Author Topic: Chang'e 5  (Read 3402 times)

Offline Jason Thompson

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Re: Chang'e 5
« Reply #30 on: December 02, 2020, 06:43:13 AM »
Quote


Sorry, I meant specifically the drill samples. They're talking about drilling down 2 metres. So does that mean they're planning to somehow shoehorn a 2 metre sample tube into their ascent vehicle, or drill out shorter segments, or something else? Apollo 15 drilled down a little further, and it's been easy to explain how it simply wasn't practical for the robot technology of the time to retrieve such a long sample and transport it back to Earth - hence the need for astronauts.

So how is Chang'e 5 going to do something which required people at the time of Apollo?

So how is Chang'e 5 going to do something which required people at the time of Apollo?

This was solved by Luna 24. The drill had a bag attachment and the sample was coiled up inside the return module.

https://curator.jsc.nasa.gov/lunar/lsc/luna24core.pdf
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Offline Zakalwe

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Re: Chang'e 5
« Reply #31 on: December 02, 2020, 09:22:10 AM »
I'm curious to see how they store the drill samples - pointing out the difficulty of doing that robotically has long been part of my process of explaining how we know the Apollo samples were collected by people and not robots.

I always considered it to be a question of scale. Robotically collected Lunar samples were returned to Earth by the Soviets in the 1970s.. However they collected something like 380 grams. The Apollo samples had a total mass of three orders of magnitude higher.

Sorry, I meant specifically the drill samples. They're talking about drilling down 2 metres. So does that mean they're planning to somehow shoehorn a 2 metre sample tube into their ascent vehicle, or drill out shorter segments, or something else? Apollo 15 drilled down a little further, and it's been easy to explain how it simply wasn't practical for the robot technology of the time to retrieve such a long sample and transport it back to Earth - hence the need for astronauts.

So how is Chang'e 5 going to do something which required people at the time of Apollo?

Gotcha.Thanks for the correction.
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Offline JayUtah

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Re: Chang'e 5
« Reply #32 on: December 02, 2020, 11:56:39 AM »
One of Apollo's problems, I recall, was that the core sampler would get stuck.  The astronauts would have to wiggle it around and do other non-robot stuff to get the drill to operate again.  Contingencies like that are notoriously difficult to engineer for because you often don't know you have a problem until your robot is in the environment.
"Facts are stubborn things." --John Adams

Offline bknight

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Re: Chang'e 5
« Reply #33 on: December 02, 2020, 02:36:02 PM »
One of Apollo's problems, I recall, was that the core sampler would get stuck.  The astronauts would have to wiggle it around and do other non-robot stuff to get the drill to operate again.  Contingencies like that are notoriously difficult to engineer for because you often don't know you have a problem until your robot is in the environment.

Yes I remember the videos of the drilling operation.  Perhaps a more powerful motor may have been able to penetrate deeper.  Of course that would mean more torque at the astronauts hands, that they may not have been able to combat.  I hope that the system was built with the Apollo history built in.
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Offline Jason Thompson

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Re: Chang'e 5
« Reply #34 on: December 02, 2020, 02:40:13 PM »
One of Apollo's problems, I recall, was that the core sampler would get stuck.  The astronauts would have to wiggle it around and do other non-robot stuff to get the drill to operate again.  Contingencies like that are notoriously difficult to engineer for because you often don't know you have a problem until your robot is in the environment.

“Look at that baby go!”

*beat*

“Look at that baby stop....”

Charlie Duke on Apollo 16 I believe, when the drill encountered a rock a couple of feet under the surface.
"There's this idea that everyone's opinion is equally valid. My arse! Bloke who was a professor of dentistry for forty years does NOT have a debate with some eejit who removes his teeth with string and a door!"  - Dara O'Briain

Offline JayUtah

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Re: Chang'e 5
« Reply #35 on: December 02, 2020, 02:50:38 PM »
Of course that would mean more torque at the astronauts hands, that they may not have been able to combat.

Admit it.  You want to see an astronaut being flung around in a circle, completely horizontal in the low gravity, having a death grip on the handle of the drill.
"Facts are stubborn things." --John Adams

Offline Dalhousie

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Re: Chang'e 5
« Reply #36 on: December 02, 2020, 04:38:41 PM »
Of course that would mean more torque at the astronauts hands, that they may not have been able to combat.

Admit it.  You want to see an astronaut being flung around in a circle, completely horizontal in the low gravity, having a death grip on the handle of the drill.

Like this but with astronauts?


Offline Dalhousie

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Re: Chang'e 5
« Reply #37 on: December 02, 2020, 04:43:28 PM »
I'm curious to see how they store the drill samples - pointing out the difficulty of doing that robotically has long been part of my process of explaining how we know the Apollo samples were collected by people and not robots.

I always considered it to be a question of scale. Robotically collected Lunar samples were returned to Earth by the Soviets in the 1970s.. However they collected something like 380 grams. The Apollo samples had a total mass of three orders of magnitude higher.

Sorry, I meant specifically the drill samples. They're talking about drilling down 2 metres. So does that mean they're planning to somehow shoehorn a 2 metre sample tube into their ascent vehicle, or drill out shorter segments, or something else? Apollo 15 drilled down a little further, and it's been easy to explain how it simply wasn't practical for the robot technology of the time to retrieve such a long sample and transport it back to Earth - hence the need for astronauts.

So how is Chang'e 5 going to do something which required people at the time of Apollo?

The Luna sample return missions collected the drill core in a flexible tube that was coiled up inside the return capsule.

https://www.maxuta.com/maxuta/collections/032_pn_space_collectibles/032265_luna_24_model_with_soil_15.jpg

BTW Chang'e 5 is expected to return both core and scoop samples, totalling 2 kg.

Offline JayUtah

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Re: Chang'e 5
« Reply #38 on: December 02, 2020, 05:22:24 PM »
Like this but with astronauts?

Exactly like that, but with astronauts.  The flinging of equipment is a nice touch.
"Facts are stubborn things." --John Adams

Offline Dalhousie

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Re: Chang'e 5
« Reply #39 on: December 02, 2020, 06:15:09 PM »
Terminal descent video, video capture of screen unfortunately.  About 2.5 times actual speed.  Note the brief pause before final descent.  This is where the AI is scanning for obstacles.


https://twitter.com/i/status/1333959547979927555

Offline bknight

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Re: Chang'e 5
« Reply #40 on: December 02, 2020, 10:24:01 PM »
Of course that would mean more torque at the astronauts hands, that they may not have been able to combat.

Admit it.  You want to see an astronaut being flung around in a circle, completely horizontal in the low gravity, having a death grip on the handle of the drill.

It would have been amusing if it wasn't life threatening 240000 miles from medical help.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline Dalhousie

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Re: Chang'e 5
« Reply #41 on: December 03, 2020, 01:52:20 AM »

http://www.xinhuanet.com/english/2020-12/03/c_139560444.htm

BEIJING, Dec. 3 (Xinhua) -- China's Chang'e-5 probe has completed sampling on the moon, and the samples have been sealed inside the spacecraft, the China National Space Administration (CNSA) announced Thursday morning.

Launched on Nov. 24, the spacecraft landed on the north of the Mons Rumker in Oceanus Procellarum, also known as the Ocean of Storms, on the near side of the moon on Dec. 1, tasked with retrieving China's first samples from an extraterrestrial body.

After the spacecraft worked for about 19 hours on the moon, the sampling ended at 10:00 p.m. Wednesday (Beijing Time), and the samples were stowed in a container inside the ascender of the probe as planned, said CNSA.

By using data sent back by the probe, researchers simulated the sampling procedure in a lab, providing an important basis for the operation on the moon.

The lunar regolith penetrating radar and other payloads installed on the lander have carried out scientific exploration as planned and provided information support for sampling.

The probe has withstood temperatures of over 100 degrees Celsius on the lunar surface.

The probe has adopted two methods of moon sampling, including using drills to collect subsurface samples and grabbing samples on the surface with a robotic arm. Diverse samples at different sites have been gathered.

The moon samples have been sealed inside the spacecraft to ensure that they are kept in a vacuum and free from the influence of the external environment during its return to the Earth.

The Chang'e-5 probe is equipped with multiple payloads including a landing camera, panorama camera, lunar regolith penetrating radar and lunar mineralogical spectrometer, which detects lunar surface topography and mineral composition, as well as the moon's shallow subsurface structure.

Before the sample drilling process, the lunar regolith penetrating radar analyzed the subsurface structure in the sampling area, offering data reference for sampling.

Offline Dalhousie

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Re: Chang'e 5
« Reply #42 on: December 03, 2020, 01:53:37 AM »
Fingers crossed for launch in 8 hrs or so from now!

Offline Dalhousie

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Re: Chang'e 5
« Reply #43 on: December 03, 2020, 05:38:41 PM »
Fingers crossed for launch in 8 hrs or so from now!

Success!


Now for the big ones, first ever autonomous rendezvous, docking and sample transfer in lunar orbit.

Offline Dalhousie

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Re: Chang'e 5
« Reply #44 on: December 06, 2020, 05:34:24 AM »
Successful autonomous lunar orbit docking