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How did China know how to make their rover without sending a bunch of probes onto Mars? Did NASA share its data and info with China so that they knew what specs

How did China know how to make their rover without sending a bunch of probes onto Mars? Did NASA share its data and info with China so that they knew what specs to make the solar panels, etc?

spaetzleesser 5y ago
Isn’t NASA pretty open with their designs? I don’t think it's hard to find their specs if you do some digging.
- abecedarius 5y ago
  Yeah. This sounds like a good place to start: https://www.amazon.com/Design-Engineering-Curiosity-Performs-Springer/dp/3319681443/ https://www.amazon.com/Design-Engineering-Curiosity-Performs...
Clewza313 5y ago
China has been sending probes to the Moon since 2007: https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Prog... Once you've got that down pat, it's not that different to land one on Mars, especially since the Chinese rover was small enough not to require the elaborate skyhook approach. Also, NASA is legally prohibited from cooperating with China on anything space-related.
- plank_time 5y ago
  Of course it’s different. You need to know how to make solar panels so that it will work on Mars. It’s different than those you would need for the moon. It would have to work through the dust storms. The equipment would need to be rated differently. How the signal is sent from the rover to the orbiter would be different, etc. There’s a lot of knowledge that you would need to build up about Mars and having probes on Mars and the logistics of sending data to and from Earth via orbiter that you would need before jumping all the way to sending a large expensive rover to Mars. That’s interesting about NASA not being allowed to share data. I really wonder how China was able to leap to sending a rover without lots of investment in understanding everything else about it.
  - icegreentea2 5y ago
    Many of the design outputs of the NASA rover programs are public domain. For example, the peak solar panel rating of the MER (Opportunity and Spirit) is published, the size of the panels are known (or can easily by estimated), the power needed to drive the rovers around is published, the weight of the rover is published, the size of wheels can be easily estimated (or is published). The logistics of sending data back can be reasonably considered to be a challenge that could be solved on the first try. The first space probe that NASA managed to actually get to Mars (Mariner) worked. The first landers that NASA managed to get to Mars (Viking) worked.
  - unity1001 5y ago
    > I really wonder how China was able to leap to sending a rover without lots of investment in understanding everything else about it. Continent-wide public education churning out legions after legions of STEM graduates?
    - cscurmudgeon 5y ago
      The best of which promptly move to US and Europe.
      - onethought 5y ago
        I think you severely underestimate the quantity of top scoring STEM graduates. What you really mean is “the richest/privileged move to US and Europe”
    - sidlls 5y ago
      The proportion of Chinese stem graduates who aren’t simply copying their way around and are gifted enough to run these programs is likely about the same as the proportion anywhere else. Chinese people are no more or less intelligent than anyone else.
      - ptr2voidStar 5y ago
        Shocking that you have to state this fact. Is this HN or YouTube? SMDH
- myrandomcomment 5y ago
  It’s completely different. Let’s start with the moon has no atmosphere so you do not use parachutes to land on the moon like you do on Mars. Your statement is nonsense.
  - Clewza313 5y ago
    Of course it's different, but you're still sending a probe to a celestial body, so things like building the rocket, designing radiation-hardened hardware, space communications, launching on a desired trajectory, automated landing with retro-propulsion etc are all similar and needed for both. Basically, if you're going to practice the Moon is the place to do it, and that's why the US, Soviet, Chinese and now Indian space programs are all following the same basic game plan.
sinxccc 5y ago
That's why the rover landing happened 3 months after the probe reached Mars orbit. They spent that time to do all the reconnaissance work to prepare the landing. Also this is the reason this mission is considered to be a great success, it shows their ability to landing on a totally unknown planet.
EMM_386 5y ago
> How did China know how to make their rover without sending a bunch of probes onto Mars? Why would they need probes? The Mars atmospheric composition isn't exactly classified information, they know it's a solid surface. The rest is just math and some very complex engineering.
russli1993 5y ago
CNSA did acknowledge that they benefited from prior explorations to mars done by everyone, including NASA, soviet union, ESA and more. They are able to find general scientific data on mars, such as atmospheric density, composition, potential weather events, general topography in the public domain (I mean, wikiepdia has a lot of these information). For these, they should and are appreciating scientists going before them are sharing these information in the public domain. But I am sure NASA and everyone else did not release all super detailed data, such as detailed topology maps. And from public available info, they also know about general designs of NASA's landers and rovers, and the troubles NASA has faced operating these crafts on mars. If they learn from NASA's experiences, they can avoid a huge amount of unknowns and negative encounters. These are significant assistance when you are engineering systems. The pioneer is always way more difficult. So of course respect is paid and hats off to NASA and other pioneers. But knowing these are not enough for you to build and operate a fully successful mission. Even if you had the entire CAD file of a NASA lander and rover, you don't know why they are designed that way, you will not operate, use and troubleshoot issues correctly. You need to build the system from ground up, so the people on your teams have full understanding of every single "why" and "how". Only then will you have full control and ensure the mission is success. I am sure you had experience taking ownership to a software project written by others. You always have go to the original designer to ask "why" and "how". The knowledge transfer often last months and countless meetings. If you don't fully understand, you can't fix issues or build new features. Most people would rather build their own then to fix something they don't fully understand. For CNSA, they can access public available data. Then they have to simulate, wind tunnel tests, how to land, what shape of lander they need, how to balance and control the lander etc. They need to build up their understanding of the entire system. They actually has been improving their technology and understanding of atmospheric and controlled powered landing from earth and moon missions. One of things they did differently is adding a flap to the lander to stabilize it in flight, they said it was to increase the lander's robustness when encountering more extreme weather. For solar panels, knowing the distance to the sun, the atmospheric density, pressure, composition, force of gravity on mars, you can estimate the theoretical max of the solar energy available per unit of area. Then you could say assume only 30% is available due to weather. I am sure they have more advanced ways to estimate. Interesting fact about the rover, it has a solar heat capture and retention system. And they use the heat for thermo-control at night instead of electricity captured from solar panels, saving electricity use. For where to land, topology and maps of mars is in public domain. You can find a general region where to land but these data are not detailed enough to actually land. And mars surface could have changed since these were captured. So tianwen-1 contains a orbiter and the lander. The orbiter has instruments such has high resolution imaging. They arrived mars orbit in February, and the 3 months since the orbiter was collecting data on mars. From these data they finalized their landing plans. This is China's first spacecraft to ever travel this far. They also don't have communication network between mars and earth. So Tianwen-1's orbiter is also a communication satellite. The impressive thing is the engineering side, how they engineered the system that each component all worked correctly in one go. The rocket: the rocket required to launch tianwen-1 (weighs 5 tons) to mars orbit was only tested successfully in dec 2019. China also doesn't have earth mars communication satellites and fully operational deep space communication system before this mission. This the first time all these system are tested live. To fly a spacecraft to mars for the first time, have it being captured by mars, and orbit mars correctly. Take data on mars. Release the lander. The lander going through atmosphere, releasing parachute at super sonic speeds, the lander detaches from parachute and uses a rocket engine to fly. At height of 100m, optical imaging and laser maps out the ground and autonomously navigate the craft to soft land on flat ground. Orbiter forms communication link between mars rover and earth. Mars rover collects sun light, drives, survives the elements of mars (so far). Overall, they are standing on the shoulders of people who went before them. One shouldn't look down on their success, nor should they over-hype their success. CNSA said Zhurong landed 3km away from their designed coordinate. For the first 42 mars days, zhurong traveled 236m.

How did China know how to make their rover without sending a bunch of probes onto Mars? Did NASA share its data and info with China so that they knew what specs to make the solar panels, etc?

spaetzleesser 5y ago

Isn’t NASA pretty open with their designs? I don’t think it's hard to find their specs if you do some digging.

abecedarius 5y ago
Yeah. This sounds like a good place to start: https://www.amazon.com/Design-Engineering-Curiosity-Performs-Springer/dp/3319681443/ https://www.amazon.com/Design-Engineering-Curiosity-Performs...

Clewza313 5y ago

China has been sending probes to the Moon since 2007: https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Program https://en.wikipedia.org/wiki/Chinese_Lunar_Exploration_Prog... Once you've got that down pat, it's not that different to land one on Mars, especially since the Chinese rover was small enough not to require the elaborate skyhook approach. Also, NASA is legally prohibited from cooperating with China on anything space-related.

plank_time 5y ago
Of course it’s different. You need to know how to make solar panels so that it will work on Mars. It’s different than those you would need for the moon. It would have to work through the dust storms. The equipment would need to be rated differently. How the signal is sent from the rover to the orbiter would be different, etc. There’s a lot of knowledge that you would need to build up about Mars and having probes on Mars and the logistics of sending data to and from Earth via orbiter that you would need before jumping all the way to sending a large expensive rover to Mars. That’s interesting about NASA not being allowed to share data. I really wonder how China was able to leap to sending a rover without lots of investment in understanding everything else about it.
- icegreentea2 5y ago
  Many of the design outputs of the NASA rover programs are public domain. For example, the peak solar panel rating of the MER (Opportunity and Spirit) is published, the size of the panels are known (or can easily by estimated), the power needed to drive the rovers around is published, the weight of the rover is published, the size of wheels can be easily estimated (or is published). The logistics of sending data back can be reasonably considered to be a challenge that could be solved on the first try. The first space probe that NASA managed to actually get to Mars (Mariner) worked. The first landers that NASA managed to get to Mars (Viking) worked.
- unity1001 5y ago
  > I really wonder how China was able to leap to sending a rover without lots of investment in understanding everything else about it. Continent-wide public education churning out legions after legions of STEM graduates?
  - cscurmudgeon 5y ago
    The best of which promptly move to US and Europe.
    - onethought 5y ago
      I think you severely underestimate the quantity of top scoring STEM graduates. What you really mean is “the richest/privileged move to US and Europe”
  - sidlls 5y ago
    The proportion of Chinese stem graduates who aren’t simply copying their way around and are gifted enough to run these programs is likely about the same as the proportion anywhere else. Chinese people are no more or less intelligent than anyone else.
    - ptr2voidStar 5y ago
      Shocking that you have to state this fact. Is this HN or YouTube? SMDH
myrandomcomment 5y ago
It’s completely different. Let’s start with the moon has no atmosphere so you do not use parachutes to land on the moon like you do on Mars. Your statement is nonsense.
- Clewza313 5y ago
  Of course it's different, but you're still sending a probe to a celestial body, so things like building the rocket, designing radiation-hardened hardware, space communications, launching on a desired trajectory, automated landing with retro-propulsion etc are all similar and needed for both. Basically, if you're going to practice the Moon is the place to do it, and that's why the US, Soviet, Chinese and now Indian space programs are all following the same basic game plan.

sinxccc 5y ago

That's why the rover landing happened 3 months after the probe reached Mars orbit. They spent that time to do all the reconnaissance work to prepare the landing. Also this is the reason this mission is considered to be a great success, it shows their ability to landing on a totally unknown planet.

EMM_386 5y ago

> How did China know how to make their rover without sending a bunch of probes onto Mars? Why would they need probes? The Mars atmospheric composition isn't exactly classified information, they know it's a solid surface. The rest is just math and some very complex engineering.

russli1993 5y ago

CNSA did acknowledge that they benefited from prior explorations to mars done by everyone, including NASA, soviet union, ESA and more. They are able to find general scientific data on mars, such as atmospheric density, composition, potential weather events, general topography in the public domain (I mean, wikiepdia has a lot of these information). For these, they should and are appreciating scientists going before them are sharing these information in the public domain. But I am sure NASA and everyone else did not release all super detailed data, such as detailed topology maps. And from public available info, they also know about general designs of NASA's landers and rovers, and the troubles NASA has faced operating these crafts on mars. If they learn from NASA's experiences, they can avoid a huge amount of unknowns and negative encounters. These are significant assistance when you are engineering systems. The pioneer is always way more difficult. So of course respect is paid and hats off to NASA and other pioneers. But knowing these are not enough for you to build and operate a fully successful mission. Even if you had the entire CAD file of a NASA lander and rover, you don't know why they are designed that way, you will not operate, use and troubleshoot issues correctly. You need to build the system from ground up, so the people on your teams have full understanding of every single "why" and "how". Only then will you have full control and ensure the mission is success. I am sure you had experience taking ownership to a software project written by others. You always have go to the original designer to ask "why" and "how". The knowledge transfer often last months and countless meetings. If you don't fully understand, you can't fix issues or build new features. Most people would rather build their own then to fix something they don't fully understand. For CNSA, they can access public available data. Then they have to simulate, wind tunnel tests, how to land, what shape of lander they need, how to balance and control the lander etc. They need to build up their understanding of the entire system. They actually has been improving their technology and understanding of atmospheric and controlled powered landing from earth and moon missions. One of things they did differently is adding a flap to the lander to stabilize it in flight, they said it was to increase the lander's robustness when encountering more extreme weather. For solar panels, knowing the distance to the sun, the atmospheric density, pressure, composition, force of gravity on mars, you can estimate the theoretical max of the solar energy available per unit of area. Then you could say assume only 30% is available due to weather. I am sure they have more advanced ways to estimate. Interesting fact about the rover, it has a solar heat capture and retention system. And they use the heat for thermo-control at night instead of electricity captured from solar panels, saving electricity use. For where to land, topology and maps of mars is in public domain. You can find a general region where to land but these data are not detailed enough to actually land. And mars surface could have changed since these were captured. So tianwen-1 contains a orbiter and the lander. The orbiter has instruments such has high resolution imaging. They arrived mars orbit in February, and the 3 months since the orbiter was collecting data on mars. From these data they finalized their landing plans. This is China's first spacecraft to ever travel this far. They also don't have communication network between mars and earth. So Tianwen-1's orbiter is also a communication satellite. The impressive thing is the engineering side, how they engineered the system that each component all worked correctly in one go. The rocket: the rocket required to launch tianwen-1 (weighs 5 tons) to mars orbit was only tested successfully in dec 2019. China also doesn't have earth mars communication satellites and fully operational deep space communication system before this mission. This the first time all these system are tested live. To fly a spacecraft to mars for the first time, have it being captured by mars, and orbit mars correctly. Take data on mars. Release the lander. The lander going through atmosphere, releasing parachute at super sonic speeds, the lander detaches from parachute and uses a rocket engine to fly. At height of 100m, optical imaging and laser maps out the ground and autonomously navigate the craft to soft land on flat ground. Orbiter forms communication link between mars rover and earth. Mars rover collects sun light, drives, survives the elements of mars (so far). Overall, they are standing on the shoulders of people who went before them. One shouldn't look down on their success, nor should they over-hype their success. CNSA said Zhurong landed 3km away from their designed coordinate. For the first 42 mars days, zhurong traveled 236m.