# Tag Info

42

Long March 11 is a cold-launched rocket, based on a concept popular with military rockets. A gas charge is generated by the launch platform (often using a chemical gas generator) to eject the rocket from the launch platform before engine ignition. This saves the launch platform from having to manage hot exhaust gases, and reduces wear and tear on the launch ...

27

The Queqiao satellite's primary purpose is to relay communications to/from the upcoming Chang'e 4 lander and its rover. However, it also has scientific targets. In particular it carries a joint Dutch-Chinese low-frequency radio antenna to perform deep space astronomical observations. Its position around the Earth-Moon L2 point puts it partially behind the ...

25

China has nothing to prove in this case, as it asked to be part of the International Space Station. This request was shut down by the US Government, which now prevents NASA from working with any Chinese citizen affiliated with the government (e.g. CNSA). This is entirely on the US and its decision to bar the CNSA from any cooperation with NASA, and not on a ...

18

That's unburned $\mathrm{N}_2\mathrm{O}_4$. The zeroth and first stages of the Long March use $\mathrm{N}_2\mathrm{O}_4$ and $\mathrm{UDMH}$. The Dnepr uses the same propellants. I doubt that the red gas you see is from the cold launch system. That system uses a black powder mortar.

15

Yes, there are methods to track and estimate what a payload is up to. Most methods rely on visual or radar to identify the orbit and its parameters. There are many amateurs that do this. Once an object has been located and its orbit calculated, you can then monitor changes in the orbit. Generally these things are public. Imaging the object is generally the ...

14

The Chinese Space Program is largely handled by two entities, China National Space Administration (CNSA) and China Aerospace Science and Technology Corporation (CASC). They are both state agencies with the former handling the planning and the latter, the implementation. A Wired article dated July 1, 2013, and titled, A dragon in space: China's space ...

12

The reason why the launch sites are built inland goes back to the Cold War. Western commentators have expressed surprise at the selection of a launch site so far inland, in difficult terrain, with poor communication facilities in a relatively populated rural area. The Chinese subsequently explained that during the tense seventies, an inland site was ...

11

This is will be a very humble answer and an overview of events that caused the complication. It has been more of a political issue rather than technical issue. U.S. congress always have wanted to ban the Chinese from launching U.S. satellites due to security and financial reasons. (So the money goes to ULA, not Chinese) Back in 1996, Intelsat 708 was ...

11

I was able to find quite a bit in the way of the Chang'e 3 rover's specifications and equipment, so I will only summarize its most interesting features. Power supply: The rover is powered by both nuclear power and solar power, giving it a potential lifespan of approximately 30 years or more, even though its original mission is only for three months. It will ...

10

Surveyor Program landers (1-7) made robotic soft-landing on the lunar surface. The major difference between Surveyor landers and Chang'e 3 is that they didn't orbit the Moon, but were put on a ballistic trajectory and the autopilot computer did the rest. NASA page on Surveyor 1 puts the soft-landing procedure like this: For the landing sequence, an ...

9

The view is horizontal as the spacecraft seems to stop and hover over the chosen site, and then the view pitches forward until it is looking straight down. According to the graph linked by @AlexanderVandenberghe, that pitchover is happening at 6-8km altitude, so I think what you're interpreting as a "stop and hover" is not a hover. It's falling, but the ...

9

There are some great excerpts from the ODPO (Orbital Debris Program Office) at NASA Johnson that describe the results of ASAT operations by China (Fengyun-1C in January 2007) and the U.S. (USA-193 in February 2008). The decision to impact USA-193 while it was nearing re-entry minimized the risk of debris to the ISS and other LEO satellites. According to ...

8

It's pretty rare to see popular news articles get technical details right, and this is no exception. The grid fins referred to in earlier QAs here are, as Polygnome notes, not maneuverable; they just act as passive stabilizers during LES aborts for the shroud-enclosed Shenzhou spacecraft. (See also this QA regarding the Soyuz grid fins.) The new article ...

8

According to Quanzhi Ye (via tweet; while not a primary source, he is planetary scientist who understands Chinese) it is for simulating Mars' lower gravity while testing obstacle avoidance for the Chinese Martian landers. There is some additional information on the testing program for the lander and Long March 5 rocket, which will carry it to Mars, in this ...

7

A lot of information could be gleaned simply from determining the orbit and characterizing the type of electromagnetic radiation it emits. Getting a decent picture of the satellite would also help considerably. For example, a GEO satellite is almost assuredly going to be used for communication or very wide field-of-view remote sensing (e.g. weather, missile ...

7

China did not develop a space program from scratch. Before the 1960 Sino-Soviet split, there was ample cooperation between the Soviet Union and China in rocket development. This can still be seen in the design of their rockets, for example the use of swirl injectors and UDMH as a fuel. A lot of know-how also came from the western rocket development by von ...

7

There are two embodied steps in the question a) "pre-eminent" which raises the question "for what purpose" and b) that "north" does not follow the pattern adopted by other participants. Expanding a little: a) That the crewed Shenzhou missions depart from Jiuquan might make it "pre-eminent" in some points of view. Please say if this isn't what you meant. ...

7

The announcement was first made by the vice principle of Chongqing University (the primary designer of the growth module) on the 15th of January and you can find the original article summary from their university website here (in Chinese of course). The first image is from the lunar module (the actual time the photo was taken was 7th January around 10am). ...

6

To public knowledge, it is the highest-resolution imager in GEO. The 2nd place is occupied by weather sats with instruments like GOCI (https://en.wikipedia.org/wiki/Geostationary_Ocean_Color_Imager), with resolutions around 500m. The thing is there is a compromise to be made between field of view and resolution: at 50m resolution, GF-4 has a 400km field of ...

6

Right now, the Chinese Deep Space Network is only in China, although there are a number of locations there. They are building a station in South America, however, which should give near continuous communication. The setup they have should allow for roughly 16 hours/ day of communication to any deep space object, including Queqiao. Note that the Wikipedia ...

6

According to Spaceflight Now (emphasis mine): Chang’e 4 is expected to enter lunar orbit Tuesday [Dec 11 2018] after a series of course-correction maneuvers, then use braking rockets to descend to the moon’s surface, targeting a landing inside the 110-mile-wide (180-kilometer) Von Karman crater in moon’s South Pole-Aitken basin region in early January. ...

6

Update: This Chinese Journal of Space Science has journal articles in English and it has a lot of technical info and it's incredibly good kuish. Thank you @LarryTeds. Woo. (side note: with this under the belt, there are probably other journals like this, so search something like Chinese Journal of Space Technology might get you a hit.) Aside from that ...

5

I don't know the exact path, but I do know there's a path to the moon that takes about a month. The reason it's used is that it takes less energy. The Apollo missions got there in three days but your economics are different when you are consuming supplies for every day in space. See this question for more information: Low Energy Transfer within Earth-Moon ...

5

Like @LocalFluff mentions in the comment, much of what is circulating the western media in the last few days since news broke out that Yutu is in trouble is unsourced information, but those speculations, however substantiated they might or mightn't be, are regarding its fate and possible procedures to mitigate problems that it encountered, not what the rover ...

5

ISS didn't have many countries as part of it especially China and India IMO have many and varying reason. China is somewhat capable on his own for going on venture like this having space station as you know Tiangong. If you compare space program of China with nations participating in ISS excluding USA, China has far more program running concurrently and ...

5

They're currently looking at two sites in Utopia Planitia. Each landing site will have a landing eclipse of 40 by 100km. This region has a cool feature in; Utopia Planitia may have been extensively resurfaced by mud flows, so it is an interesting place to investigate potential past subsurface habitability. Alfred McEwen This is an edited version of this ...

5

Just checked from the JPL Horizons website. It seems that it is in fact still there. I also looked at the JPL Small-Body Database. Looking up Toutatis, it says it was last updated in 2003. It seems very unlikely that it was specifically deleted because China wanted to send a spacecraft there.

4

A Honda Civic is a two axle vehicle. It can tow a trailer. When it's towing a trailer, Civic-plus-trailer is functionally a three axle vehicle. There's no essential difference between a spacecraft with propulsion and a rocket stage. In this case, Long March 5 is a two-stage rocket because it's designed and built separately from the YZ stage. Long March ...

4

Queqiao carries two cameras: According to this Xinhua report (Chinese) following the launch, Queqiao, "carries two cameras, one large and one small. The small one will observe how the satellite antenna opens, and the large one can take group photos of the Moon and the Earth." Annotated version of your first photo: So this photo is from the ...

4

Question: What are the stated or otherwise likely future uses for this space station beyond servicing China's upcoming Chang'e 4 mission and Queqiao satellite on it's way to the Moon? The article "China Builds Space-Monitoring Base in the Americas" (The Diplomat, May 24, 2016) explains many things and has really great photos of China's military base in ...

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