China's moon lander.

[Tweeker]

From the press event a few weeks ago, here is a mock up of China's planned moon lander.  They are planning to use what they call "staged descent" It looks like the descent stage will take the lander most of the way to the surface, then be jettisoned. Then the lander will land {duh} and ascend after the mission. 

 

[tater]

Must be a crasher descent stage?

[sevenperforce]

Yep, looks exactly like the setup with the Blok D crasher stage under the lander on the N1's LK Lander. The LK had two engines: a central main engine and a backup engine with two nozzles mounted on either side of the main engine, and they were all shrouded with guards to protect them from debris at landing:

That's the propulsion unit for the lander; the lander is not attached in this image. Note the half-circle covers that fold down to protect the main nozzle. The four small nozzles are gas generator exhaust nozzles for the hypergolic (but not-pressure-fed) engine.

The Chinese lander looks like its landing legs will remain fixed to the lander during ascent. In contrast, the LK Lander jettisoned its landing leg assembly (which is why they don't show up in the image above) at liftoff, using it as a takeoff pad, to save mass. This also allows it to jettison the burnt-out settling motors that had fired at touchdown to help keep the vehicle from tipping.

[magnemoe]

6 hours ago, sevenperforce said:

Yep, looks exactly like the setup with the Blok D crasher stage under the lander on the N1's LK Lander. The LK had two engines: a central main engine and a backup engine with two nozzles mounted on either side of the main engine, and they were all shrouded with guards to protect them from debris at landing:

That's the propulsion unit for the lander; the lander is not attached in this image. Note the half-circle covers that fold down to protect the main nozzle. The four small nozzles are gas generator exhaust nozzles for the hypergolic (but not-pressure-fed) engine.

The Chinese lander looks like its landing legs will remain fixed to the lander during ascent. In contrast, the LK Lander jettisoned its landing leg assembly (which is why they don't show up in the image above) at liftoff, using it as a takeoff pad, to save mass. This also allows it to jettison the burnt-out settling motors that had fired at touchdown to help keep the vehicle from tipping.

Brings back an partially reusable Tylo lander in KSP 1, It had an crasher stage  but upper sage was reusable on other moons, Laythe with aerobrake and the other is easier, but Tylo required two stages. I brought two crasher stages so could do two landings. 
No I don't think China is planning on that. More likely that the legs are so lightweight that jettisoning them is not worth it, or its so simple as an servo moving an bolt.
 

[steve9728]

On 3/2/2023 at 10:24 PM, steve9728 said:

The shape of new manned spaceship (yeah still don't have a proper official name)'s propulsion module seems like to have a credible and significant changes

  Hide contents

The words are the guy's guessing on the Chinese forum. From the top to bottom are Hatch, Solar panels, Umbilical cables, Solar Sensors, and GNSS-like antennae

High temperature-resistant quartz antenna, Porthole, "We don't know what it is", Solar sensor, GNSS-like antennae, and Radiators

The manned lunar landing module

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From the top to bottom and left to right are: Docking mechanism, "Unknow equipment", Solar panels, Crane, Fuel tanks, Lunar rover, Hatch, Ladder, and Separation springs 

The target for manual docking, the optical target for automatic docking, "It should be a radar, but the model is too weird", the Omni-directional antenna to the rover and astronauts, and the Cylinders

Star sensors (2/3), Porthole, the Omni-directional antenna to the lunar surface, and the live equipments of the astronauts landing on the surface 

Star sensors (1/3), Far-field docking optical target, and the Omni-directional antenna to the lunar surface, 120° each

Via. https://weibo.com/2645044133/MuQxltSOJ

 

 

 

Not a press conference, but an exhibition at the National Museum of China, east of Tiananmen Square. I did think about taking the sleeper high speed train to Beijing with my girlfriend on Friday and then coming home from Beijing on Sunday night, and she: is there something wrong with you?

And that museum is the biggest museum in single building I ever been (not "single building" one is north of it, called the Forbidden City): from my experience, it is probably two to three times the size of the British Museum.

15 hours ago, magnemoe said:

No I don't think China is planning on that. More likely that the legs are so lightweight that jettisoning them is not worth it, or its so simple as an servo moving an bolt.

Yes, I remember there once the CNSA's official statement that the landing module is reusable. The general plan was to launch the manned module and the landing module separately and to dock them in lunar orbit. After the crew has entered the landing module and gone to the Moon, they return to lunar orbit in the landing module entirely. After docking, the crew will return to Earth in the manned module, while the landing module will remain in lunar orbit awaiting the next mission and refuelling.

I was thinking that if we could launch a module with multiple docking ports based on this, we would be able to perform more diverse tasks. But considering that CNSA's plan is to build a research station on the lunar surface, and that mankind has no experience in "Which is better? Building a space station in lunar orbit or a research station on the lunar surface?", this question is really worth discussing I think.

Edited March 14, 2023 by steve9728

[magnemoe]

1 hour ago, steve9728 said:

Not a press conference, but an exhibition at the National Museum of China, east of Tiananmen Square. I did think about taking the sleeper high speed train to Beijing with my girlfriend on Friday and then coming home from Beijing on Sunday night, and she: is there something wrong with you?

And that museum is the biggest museum in single building I ever been (not "single building" one is north of it, called the Forbidden City): from my experience, it is probably two to three times the size of the British Museum.

Yes, I remember there once the CNSA's official statement that the landing module is reusable. The general plan was to launch the manned module and the landing module separately and to dock them in lunar orbit. After the crew has entered the landing module and gone to the Moon, they return to lunar orbit in the landing module entirely. After docking, the crew will return to Earth in the manned module, while the landing module will remain in lunar orbit awaiting the next mission and refuelling.

I was thinking that if we could launch a module with multiple docking ports based on this, we would be able to perform more diverse tasks. But considering that CNSA's plan is to build a research station on the lunar surface, and that mankind has no experience in "Which is better? Building a space station in lunar orbit or a research station on the lunar surface?", this question is really worth discussing I think.

I say that is pretty cool, then they need to refuel and resupply the lander in addition to docking the decent module.  But you will be saving weight and money. 

 

[tater]

3 hours ago, steve9728 said:

Yes, I remember there once the CNSA's official statement that the landing module is reusable. The general plan was to launch the manned module and the landing module separately and to dock them in lunar orbit. After the crew has entered the landing module and gone to the Moon, they return to lunar orbit in the landing module entirely. After docking, the crew will return to Earth in the manned module, while the landing module will remain in lunar orbit awaiting the next mission and refuelling.

Would they dock a new "descent stage" to it in addition to refilling the lander?

[steve9728]

1 hour ago, tater said:

Would they dock a new "descent stage" to it in addition to refilling the lander?

Generally, the current idea is something like the manned module + lunar landing module + Earth-Moon transfer propulsion module. So, I think the "descent stage" on the exhibition is in one use: when it finishes its mission, it will be smashed on the moon. The new "descent stage" we expected is the Earth-Moon transfer propulsion module. The transfer module can back to the LEO and dock with CSS. Re-supply at this point would be simple, just launch a Tianzhou. You can ask google translate to help you with this paper, which is more current as it is from 2021: https://www.fx361.com/page/2021/0709/10846203.shtml

Edited March 14, 2023 by steve9728

[tater]

10 minutes ago, steve9728 said:

Generally, the current idea is something like the manned module + lunar landing module + Earth-Moon transfer propulsion module. So, I think the "descent stage" on the exhibition is in one use: when it finishes its mission, it will be smashed on the moon. The new "descent stage" we expected is the Earth-Moon transfer propulsion module. You can ask google translate to help you with this paper, which is more current as it is from 2021: https://www.fx361.com/page/2021/0709/10846203.shtml

Sensible for initial excursions. (I did this many times in KSP, lol).

Less of a good idea for a base architecture, as you don't want to be crashing stuff and randomly sending ejecta all over the place (necessarily in the region where you plan to land).

[steve9728]

6 minutes ago, tater said:

Less of a good idea for a base architecture, as you don't want to be crashing stuff and randomly sending ejecta all over the place (necessarily in the region where you plan to land).

Yes, it's mentioned in other papers that "although options for Americans to build space stations in lunar orbit is really expensive, but they can have more options for landing windows."

And there some schematics from some of the paper. Well, yes, it's from KSP. #RealLifeKerbalisms

Edited March 14, 2023 by steve9728

[tater]

As soon as anyone sets up any lunar infrastructure—a lunar base, occupied all the time or not, for example, or even unmanned astronomical observatories—crashers should be avoided by all parties I would think. Same might even be true if people start leaving infrastructure in (frozen) low lunar orbit, as ejecta can easily reach those sorts of altitudes.

It will be cool when we need lunar traffic control.

[steve9728]

2 minutes ago, tater said:

As soon as anyone sets up any lunar infrastructure—a lunar base, occupied all the time or not, for example, or even unmanned astronomical observatories—crashers should be avoided by all parties I would think. Same might even be true if people start leaving infrastructure in (frozen) low lunar orbit, as ejecta can easily reach those sorts of altitudes.

It will be cool when we need lunar traffic control.

And a trash disposal area and law/rules for any module finish its mission and smash on the moon.

[tater]

1 minute ago, steve9728 said:

And a trash disposal area and law/rules for any module finish its mission and smash on the moon.

Yeah, once people are there all the time, I think "crasher" stages should not be a thing unless they are staged such that they have residuals to allow for some sort of semi-controlled impact. Ie: they do a landing burn such that any ejecta is very localized. Hitting a a few hundred m/s is not a big deal, hitting at 2km/s is a problem.

[magnemoe]

5 hours ago, tater said:

Yeah, once people are there all the time, I think "crasher" stages should not be a thing unless they are staged such that they have residuals to allow for some sort of semi-controlled impact. Ie: they do a landing burn such that any ejecta is very localized. Hitting a a few hundred m/s is not a big deal, hitting at 2km/s is a problem.

Good point, and you will drop an crashing stage at pretty low velocity and if you have an base probably aim it for an crater or over an ridge to be safe. Also went the crasher stage so its no explosions. 
The problem is mostly with the landing engines is that the fast exhaust can push find dust to high velocity.  Its ways to deal with this like putting the landing engines high like in moonship or use lower Isp burns for landing. or you could land on an pad. 
 

[Superfluous J]

6 hours ago, tater said:

Sensible for initial excursions. (I did this many times in KSP, lol).

Less of a good idea for a base architecture, as you don't want to be crashing stuff and randomly sending ejecta all over the place (necessarily in the region where you plan to land).

I did *that* in KSP many times as well

[tater]

11 minutes ago, magnemoe said:

Good point, and you will drop an crashing stage at pretty low velocity and if you have an base probably aim it for an crater or over an ridge to be safe. Also went the crasher stage so its no explosions. 
The problem is mostly with the landing engines is that the fast exhaust can push find dust to high velocity.  Its ways to deal with this like putting the landing engines high like in moonship or use lower Isp burns for landing. or you could land on an pad. 
 

You can kill velocity at 3 km altitude and it hits at <100 m/s.

We can figure out what impact velocity is concerning, and kill velocity at a height such that it falls to the surface below that velocity.

[RCgothic]

"no crasher stages" is a particular issue for disposal of earth departure stages. Those come in especially hot & heavy.

Edited March 15, 2023 by RCgothic

[sevenperforce]

1 hour ago, RCgothic said:

"no crasher stages" is a particular issue for disposal of earth departure stages. Those come in especially hot.

Not to mention especially heavy. 

[StrandedonEarth]

If a suitable crater could be found that would contain the ejects, that would be great!  Perhaps an oblique impact at the base of a crater wall…

Or aim for one of those holes into a lava tube…

[steve9728]

I do think that somehow, we can learn from the experience in Antarctica. The rubbish of the people there is regularly taken away for disposal by ships from various countries. Several viable graveyard orbits would be carved out of the circumlunar orbit, and a satellite that could actively travel to these orbits to collect rubbish and haul it back to Earth would be launched periodically with crowdfunding from countries with scientific activities on the Moon. It would then back to Earth and be burned up in the atmosphere over the South Pacific under controlled.

But this idea is "a little less" feasible than the ideas of aiming for some proper craters to crash down or braking speed on impact