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  (Source: China News)
China will be only the third nation to achieve a soft lunar landing, joining the U.S. and Russia, if it succeeds

Forget the mile high club, the Lunar lander club is a truly elite group.  Only two countries -- the U.S. and Russia -- at the height of their Cold War era prowess managed to land a Lunar rover.  Russia required 21 launches, including 11 failed lander launches, before it accomplished a soft landing with Luna 9.  

I. The Launch

China is trying to achieve a soft landing in only 3 launches; and its efforts may be as much as three years ahead of schedule.  We already chronicled the history of China's overachieving space program, which was born in the early 1990s under later Prime Minister Deng Xiaoping administration.

On Dec. 2, the China National Space Administration (CNSA) launched its first attempt at a Lunar soft landing.  The probe -- Chang'e 3 -- took off from the Xichang Satellite Launch Center.

The Chang'e 3 orbitter -- named after the mythical Chinese goddess who in traditional Chinese legends lived on a palace on the Moon -- is being carried onboard a Long March 3B Y-23 rocket. 

First fielded in 1996, the Long March 3B is the world's second most capable launch platform, at present, behind only Russia's Proton rockets.  It has only failed a pair of times in 10 launches (once fully, and once partially, early in testing); a heavier followup 2007 design, the 3B/E, has never failed in 15 launches.
Long March 3B
China's Long March 3B [Original Source: Unknown]

The Long March 3B is boosted initially by four strapped on boosters rockets which contain N2O4 (nitrogen tetroxide) and UDMH (unsymmetrical dimethylhydrazine) (the same chemistry used by Russia in its Proton boosters).  The main rocket has three stages; the first and second stage to detach also use a N2O4/UDMH mix; the third stage uses a mixture of hydrogen (H2) and liquid oxygen (O2) fuel.

The Long March 3B is capable of carrying payloads of up to 5,100 kg (11,000 lb) into Earth orbit.  The launch vehicle -- containing both the orbitter and the lander -- is only 3,800 kg, to allow it to escape Earth orbit.  The lander is 1,200 kg (2,600 lb), while the rover is 120 kg (260 lb), for a total landing weight of 1,320 kg (2,860 lb).

China Chang'e 3 launch
The Moon probe launch was succesful late last week, but debris destroyed at least one unoccupied Chinese home. [Image Source: Getty Images]

The launch was not without incident.  As is often done in these launches, villages in the rocket's trajectory were evacuated as a precaution in case debris fell during the launch -- a lesson that China learned the hard way after the initial failure of the first Long March 3B rocket showered a village with debris, killing several people.
 
China Chang'e 3 launch plan
China's Chang'e launch will use the three-stage Long March 3B rocket. [Image Source: China News]

The evacuation of villages in the Hunan province proved fortunate as a number of debris showered down on local villages as the first stage of the rocket fell off.  One piece was the size of a desk and destroyed a home, Donnie Darko-style.  Fortunately, no one was home, thanks to the evacuation.

China Chang'e 3 path
China Chang'e 3 launch path and planned orbit [Image Source: China News]

The launch itself, however, was not affected by this ejection.  Below is video of the launch and early engine firing video,


It went off without a hitch, and four days later on Dec. 6 (last Friday) the lander + orbitter entered Lunar orbit. 

China Chang E
Chang'e 3 reached orbit last Friday. [Image Source: Xinhua]

China's space agency has been preparing ever since for the Lunar landing.

II. The Landing

The landing follows the traditional thuster assisted strut-based approach that previous U.S. and Russian missions used.

The lander itself is powered by a radioisotope heater unit (RHU), which both powers the onboard hardware (instruments, communications equipment) and keeps the onboard circuitry from contracting and being damaged by the frigid Lunar night, which even at the warmest region (the Lunar equator) can reach 123 K (-150 ºC) [source].  CNN is reporting that temperature in the crater-plane dips to just 93 K (-180°C; -292°F) at night.

The Chinese lander is expected to touch down in the "northern" crater-plane Sinus Iridum (Bay of Rainbows), which features basalt soil.

Sinus IridiumSinus Iridium
Sinus Iridium, the expected northern landing site [Image Source: NASA]

The landing attempt will occur tomorrow at around 3 p.m. GMT (10 a.m. EST).

Post-landing the order of activities (according to Planetary.org's translation of the below image) will be:
  • Deploy solar panels
  • Establish communications
  • Unlock rover
  • Deploy rover mast and panels
  • Create panorama for rover navigation
  • Move to surface (about 350 minutes)
  • Do local exploration (about 30 minutes)
China Chang'e 3 landing
Chang'e 3's landing plan [Image Source: China News]

If the landing is successful (as mentioned Russia and the U.S. failed in initial soft-landing attempts) the lander will deploy the rover, which is named Yutu, which means "Jade Rabbit" (roughly) in Chinese.  The name comes from a white bunny who in Chinese legends was a pet of the Lunar Godess.

Chang'e 3 render
Chang'e 3 and Yutu are shown in a render. [Image Source: CNSA]

The rover is expected to explore a 3 km2 area during the 3-month mission, digging up soil, analyzing soil samples, and transmitting real time video during its daytime travels.  The rover is powered by a solar panel and stands 1.5 m (4.9 ft).
 
The rover descends
An artist rendering of the rover rolling out of the lander. [Image Source: China News]

Perhaps the most crucial aspect of the rover's onboard equipment will be the ground penetrating radar, which will be able to study the depth and structure of the lunar soil, up to a depth of 30 m (98 ft). 
 
China Chang E explained
Jade Rabbit is a digger. [Image Source: The Hindu Times]

The radar is also expected to penetrate down several hundred more meters into the lunar crust, giving new insight into the composition of the Moon.  The chemical composition of soil dug up by the rover will be examined using an alpha particle X-ray spectrometer and an infrared spectrometer.
 
Chian Yutu Rover
An artist rendering shows Yutu roving the Lunar plain. [Image Source: CNSA]

The lander will use extreme UV cameras to study the affects of solar activity on the ion layer surrounding the Earth.

The U.S.National Aeronautics and Space Administration (NASA) is expecting the landing will interfere with its Lunar Atmosphere and Dust Environment Explorer (LADEE) experiment, but may offer some interesting insight into how water from probes compares to observed Lunar water deposits believed to be native.  LADEE and the U.S. Lunar Reconnaissance Orbiter (LRO), which the U.S. launched in 2009, will observe the landing from orbit.

III. What Came Before

It's been just six years since China launched its first Moon mission.  In 2007 China achieved its first major Lunar milestone, successfully launching an orbiter -- Chang'e 1 -- which used a laser altimeter to produce the most accurate 3D map of the Lunar surface to date while it orbitted 100 km above the Lunar surface.  At the end of the mission, China directed it into a controlled crash on the Lunar surface.

Chang'e 1
Chang'e 1 orbited the Moon for over a year before being directed into a controlled crash.
[Image Source: China Daily]

In 2010 a second Lunar orbiter, Chang'e 2 carried out a similar orbital mission, flying in a 100 km orbit.  It cut Chang'e 1's travel time from 12 days to 5 by adding to more boosters to its delivery rocket.  It also added an even more precise laser altimeter, capable of mapping the lunar radius to 5 meters and more points of data thanks to a 5 fps (frames per second) pulse resolution (versus 1 fps for its predecssor).  Its main camera was bumped to a resolution size of 10 meters, versus 120 m in the original.

Chang'e 2's high resolution map can be explored here.  It's in Chinese, but you can use Google Translate to translate terms in the features drop down (planes, landing sites, etc.)

Here's some handy comparison images with the LRO.

China LRO v. Chang'e 2



LRO v. Chang'e 2



LRO v. Chang'e 2
(Top images are Chang'e 2, with the low-res parts coming from the camera, prior to laser-scanning; lower images are from LRO.) [Image Source: Planetary.org via NASA/CNSA]

After effectively serving as a scout for potential landing sites of Chang'e 3, Chang'e 2 successfully boosted out of Lunar orbit.

Chang E 1 and 2
Chang'e 2 was bigger, better, faster, [and] stronger than Chang'e 1. [Image Source: China Daily]

It completed a fly-by of the asteroid 4179 Toutatis, an asteroid that frequent crosses near the Earth's orbit and is expected to come very close to the Earth in 2069.  The asteroid has an estimated mass of 5e13 kg -- roughly the mass of a 3 km high mountain.

The fly-by occured at the Earth-Sun L2 point, and the Chang'e 2 probe passed within 3.2 km of the asteroid.  The asteroid is about 4.5 km at its widest point.

Asteroid 4179
3D models of 4179 Toutatis [Image Source: Wikimedia Commons]

Should it ever collide it will likely split into two roughly 2 km chunks of porous sedimentary rock, each of which would produce a roughly 200,000 megaton explosion, producing two roughly 20 kilometer impact craters, according to calculations made via the Imperial College of London and Purdue University online impact calculator.

That's not likely enough to cause the extinction of man (by contrast the dinosaur-killing asteroid that made the Chixulub crater in the Yucatan had an estimated impact energy of 100 million megatons -- or roughly 500 times more energy.


China became only the fourth space agency to do a fly-by on an asteroid.  NASA, the Japanese Aerospace Exploration Agency's (JAXA), and the European Space Agency (ESA) have all performed similar fly-bys.  China's fly-by was the closest for a non-landing mission.

Chang'e is currently travelling in deep space away from Earth, approaching 1e8 km (~0.67 AU) away next year.  It is expected to reach about 3e8 km away from Earth (2 AU) -- putting it close to the asteroid belt and midway between the Earth and Jupiter.  This deep space mission is serving as a test for China's deep space communications technology, which could be used for future missions to Mars, the Asteroid belt, or Jupiter's moons.

The Chang'e probes are built by the state-owned contractor China Aerospace Science & Technology Corp. (yes, the Chinese gov't contracts itself). Chang'e 1 was estimated cost CN¥1.4B ($230M USD); Chang'e 2 cost CN¥900M ($148.2M USD).  The cost of the Chang'e mission has not yet been revealed, according to China's Xinhua news agency.

(A point of comparison: the LRO cost U.S. taxpayers roughly $580M USD, more than twice the cost of either probe.)

IV. What Comes Next

A backup to Chang'e 3 (Chang'e 4) is schedule for a 2015-2016 launch.  After the soft landing, the next major step in Chinese Lunar exploration will be the Chang'e 5 mission, which will try to return Moon rock samples to Earth.

China Yutu
A mockup of Yutu is displayed to the press. [Image Source: Facebook/HuffPost]

While the U.S. achieved manned Lunar sample collection, only Russia achieved robotic Lunar sampling, with its Luna 16, 20, and 24 missions.  Luna 24 (1976) collected the most rock of the three missions -- but only about 170 g.  While the Chinese lander won't collect as much as American manned missions did (up to 111 kg), it will substantially surpass the Russians, collecting (at least) 2 kg.

A Chang'e 5 mockup
A Chang'e 5 mockup [Image Source: China Daily]

That mission, which will use the heavier Chang Zheng 5 next-generation rocket will also operate slightly differently from its manned/unmanned foreign predecessors in terms of Earth return.  The Russian sample rockets launched directly to Earth. 

The Chinese lander module will deorbit similar to the Apollo landers, redock with an orbiter and returning to Earth.  However, unlike the U.S. missions, which required manned manual docking, the planned lander will automatically robotically dock with the orbitter, a first in Lunar exploration.

Sources: Xinhua, CNN, CCTV on YouTube, Planetary.org [NASA impact]



Comments     Threshold


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It looks like a huge...
By Spookster on 12/13/2013 6:08:26 PM , Rating: 5
Radar Operator: Colonel, you better have a look at this radar.
Colonel: What is it, son?
Radar Operator: I don't know, sir, but it looks like a giant...
Jet Pilot: Dick. Dick, take a look out of starboard.
Co-Pilot: Oh my God, it looks like a huge...
Bird-Watching Woman: Pecker.
Bird-Watching Man: [raising binoculars] Ooh, Where?
Bird-Watching Woman: Over there. What sort of bird is that? Wait, it's not a woodpecker, it looks like someone's...
Army Sergeant: Privates. We have reports of an unidentified flying object. It has a long, smooth shaft, complete with...
Baseball Umpire: Two balls.
[looking up from game]
Baseball Umpire: What is that. It looks just like an enormous...
Chinese Teacher: Wang. pay attention.
Wang: I was distracted by that giant flying...
Musician: Willie.
Willie: Yeah?
Musician: What's that?
Willie: [squints] Well, that looks like a huge...
Colonel: Johnson.
Radar Operator: Yes, sir?
Colonel: Get on the horn to British Intelligence and let them know about this.




doh
By Jeffk464 on 12/13/2013 8:20:03 PM , Rating: 2
Hey, I think they got the plans for our rovers.




RE: doh
By delphinus100 on 12/13/2013 10:42:20 PM , Rating: 1
Though there was a concept for a robotic US Lunar Rover called 'Prospector,' it never flew. We have put four different ones on Mars, two of which currently function.

However, the 'roving' vehicles that the US did put on the Moon, had local drivers...


priorities
By superstition on 12/15/2013 4:04:18 PM , Rating: 2
They have massive air pollution that some experts say is worse to breathe than the air at ground zero, rivers of garbage, melamine in milk, arsenic/cadmium/lead/mercury in various foods -- including foods they export (like what goes into protein powders and garlic), and more.

Let's go to the moon!




RE: priorities
By Nephiorim on 12/16/2013 5:33:19 AM , Rating: 1
If we wait around until all the earthly problems are solved before looking to the stars we're pretty much doomed. There will always be fires to put out. As Neil DeGrasse Tyson put it (paraphrasing here) we need a common goal to inspire (new) generations to become techies/scientists, to improve quality of life. If you don't know where you're going and/or are purely focused on the here and now it's easy to say fuck it (or fuck the planet). Part of the problems you're describing is solved by better educating people. You do that by providing access to better education and motivating people to want to get better educated. Space exploration is one (imo pretty important) avenue to accomplish this.


Just got a message...
By The Insolent One on 12/13/2013 7:48:02 PM , Rating: 2
Hello NASA, a Mr. "Cats" just called. He said:

"All your base are belong to us."

He declined to leave his number.




moonshot as a symbol
By sallyladdy on 12/14/2013 12:01:04 PM , Rating: 2
I think the point is how amazing for mankind it is that we got to the moon again. I wonder how the "moonshot" became that metaphor for human achievement - Of course GOOG uses that word a lot. I recently worked on a US startup animation video that uses the Moonshot as a symbol for empowering and supporting dreams. http://bit.ly/19JBNjJ
Such a potent symbol.
How it must feel up there alone, with nothing at all around you. "Be simple and rediscover the world" (Dostoyevsky). #jaderabbit #moon #landing




Sure they are ahead of schedule
By sweetca on 12/14/2013 2:51:51 PM , Rating: 2
All you need is some R&D and smart people working around the clock to come up with innovative... Oh, wait.

All you need is dedicated spies who steal and officials who bribe away technology secrets from the countries that worked hard to come up with the innovative... Yeah, this one is better.




By Fujikoma on 12/14/2013 4:25:20 PM , Rating: 2
I think it's great that another country is also shouldering exploration costs. Regardless of the politics, science will win out in the end.




One small roll for rover.
By drycrust3 on 12/14/2013 7:21:33 PM , Rating: 2
Here is a link for a China Daily web page which includes a video of the ramp being lowered and then Yutu rolling off onto the moon's surface. There seems to be a crater and some debris in the background, but I'm not sure if that is from this mission or not.
http://www.chinadaily.com.cn/china/2013shenzhoux/2...




?
By Bubbacub on 12/15/2013 4:17:38 AM , Rating: 2
First of all - congrats to the Chinese space agency - this is a pretty neat achievement.

Secondly this sentence:

"Long March 3B is the world's second most capable launch platform, at present"

What does that mean?

Capable in terms of
1. Mass to LEO
2. Mass to GTO
3. Mass to TLO

Or is that cost per kg to either of those three destinations?

For the first three cases it clearly isn't the second most capable rocket, proton, ariane, atlas v, h2 and delta iv are all much more capable heavy lift rockets.

If you are looking at cost per kg to LEO, its hard to beat the costs of falcon 9 and the Indian plsv.

In any event the outdated hypergolic nastiness that is the long march 3 rocket is not the second most capable rocket in any meaningful category that I am aware of.

Good article though - enjoyed it!




Stolen technology
By greijing on 12/14/13, Rating: -1
RE: Stolen technology
By greijing on 12/14/2013 12:18:06 PM , Rating: 2
I meant to add that, china didn't have the capital until literally in the last five years. They never had the capital before that. Because they spent what they had on fixing up their infrastructure. So, theft is the only explanation as to how they can now do this.

Thieves.


RE: Stolen technology
By wordsworm on 12/14/2013 12:41:45 PM , Rating: 2
Everyone knows that the USA and USSR both got their science from Germany post WWII.


RE: Stolen technology
By Divide Overflow on 12/14/2013 7:56:56 PM , Rating: 2
Yeah, because US rocket scientists like Robert Goddard are just a myth.


RE: Stolen technology
By JediJeb on 12/16/2013 1:05:45 PM , Rating: 2
Robert Goddard got us started with rockets, but Wernher von Braun got us to the moon.(He was German by the way)


RE: Stolen technology
By ClownPuncher on 12/16/2013 11:58:14 AM , Rating: 2
Some of it.


RE: Stolen technology
By drycrust3 on 12/14/2013 3:07:02 PM , Rating: 2
Saying China could have only done this by stealing is, to me, a shallow accusation because no one can achieve a soft landing on the moon (well, at present anyway, one day it will be just like catching the bus to downtown) without a huge range of resources and skills, many of which are commercially available all around the world. Notice that "many of which are commercially available all around the world" bit? It means China bought stuff on the open market to make this possible. Is it stealing when you buy stuff on the open market? For example, we saw pictures of people at the Chinese control centre using computer monitors with computer keyboards, were those stolen? I have no idea, but I think they were bought. I can't imagine the President of China approving of the use of stolen materials or information on a project of national prestige when such materials or information is available commercially.
Maybe it seems strange to you that China could do this stuff so quickly, but that is because you underestimate China. President Kennedy gave America a decade to land a man on the moon, and they did it, so why can't China have done it in a decade too? Or maybe, since the technology is much more common place now, China saved themselves a few years by buying more of what they needed. Is that stealing?
Soft landing on the moon (as against just firing a rocket in that direction) isn't just about having enough money to do it, it isn't just about having the technology to do it, it isn't just about having the mathematical and scientific and engineering skills to do it, it isn't just about having the infrastructure to support it, it isn't just about the political will to do it and support it, it is all about a complete integration of the whole package of skills, technology, money, infrastructure, and political will to do it. That is what China has done and this proves it.


RE: Stolen technology
By Bubbacub on 12/15/2013 4:20:15 AM , Rating: 2
Oh well I guess the first ever development of rocket technology by mankind wasn't Chinese then...........

http://en.m.wikipedia.org/wiki/Rocket


RE: Stolen technology
By JediJeb on 12/16/2013 1:10:28 PM , Rating: 2
quote:
All this is possible due to theft. Except for the US, Russia and Japan, no other country can do any of this without a) stealing or b) help from thieves. It took the American almost 40 years to develop the technology and figure out how to get the thing off the ground without blowing up. N Korea and china does this in less than 10 years? Really? Like I said before, nothing ever good come out of china. Fact. Ask the Internet.


It is also a fact that during the late 90s the Clinton administration sent scientist to China to help them develop their missile technology. I wouldn't call it stealing when we actually gave them help.


WWMBD?
By Reclaimer77 on 12/13/13, Rating: -1
Screw China
By TechIsGr8 on 12/14/13, Rating: -1
JOBS REQUIRED........
By marloloh on 12/15/13, Rating: -1
ESA assist
By Nephiorim on 12/14/13, Rating: -1
RE: ESA assist
By vxmqzz on 12/14/2013 8:46:36 AM , Rating: 2
ESA only provided 30 mins tracking,that's it


RE: ESA assist
By Nephiorim on 12/14/2013 9:01:46 AM , Rating: 2
quote:
Immediately after liftoff, ESA’s station in Kourou, French Guiana, will start receiving signals from the mission and uploading commands on behalf of the Chinese control centre.

The tracking will run daily throughout the voyage to the Moon. Then, during descent and after landing, ESA’s deep-space stations will pinpoint the craft’s path and touchdown.

Or you could read the URL provided. Even if it was 30 minutes combined it was still 30 minutes the Chinese couldn't do it alone. And tracking etc (& routing commands) during the landing phase is pretty critical.


RE: ESA assist
By dsumanik on 12/14/13, Rating: -1
RE: ESA assist
By Jeffk464 on 12/14/2013 10:33:03 PM , Rating: 3
The US recently put one on mars, what are you talking about.


RE: ESA assist
By Nephiorim on 12/15/2013 3:55:08 PM , Rating: 2
I'm European, but yeah whatever bro :)


RE: ESA assist
By Dorkyman on 12/16/2013 12:32:24 AM , Rating: 2
Golly, what an absurd rant. Bad case of the envies.


RE: ESA assist
By firepower on 12/14/2013 10:16:57 AM , Rating: 6
The USA and USSR both had assistance as well with costrol and tracking.
Australia's Parks Radio Telescope was used in the Apollo missions, and I know the UK assisted the USSR.

http://en.m.wikipedia.org/wiki/Parkes_Observatory

"During the Apollo missions to the moon, the Parkes Observatory was used to relay communication and telemetry signals to NASA, providing coverage for when the moon was on the Australian side of the Earth"

I am sure there would have been more assitance, these examples are one i know about.

China doing a great job to do this and at lower cost, obviously they using a lot of knowledge from previous flights and have much more modern hardware and software than original USA and USSR flights.


RE: ESA assist
By Solandri on 12/14/2013 2:29:26 PM , Rating: 4
quote:
"During the Apollo missions to the moon, the Parkes Observatory was used to relay communication and telemetry signals to NASA, providing coverage for when the moon was on the Australian side of the Earth"

Yeah, it's important to realize that while the same side of the moon always faces the Earth, the Earth itself rotates and no single country always faces the moon. You must have cooperation from other countries if you want to maintain constant contact with anything you send to the moon (or anywhere in space other than geosynchronous orbit).

NASA has a fleet of communications relay satellites up which allowed them to stay in contact with the Shuttles and the ISS 24/7. But they aren't very useful for the low signal strength communications from distant locales like the moon and Mars. For those, you need the big dishes to detect the signal from amongst the noise.


RE: ESA assist
By jvillaro on 12/14/2013 11:37:07 AM , Rating: 2
So?


"Google fired a shot heard 'round the world, and now a second American company has answered the call to defend the rights of the Chinese people." -- Rep. Christopher H. Smith (R-N.J.)

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