Chang'e 3 may launch December 1 with Yutu rover, will not harm LADEE mission
Posted by Emily Lakdawalla
27-11-2013 24:20 CST
Yesterday the Chinese space agency held a press briefing about the Chang'e 3 lunar lander. They announced that the rover has been named Yutu (or "Jade Rabbit," a legendary companion of the goddess Chang'e). Yutu was selected from a list of 10 names, receiving 649,956 votes out of nearly 3.5 million votes cast. In a written statement that I'm decoding with the help of Google Translate, they remark that the name Yutu embodies Chinese traditional culture and reflects their intent for peaceful use of space, and that they're looking forward to the rover rolling across the Bay of Rainbows. Chang'e 3 will launch on a Long March III B onto a direct lunar transfer orbit (an orbit with perigee 200 kilometers and apogee 380,000 kilometers).
Strangely, the press briefing did not include a mention of a specific launch date and time. Via NASAspaceflight.com I can convey a rumor that it may be launching December 1. The rumor comes from a member of the forum's personal communication with a friend who knows someone at the Xichang launch site, so I wouldn't set my watch by it, but I'll report it in case it turns out to be true:
The launch may take place on December 2, 2013 between 1 and 1:30 a.m. China standard time (December 1 at 9:00 PT / 17:00 UT), with lunar orbit insertion on December 6 at 10:30 (December 5 at 18:30 PT / December 6 at 2:30 UT), and landing on December 16. A subsequent post points to a 2008 paper that states that a landing on December 16 would occur at 12:36 UT.
Google Translate is a great tool but it is not quite good enough for me to be confident about its translations of Chinese text. So I am very grateful for the help of Dr. Yong-Chun Zheng of the Chinese National Astronomical Observatories, who helped me improve upon Google Translate to understand some key parts of the press release and a subsequent online Q and A session.
China has significantly expanded its network of ground stations for the deep-space communications required to support a landed lunar mission -- and perhaps more missions beyond that. From their translated statement (emphasis mine):
In order to command the driving path of the lunar rover, our country has established a deep space surveying and control network. We built a new ground station equipped a large antenna with 66 meters in diameter in Jiamusi, northeast China, a ground station equipped a large antenna with 35 meters in diameter in Kashgar, Xinjiang, northwest China. We built an observatory equipped a large antenna with 65 meters in diameter, to serve for the Very Long Baseline Interferometry (VLBI).... By building these ground stations, the current ability of China’s Measurement, Control and Communication Technologies for space exploration is almost the same level with the world. We not only have the capability of measurement for lunar missions, but also lay the foundation for future deep space exploration, such as future Mars missions.
Since the Mars Orbiter Mission launched from India, there has been much chatter in the international media about a space race between India and China. A reporter asked about that. Here's the response:
About lunar exploration, the United States has already achieved manned landing on the Moon. The former Soviet Union has achieved robotic sampling and returning to the Earth. The goal of Chang'e 3 is to achieve a soft landing on the Moon.
I take this to mean that if China were seeing itself in competition with anybody, it would be with the U.S. and Russia; but the U.S. and Russia accomplished this lunar exploration a long time ago. Clearly China is not competing with these other nations in that sense. What India is attempting has little to do with what China is currently attempting. They went on to say, regarding the Mars Orbiter Mission:
On behalf of my colleagues in China, I congratulate India’s successful launch. India's probe needs to be accelerated beyond Earth orbit, and finally go into orbit around Mars. According to current plans, the probe will arrive at Mars in September, 2014. The process of achieving orbit around Mars is difficult. If India can successfully realize orbit at Mars, it is indeed a great achievement, both for India and for international cooperation. As Chinese colleagues, we wish them success.
Very gracious. Finally, about "space races" and international space exploration in general:
In fact, we have no desire to race with any country. China has its own space program. We are realizing our own plans step by step. Our goal is to use space peacefully. It is also the consensus of the world. Human beings need to make use of space resources to support sustainable development.
In the last month, the conference of International Astronautical Federation was opened in Beijing. It was a great event in the aerospace industry. The development of China’s space industry has been recognized by the worldwide community. In this conference, the president of China National Space Administration, Xinrui Ma, stated clearly that China's space program is open to the world. International cooperation is encouraged and welcomed. China will have completed our own space station in 2020. Our space station is open to the world. We welcome other countries to use the space station. Similarly, our lunar exploration program is also open to all. We have sincere willingness for international cooperation. [Others are] welcome to join China’s lunar program and work together for future lunar exploration.
Words are important, and I'm glad to hear those words. There's a lot of distrust between the American and Chinese governments, and communication isn't helped by a language barrier that even the lofty powers of Google can't quite surmount. Thank goodness for the help of individuals who sincerely desire international cooperation. If there's one place where international cooperation has triumphed over political divisions, it's in the scientific exploration of our universe. Where official statements pronounce an intent to cooperate, scientists can openly act upon those intentions to share data with each other.
Ironically, the translation help I received from Dr. Zheng came about because of a divisive headline posted on an article by Leonard David on space.com: "China's 1st Moon Lander May Cause Trouble for NASA Lunar Dust Mission." Chang'e 3's landing (scheduled for December 16) will be about six weeks in to LADEE's dust-monitoring mission. LADEE is studying a lunar atmosphere and dust environment that has been disturbed very little since the last Apollo and Luna landings, and Chang'e 3's landing will definitely have an effect that LADEE will be able to detect. Isn't this a problem for LADEE?
Well, it's sort of a problem, but it's more of an opportunity. (Yes, a "crisitunity.") Paul Spudis actually explained this very well in a blog post two months ago (thanks to Richard Elphic for the link):
The coincidence of Chang’E 3 arriving at the Moon after LADEE has begun observations has developed into a serendipitous occurrence for lunar science. Because we don’t understand very well how exospheric gases are added to and removed from the Moon, what has landed in our laps is an unplanned (but controlled) experiment. A known quantity of gases – of known composition – will be added to the lunar atmosphere at a precisely known time, in a precisely known place. One could have not designed a better experiment to measure how this addition of material is distributed, how its distribution evolves over time, and how these expelled gases dissipate into cislunar space. Even better, LADEE will have almost a full month to monitor and characterize the lunar atmosphere before Chang’E arrives, thus allowing us to first observe the “natural” Moon and then the “contaminated” Moon and how the lunar atmosphere recovers from its defilement.
None of this was prearranged – the Chinese schedule their missions on the basis of their own time-table and programmatic needs (just as NASA’s lunar goals have changed over the last 5 years). But because of a fortuitous alignment of schedules, we have a unique opportunity to observe in real time how the Moon works. Hopefully, the Chinese will provide us with detailed mass numbers of their spacecraft and exactly what variety of fuel it carries, but even if they don’t, physics dictates a certain mass and volume of the exhaust gas and its composition will be measured by LADEE (allowing us to know the type of fuel used). China’s December lander mission to the Moon will provide our U.S. mission with a welcome bit of “traffic exhaust,” giving scientists the opportunity to learn more from LADEE than we’d originally envisioned.
Leonard David's article was shared on a lunar science discussion email list subscribed to by researchers all over the world, and the subsequent discussion of how China really wasn't messing things up for NASA provided my introduction to more than one Chinese scientist. Score a point for international cooperation! Even if it came about in a backwards way.
Finally, one more enjoyable anecdote to share about Chang'e 3 and her bunny companion, due to depart for the moon on Saturday. Today a member of unmannedspaceflight.com shared this bit of Apollo 11 transcript, in which Michael Collins tells the moonwalkers to look out for the maiden and her rabbit:
It seems Aldrin and Armstrong were 44 years too early to find Chang'e and Yutu on the Moon.