the LADEE orbital insertion were deemed “essential” and could still proceed.

LADEE is currently orbiting at about 250 km altitude, much higher than the final, 50 km science orbit. The main activity during the gradual altitude decrease in the first month will be the testing of its laser communications unit. Laser communication is somewhat different than using radio waves: the infrared laser beam is much thinner so the ground station will scan the patch of sky where the probe is expected. When the receiver intercepts the beam, it sends back an answer. Once the two sides acquire signal lock, however, transmission rates can far exceed that of radio waves: downlink from the Moon can reach 620 Mbps while uplink can go up to 20 Mbps. If the demonstration goes well, NASA may consider putting laser comm technology on its 2020 Mars rover, extending broadband connections all the way to the red planet.

László Molnár