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China 'lifts mysterious veil' by landing probe on moon's dark side


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China 'lifts mysterious veil' by landing probe on moon's dark side

By Michael Martina

 

2019-01-03T071250Z_1_LYNXNPEF02088_RTROPTP_4_CHINA-MOON.JPG

A model of the moon lander for China's Chang'e 4 lunar probe is displayed at the China International Aviation and Aerospace Exhibition, or Zhuhai Airshow, in Zhuhai, Guangdong province, China November 6, 2018. Picture taken November 6, 2018. Wang Xu/China Space News via REUTERS

 

BEIJING (Reuters) - A Chinese space probe successfully touched down on the far side of the moon on Thursday, the space agency said, hailing the event as a historic first in the country's space program.

 

The Chang'e-4 lunar probe, launched in December, made the "soft landing" at 0226 GMT and transmitted the first-ever "close range" image of the dark side of the moon, the China National Space Administration said.

 

The moon is tidally locked to Earth, rotating at the same rate as it orbits our planet, so its far side - or "dark side" - is never visible to us. Previous spacecraft have seen the far side, but none have landed on it.

 

The landing "lifted the mysterious veil" of the far side of the moon and "opened a new chapter in human lunar exploration", the agency said in a statement on its website, which included a wide-angle color picture of a crater from the moon's surface.

 

The probe, which has a lander and a rover, touched down at a targeted area near the moon's south pole in the Von Karman Crater after entering the moon's orbit in mid-December.

 

The tasks of the Chang'e-4 include astronomical observation, surveying the moon's terrain, landform and mineral makeup, and measuring the neutron radiation and neutral atoms to study the environment of its far side.

 

A MAJOR SPACE POWER

The landing is a milestone for China in its race to catch up with Russia and the United States and become a major space power by 2030. Beijing plans to launch construction of its own manned space station next year.

 

While China has insisted its ambitions are purely peaceful, the U.S. Defense Department has accused it of pursuing activities aiming to prevent other nations from using space-based assets during a crisis.

 

Besides its civilian ambitions, China has tested anti-satellite missiles, and the U.S. Congress has banned NASA from two-way cooperation with its Chinese counterpart over security concerns.

 

As competition accelerates in space, U.S. President Donald Trump seeks to create a new "Space Force" by 2020, as the sixth branch of the military.

 

But the private space race is also heating up, as numerous companies aim to commercialize space travel, such as California-based SpaceX, which has upended the industry with its low-cost reusable Falcon 9 rockets.

 

The United States is the only country to have landed humans on the moon, and Trump said in 2017 he wanted to return astronauts to the lunar surface to build a foundation for an eventual Mars mission.

 

NASA administrators have said people could be put on Mars by as soon as the mid-2030s, with the agency having landed eight spacecraft there, the most recent in November.

 

As soon as 2022, NASA expects to begin building a new space station laboratory to orbit the moon, as a pit stop for missions to distant parts of the solar system.

 

In 2003, China became the third country to put a man in space with its own rocket after the former Soviet Union and the United States, and in 2017 it said it was preparing to send a person to the moon.

 

China completed its first lunar "soft landing" in 2013, but its "Jade Rabbit" rover began malfunctioning after several weeks.

 

(Reporting by Michael Martina; Editing by Paul Tait and Clarence Fernandez)

 
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-- © Copyright Reuters 2019-01-03
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...and transmitted the first-ever "close range" image of the dark side of the moon,

 

Since the radio signal is all but effectively blocked by the mass of the moon, (ie, it is impossible to 'beam' the radio signal towards the earth using a dish antenna or similar directional antenna), I wonder how they achieved this.  Perhaps they have a 'relay' satellite currently orbiting the moon which received the signal from the moon lander and then re-transmitted it back towards earth.

 

Or perhaps we just have to believe them... ????

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36 minutes ago, simon43 said:

Since the radio signal is all but effectively blocked by the mass of the moon, (ie, it is impossible to 'beam' the radio signal towards the earth using a dish antenna or similar directional antenna), I wonder how they achieved this.  Perhaps they have a 'relay' satellite currently orbiting the moon which received the signal from the moon lander and then re-transmitted it back towards earth.

 

Or perhaps we just have to believe them... ????

That was my question as well and I think you already answered it. It's likely that the landing rover was sent from orbiter. 

 

It's really good that new countries are studying space. That way we get more interesting information beamed back to Earth.

 

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Looking at the photo of the model of the satellite in the OP, I see a small microwave dish antenna.  Judging by the size of this dish, I'd say that it operates at millimetre wavelengths ==> highly directional, but can transmit a wideband radio (data/video) signal with very little transmit power required.  That would definitely tie up with an orbiting control and relay satellite which can send control signals to the lander and receive data and telemetry signals back, then send them on to the ground station back on earth when the orbiter comes back into radio coverage on this side of the moon.

 

As an aside, I designed and integrated satellite dishes of this type in a previous career...

alcatel.jpg

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8 minutes ago, NCC1701A said:

do the commies share their info?

AFAIK Chinese were always excluded from International space exploration due USA's concerns. I suppose they'll share their information once they become the rulers of the space.

 

 

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Ah, CNN news just did a report about this lunar landing, and China confirmed to CNN that prior to the landing, they launched a 'relay' satellite that is orbiting the moon and sending back the signals from the lunar lander.

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6 minutes ago, manarak said:

most of the shadows are impossible, including the one on the earth, or better, the missing shadow ????

Possibly, but there's a bigger error, remember the probe is on the far side of the moon.

 

I wonder if the animation came from the BBC or the Chinese.

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52 minutes ago, Crossy said:

Possibly, but there's a bigger error, remember the probe is on the far side of the moon.

 

I wonder if the animation came from the BBC or the Chinese.

 

55 minutes ago, manarak said:

 

most of the shadows are impossible, including the one on the earth, or better, the missing shadow ????

 

Who took the picture?

 

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22 hours ago, DM07 said:

I don't know about you, but I find this fascinating, although I guess, the "Dark Side" might look very much like the "Light Side"...only...a bit ...darker....

I realise you're being facetious, but putting on my pedantic hat, the dark side gets as much sunlight as the "light" side.  It just doesn't get any reflected light from the Earth.

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An interesting (for me) aspect of this project is that it's the first time (AFAIK) that a satellite has been placed in what is probably a long-term orbit around another planet.

 

Sure, many space vehicles and satellites have orbited other planets as part of their mission, but only for a limited amount of time.

 

If China placed this satellite in orbit around the moon, then it will probably stay in orbit for some time, (unless intentionally sent elsewhere..), because the Moon's gravity is much less than the Earth's - so the 'pull' of gravity on the satellite is much weaker.

 

I'm thinking that the orbiting satellite is in a LMO (Low Moon Orbit). If it were in a geostationary orbit above the moon lander, (therefore appearing fixed in position in the sky like a TV channel satellite), then it might still have problems relaying the signals back to the earth because the moon would still form a large region of signal blockage.  (I'm too lazy to do the maths to calculate the altitude of a moon geostationary orbit, and to calculate the dimensions of the blocked region).

 

If it is a LMO, then the orbiting satellite will be receiving the lander's data when it passes overhead, storing it, and then re-transmitting it when the Earth comes into view.

 

A LMO means that the satellite will only be 'visible' overhead the lander for a limited amount of time.  Again, I'm too lazy to calculate this.  Typical LEO (Low Earth Orbit) satellites have a visible 'window' on each pass of about 15 - 20 minutes.

 

Here ends today's Science lesson ????

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6 minutes ago, simon43 said:

An interesting (for me) aspect of this project is that it's the first time (AFAIK) that a satellite has been placed in what is probably a long-term orbit around another planet.

 

Sure, many space vehicles and satellites have orbited other planets as part of their mission, but only for a limited amount of time.

 

If China placed this satellite in orbit around the moon, then it will probably stay in orbit for some time, (unless intentionally sent elsewhere..), because the Moon's gravity is much less than the Earth's - so the 'pull' of gravity on the satellite is much weaker.

 

I'm thinking that the orbiting satellite is in a LMO (Low Moon Orbit). If it were in a geostationary orbit above the moon lander, (therefore appearing fixed in position in the sky like a TV channel satellite), then it might still have problems relaying the signals back to the earth because the moon would still form a large region of signal blockage.  (I'm too lazy to do the maths to calculate the altitude of a moon geostationary orbit, and to calculate the dimensions of the blocked region).

 

If it is a LMO, then the orbiting satellite will be receiving the lander's data when it passes overhead, storing it, and then re-transmitting it when the Earth comes into view.

 

A LMO means that the satellite will only be 'visible' overhead the lander for a limited amount of time.  Again, I'm too lazy to calculate this.  Typical LEO (Low Earth Orbit) satellites have a visible 'window' on each pass of about 15 - 20 minutes.

 

Here ends today's Science lesson ????

Queqiao relay

 

Animated GIF

http://www.planetary.org/blogs/guest-blogs/2018/20180615-queqiao-orbit-explainer.html

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Maybe I have got this wrong but did this post not have a link to a black and white you tube clip about science ? I only watched 1/2 of it - now I can not find the link .... Can anyone help please


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9 minutes ago, rvaviator said:


Maybe I have got this wrong but did this post not have a link to a black and white you tube clip about science ? I only watched 1/2 of it - now I can not find the link .... Can anyone help please


Sent from my iPad using Thailand Forum - Thaivisa mobile app

It was Richard Feynman talking about the scientific method.  I posted that on the New Horizons thread, but it's well worth posting again:

 

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